research articles on steroids

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• v.14(2); Summer 2014

Steroids: Pharmacology, Complications, and Practice Delivery Issues

William ericson-neilsen.

1 Department of Anesthesiology, Ochsner Clinic Foundation, New Orleans, LA

Alan David Kaye

2 Departments of Anesthesiology and Pharmacology, Louisiana State University Health Sciences Center, New Orleans, LA

Since their identification nearly 80 years ago, steroids have played a prominent role in the treatment of many disease states. Many of the clinical roles of steroids are related to their potent antiinflammatory and immune-modulating properties.

This review summarizes the basic pharmacology, complications, and practice delivery issues regarding steroids.

Clinically relevant side effects of steroids are common and problematic. Side effects can occur at a wide range of doses and vary depending on the route of administration. The full spectrum of side effects can be present even in patients taking low doses.

Conclusions

Practitioners must be aware that these drugs might exacerbate a preexisting condition or present a new medical condition. Knowledge of the clinical implications of prescribing these agents is critical.

INTRODUCTION

Since their identification in 1935, steroids have served a wide range of uses. Initially, these isolates from adrenal glands were thought to be useful only in patients suffering from Addison disease. 1 Today, many of the clinical roles of steroids are related to their potent antiinflammatory and immune-modulating properties. Clinically relevant side effects of steroids are common and problematic, ranging from a minor case of acne to Cushing syndrome that can result in diabetes mellitus and potentially life-threatening heart disease if untreated. 2 Side effects can occur at a wide range of doses and vary depending on the route of administration. 1

The term steroid applies to a wide range of molecules with varying physiological effects. More specifically, corticosteroids are a class of chemicals encompassing both laboratory-synthesized and naturally produced hormones. Glucocorticoids, in general, regulate metabolism and inflammation; mineralocorticoids regulate sodium and water levels. Corticosteroids fall along a spectrum from exclusively glucocorticoid effects to exclusively mineralocorticoid effects, and steroid compounds are selected based on their appropriateness for a given treatment. For example, although a compound may possess potent antiinflammatory properties, it may additionally have mineralocorticoid activity that adversely affects blood pressure.

CORTICOSTEROID METABOLISM AND CLINICAL ROLE

Although corticosteroid metabolism is complicated by enzyme induction, protein binding, molecular interconversion, and interaction with endogenous cortisol, corticosteroids are generally metabolized by the hepatic P450 system. 3 Direct application (eg, topical, intraarticular, inhaled, or epidural) of these agents to sites of inflammation bypasses the liver and its first-pass effect.

Chronic oral glucocorticoid use is common in patients with rheumatoid arthritis, chronic obstructive pulmonary disease, systemic lupus erythematosus, inflammatory bowel disease, and asthma. 4 Side effects of chronic use include bruising, muscle weakness, weight gain, skin changes, sleep disturbances, cataracts, and pathologic fractures. 4 Glucocorticoid administration can also have psychiatric side effects: mood disorders, anxiety, delirium, and panic disorder. Psychotropic medication may be required to treat these symptoms, but the prognosis is favorable once the glucocorticoids are reduced or discontinued. 5 - 7 Adverse effects occur in up to 90% of patients who take glucocorticoids for >60 days. 4 These side effects, including the more serious fractures and cataracts, occur even in patients taking low (≤7.5 mg/d) dosages. 4 , 8

Glucocorticoids affect bone mineralization by inhibiting calcium absorption in the gastrointestinal tract and shifting signaling-molecule production to favor bone resorption. 8 Recommendations for preventing glucocorticoid-induced osteopenia and its subsequent complications and comorbidities include supplementing calcium with vitamin D for glucocorticoid doses ≥5 mg/d and starting bisphosphonates when indicated by densiometric evaluation. 8

Because of their effects on insulin resistance, glucocorticoids are the most common cause of drug-induced diabetes mellitus. 9 Screening guidelines using a fasting glucose ≥126 mg/dL or HbA1c ≥6.5% are suitable for diagnosing steroid-induced diabetes; however, per American Diabetes Association guidelines, results should be confirmed via repeat testing. 9 Management is similar to that of type 2 diabetes mellitus; treatment options progress from single agent to double agent to insulin ± another agent, based upon fasting glucose measurements and glucose control. 9 In patients with preexisting diabetes, blood sugars should be measured more often than in patients without preexisting diabetes, and medications should be adjusted to maintain adequate control. 9

Cushing syndrome and adrenal suppression have been observed in patients taking oral, intraarticular, epidural, inhaled, nasal, ocular, and topical glucocorticoid preparations. 8 , 9 These side effects become more likely with longer durations of treatment and higher dosages. 8 , 9

Mineralocorticoid activity causes the retention of sodium and free water and the excretion of potassium. 2 Derangements in mineralocorticoid production can manifest with abnormalities in any of these areas. Hyponatremia, hyperkalemia, and hypotension are present to varying degrees in mineralocorticoid-deficient states (eg, various congenital adrenal hyperplasias and aldosterone synthase deficiency), whereas the inverse is present in mineralocorticoid-excess states (eg, Conn syndrome). Because endogenous glucocorticoids also have activity at mineralocorticoid receptors, signs and symptoms of mineralocorticoid excess can be seen in cases of excess glucocorticoid production (eg, Cushing syndrome). 2

CORTICOSTEROID PREPARATIONS

Steroid injections are associated with side effects related to dosage, duration of administration, added ingredients or contaminates, and particle size. Particulate steroids present a theoretical risk of occluding vessels depending on the size of particulate aggregates. 10 Common additives in steroid preparations, such as benzyl alcohol and ethylene glycol, have been implicated in case reports and studies of complications following epidural steroid administration. 10 , 11 Dexamethasone and betamethasone sodium phosphate are pure liquids, whereas methylprednisolone, triamcinolone, and betamethasone are solutions, and their particle size depends upon the type of preparation and dosage. Studies have shown that transforaminal dexamethasone is just as effective at 4 mg as it is at 8 mg and 12 mg and that nonparticulate steroid preparations are just as effective as particulate preparations in treating cervical radicular pain. 12 , 13 Methylprednisolone and triamcinolone are the drugs most commonly used for epidural steroid injections. Common side effects of epidural steroid injections are paresthesia, pain on injection, intravascular injection, bleeding, and dysesthesia. 12 The most serious complications of epidural steroid injections are related to intravascular injections. Intraarterial injections may occur even with a negative aspirate and have been shown to potentially cause paraplegia. 14 Although the use of computed tomography guidance instead of conventional fluoroscopy provides a better image of relevant anatomy, it does not assure avoidance of these adverse events. 14

Topical corticosteroids (2.5% ointment, triamcinolone 0.1% ointment, and clobetasol propionate 0.05% foam) achieve more effective skin concentrations than oral prednisone. 15 Side effects, including skin thinning, color change, and systemic effects, can be expected with topical application of corticosteroids and increase in a dose-dependent manner. 16 Inhaled corticosteroids have evolved into a mainstay of therapy for moderate to severe asthma. Effectiveness and systemic bioavailability vary with each corticosteroid molecule and dosage, but in general, systemic effects are minimized with proper administration. 17 Common side effects of inhaled corticosteroids include gingival irritation and oral candidiasis, as well as the many systemic effects associated with corticosteroid use. 17 , 18

Fludrocortisone is a synthetic corticosteroid that has potent mineralocorticoid effects. 2 It has been used clinically to achieve the mineralocorticoid effects of sodium and water retention in cases of cerebral salt wasting, orthostatic hypotension, and adrenocortical insufficiency in Addison disease. 19 - 21 Potassium wasting is a common side effect of fludrocortisone administration, and electrolyte levels should be monitored while a patient is undergoing fludrocortisone administration. 21

The potencies of corticosteroids vary widely, with synthetic compounds generally retaining greater antiinflammatory potency and weaker salt-retaining properties; these potencies are summarized in the Table .

Basic Potency, Duration of Action, and Equivalent Dose of Typical Steroid Preparations

MECHANISTIC PHARMACOLOGY AND PHYSIOLOGY OF STEROIDS

The antiinflammatory properties of steroids have been attributed to their inhibitory effects on the action of phospholipase A2, an enzyme critical to the production of inflammatory compounds. 22 Research has shown that steroids are active in affecting gene expression, translation, and enzyme activity. 23 In short, they bring about their physiologic effects through a multitude of biochemical pathways. 23 One such pathway is through their induction of the production of proteins called lipocortins. Glucocorticoids stem the production of inflammatory mediators such as leukotrienes and prostaglandins and effectively halt the inflammatory cascade. 22 , 24 As their wide-ranging side effects indicate, glucocorticoids can impact many systems throughout the body. Through negative feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis, exogenous glucocorticoids can directly induce hypopituitarism (Addison disease). 2 , 25 Their actions on glucose metabolism can increase insulin resistance in tissues and increase fasting glucose levels. 2 , 25 Glucocorticoids can act directly on osteoclasts to affect bone resorption and decrease calcium absorption in the gastrointestinal tract, resulting in osteopenia and osteoporosis. 2 , 25

Because of the wide-ranging effects that glucocorticoids can have on a patient's body and on the HPA axis in particular, a practitioner must be careful when discontinuing their administration. If steroids have been administered for less than 1 week, they can be stopped without tapering. For dosing lasting 1-3 weeks, tapering should be based upon clinical conditions and the illness for which the medication was prescribed. 9 When the patient has taken glucocorticoids for more than 3 weeks, the practitioner's goal is a quick tapering to physiologic doses and then a slow decrease in dosage while evaluating adrenal function. 4 For patients who are taking equivalent doses of 30 mg of hydrocortisone daily or have established HPA axis dysfunction and are under stress (eg, major surgery, critical illness, trauma), an increased dosing of steroids (intravenous or intramuscular hydrocortisone) is recommended every 6 hours for 24 hours, followed by a tapering to the previous maintenance dose by 50% per day. 25

Mineralocorticoids, endogenously represented by aldosterone and deoxycorticosterone, effect physiologic changes by altering electrolyte (sodium and potassium) levels, causing volume changes to occur. 2 Rather than being moderated by the HPA axis as glucocorticoid production is, mineralocorticoid production is mainly regulated by the renin-angiotensin-aldosterone system, although adrenocorticotropic hormone, a product of the HPA axis, does have minimal activity in stimulating aldosterone release. 2

CONTROVERSY WITH STEROID PREPARATION

Recent developments involving both morbidity (751 total infections in 20 states as of October 2013) and mortality (64 deaths over the same time period) related to steroid compounds manufactured at the New England Compounding Center (NECC) show that the side effects of steroid injections range beyond those that can be explained by the physiologic and pharmacologic properties of glucocorticoids. 26 The glucocorticoid preparations implicated in the nationwide fungal meningitis outbreak were manufactured at a compounding pharmacy, a facility that was neither licensed nor inspected by the United States Food and Drug Administration (FDA) for large-scale pharmaceutical manufacturing but was under regulation by the state pharmacy board in Massachusetts. 27 Traditionally, physicians turn to local compounding pharmacies to prepare mainstream pharmaceuticals that either are not offered in the concentration required for patient administration or are not compatible with a particular route of administration. Compounding pharmacies historically have been licensed to produce these medications for individual patients in quantities suitable to fill the prescription. 27 Physicians also turn to compounding pharmacies to manufacture drugs for individual patient administration when FDA-approved drugs are not available through traditional distribution channels. 27 Such pharmaceuticals may contain the same active ingredients as FDA-approved medications, but the potency and concentrations of the active ingredients vary greatly (from 68.5% to 265.4%). 27 Although the FDA views compounded pharmaceuticals as unapproved new drugs because of their untested nature, the recent inspections of compounding pharmacies and the enforcement of laws regulating them have focused on the pharmacies effectively operating as drug manufacturing companies that distribute their compounded pharmaceuticals nationwide, rather than those that serve individual patients locally, such as NECC. 27

Multiple reports of fungal meningitis occurring after epidural steroid injection prompted an FDA inspection of the NECC pharmacy facilities and revealed a number of problems with manufacturing process and facilities, ranging from stagnant puddles of water in autoclaves to visible discoloration and fungal growth around the facilities. 26 , 28 An examination of 321 recalled vials of methylprednisolone acetate revealed that 100 of these vials contained visible foreign matter. 28 This finding shows that although physicians may not play a direct role in the manufacture of the compounds administered to patients, they can play a crucial role in the quality control process by simply looking at the compounds they give to their patients.

The laws governing compounding pharmacies and their regulation have recently been revised with the passage of the Drug Quality and Security Act signed on November 27, 2013. With this new law and revisions made to the Federal Food, Drug and Cosmetic Act (section 503A provided the exemptions for compounding pharmacies from compliance with current good manufacturing practices [CGMP], FDA approval prior to marketing, and labeling with adequate directions for use), compounding pharmacies can become “outsourcing facilities” and be placed under FDA regulation. 29 The new laws mandate compounding pharmacies to comply with CGMP requirements, to be inspected by the FDA on a risk-based schedule if they are an “outsourcing facility,” and to report adverse events to the FDA. 29

Since their discovery, steroids have infiltrated nearly every branch of medicine and can be administered in nearly every route available. The effects of steroid use can vary widely, and the full spectrum of side effects can be present even in patients taking low doses. Practitioners must be aware that the drug can possibly exacerbate a preexisting condition or present a new medical condition. Knowledge of the clinical implications of prescribing these agents is critical.

The authors have no financial or proprietary interest in the subject matter of this article .

This article meets the Accreditation Council for Graduate Medical Education and the American Board of Medical Specialties Maintenance of Certification competencies for Patient Care and Medical Knowledge.

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts

Steroid hormones articles within Nature Reviews Endocrinology

Research Highlight | 22 March 2023

CITED1 mediates sex-specific regulation of food intake in hypothalamic neurons

• Olivia Tysoe

Review Article | 11 October 2022

The ATP-binding cassette proteins ABCB1 and ABCC1 as modulators of glucocorticoid action

This Review discusses the ATP-binding cassette (ABC) proteins ABCB1 and ABCC1 and their preferential cellular export of cortisol and corticosterone, respectively. The article also explores the potential to select therapeutic glucocorticoids on the basis of their different tendencies for export to avoid harmful adverse effects.

• Kerri Devine
• , Elisa Villalobos
•  &  Brian R. Walker

Research Highlight | 20 February 2020

Genetic analysis reveals role of testosterone levels in human disease

• Claire Greenhill

Research Highlight | 21 January 2019

A new class of AR antagonists?

• Annette Fenner

Opinion | 08 September 2017

Chronic endocrine consequences of traumatic brain injury — what is the evidence?

In this Opinion article, Klose and Feldt-Rasmussen posit that the true risk and disease burden of hypopituitarism after traumatic brain injury might have been overestimated in recent years. Possible reasons for this overestimation are discussed, along with current recommendations for diagnosing and treating the condition.

• Marianne Klose
•  &  Ulla Feldt-Rasmussen

In Brief | 30 January 2017

Metformin reduces adverse effects of glucocorticoid treatment

Research Highlight | 02 September 2016

Paradigm shift for ACTH suppression

• David Holmes

Review Article | 27 May 2014

Glucocorticoids and fetal programming part 2: mechanisms

Fetal exposure to increased levels of glucocorticoids can lead to long-term 'programming' of hypothalamic–pituitary–adrenal function and behaviours. This Review discusses the mechanisms underlying fetal glucocorticoid programming, including epigenetic modifications, as well as the mechanisms of transgenerational programming.

• Vasilis G. Moisiadis
•  &  Stephen G. Matthews

Glucocorticoids and fetal programming part 1: outcomes

The fetal hypothalamic–pituitary–adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids, which can have long-term effects. Here, the evidence regarding fetal programming of the HPA axis and behaviour in humans and animals after prenatal glucocorticoid exposure (either endogenous or synthetic) are discussed.

In Brief | 24 December 2013

Androgens, autophagy and apoptosis

Year in Review | 24 December 2013

Glucocorticoids—timing, binding and environment

2013 has revealed interesting mechanisms that explain how glucocorticoid signalling responses can be influenced by childhood trauma, activity of other signalling molecules, glucocorticoid circadian rhythms and the sequence of DNA regulatory regions. In particular, studies this year highlight how different signalling environments can determine the molecular and physiological responses of glucocorticoids themselves, and how glucocorticoids can affect other signalling systems.

• Stafford L. Lightman
•  &  Charlotte L. George

Research Highlight | 17 December 2013

Bilateral macronodular adrenal hyperplasia—new genetic and pathophysiological insights

• Carol Wilson

News & Views | 29 October 2013

Hormone therapy to treat menopause—breaking a taboo

Findings from the Women's Health Initiative hormone study send the message that clinicians can feel confident prescribing menopausal hormone replacement therapy (MHT) to young menopausal women with moderate-to-severe symptoms who do not have absolute contraindications for hormone therapy. However, MHT is indicated for the alleviation of symptoms, not for chronic disease prevention.

• Susan R. Davis

News & Views | 22 October 2013

Estrogens—not just female hormones

In a carefully conducted, outstanding example of clinical research, Finkelstein et al . clearly demonstrate the physiological underpinnings for the action of testosterone and the relative roles of its androgenic and estrogenic effects on body composition and sexual function. This study has important clinical implications for testosterone replacement therapy of male hypogonadism.

• Alvin M. Matsumoto

Review Article | 01 October 2013

Glucocorticoid sensitivity in health and disease

Glucocorticoids are involved in the regulation of many physiological processes and are essential to the systemic response to stress. This Review outlines recent insights into the mechanisms that influence glucocorticoid sensitivity in health and disease and discusses possible strategies to modulate glucocorticoid sensitivity and improve the outcomes of glucocorticoid therapy.

• Rogier A. Quax
• , Laura Manenschijn
•  &  Richard A. Feelders

Review Article | 17 September 2013

The role of estrogen and androgen receptors in bone health and disease

This Review describes the effects of ERα, AR and RANKL in various cell types involved in bone homeostasis. The authors discuss the implications of findings in animal models for understanding the regulation of trabecular and cortical bone, the integration of hormonal and mechanical signals, as well as the importance of estrogens and androgens in the female versus male skeleton.

• Stavros C. Manolagas
• , Charles A. O'Brien
•  &  Maria Almeida

Review Article | 27 November 2012

Gonadal steroids and humoral immunity

Advances in understanding of B-lymphocyte maturation and immune tolerance are yielding new insight into the influence of gonadal steroids on the humoral immune system. Kovacs and colleagues examine how oestrogens and androgens directly and indirectly modulate B-lymphocyte development and function, focusing on B lymphopoiesis, elimination of autoreactive B-cell clones, and generation of high-affinity, class-switched, immunoglobulin-producing B cells.

• Sanaz Sakiani
• , Nancy J. Olsen
•  &  William J. Kovacs

Research Highlight | 21 October 2010

Low testosterone increases risk of cardiovascular events in women

Editorial | 01 August 2010

Game over for sports cheats?

• Vicky Heath

News & Views | 01 June 2010

Polycystic ovary syndrome: steroid assessment for diagnosis

Hyperandrogenism is the key pathologic feature of polycystic ovary syndrome, but diagnostic assessment of androgen excess in women is problematic, and the biochemical assays in routine clinical practice are largely considered uninformative. Is it time to add new diagnostic modalities to the clinical toolbox and perhaps measure levels of estrogen instead?

• Theresa E. Hickey
•  &  Robert J. Norman

Browse broader subjects

Quick links.

• Explore articles by subject
• Guide to authors
• Editorial policies

Featured Clinical Reviews

• Screening for Atrial Fibrillation: US Preventive Services Task Force Recommendation Statement JAMA Recommendation Statement January 25, 2022
• Evaluating the Patient With a Pulmonary Nodule: A Review JAMA Review January 18, 2022

Select Your Interests

Customize your JAMA Network experience by selecting one or more topics from the list below.

• Academic Medicine
• Acid Base, Electrolytes, Fluids
• Allergy and Clinical Immunology
• American Indian or Alaska Natives
• Anesthesiology
• Anticoagulation
• Art and Images in Psychiatry
• Artificial Intelligence
• Assisted Reproduction
• Bleeding and Transfusion
• Caring for the Critically Ill Patient
• Challenges in Clinical Electrocardiography
• Climate and Health
• Climate Change
• Clinical Challenge
• Clinical Decision Support
• Clinical Implications of Basic Neuroscience
• Clinical Pharmacy and Pharmacology
• Complementary and Alternative Medicine
• Consensus Statements
• Coronavirus (COVID-19)
• Critical Care Medicine
• Cultural Competency
• Dental Medicine
• Dermatology
• Diabetes and Endocrinology
• Diagnostic Test Interpretation
• Drug Development
• Electronic Health Records
• Emergency Medicine
• End of Life, Hospice, Palliative Care
• Environmental Health
• Equity, Diversity, and Inclusion
• Facial Plastic Surgery
• Gastroenterology and Hepatology
• Genetics and Genomics
• Genomics and Precision Health
• Global Health
• Guide to Statistics and Methods
• Hair Disorders
• Health Care Delivery Models
• Health Care Economics, Insurance, Payment
• Health Care Quality
• Health Care Reform
• Health Care Safety
• Health Care Workforce
• Health Disparities
• Health Inequities
• Health Policy
• Health Systems Science
• History of Medicine
• Hypertension
• Images in Neurology
• Implementation Science
• Infectious Diseases
• Innovations in Health Care Delivery
• JAMA Infographic
• Law and Medicine
• Leading Change
• Less is More
• LGBTQIA Medicine
• Lifestyle Behaviors
• Medical Coding
• Medical Devices and Equipment
• Medical Education
• Medical Education and Training
• Medical Journals and Publishing
• Mobile Health and Telemedicine
• Narrative Medicine
• Neuroscience and Psychiatry
• Notable Notes
• Nutrition, Obesity, Exercise
• Obstetrics and Gynecology
• Occupational Health
• Ophthalmology
• Orthopedics
• Otolaryngology
• Pain Medicine
• Palliative Care
• Pathology and Laboratory Medicine
• Patient Care
• Patient Information
• Performance Improvement
• Performance Measures
• Perioperative Care and Consultation
• Pharmacoeconomics
• Pharmacoepidemiology
• Pharmacogenetics
• Pharmacy and Clinical Pharmacology
• Physical Medicine and Rehabilitation
• Physical Therapy
• Physician Leadership
• Population Health
• Primary Care
• Professional Well-being
• Professionalism
• Psychiatry and Behavioral Health
• Public Health
• Pulmonary Medicine
• Regulatory Agencies
• Reproductive Health
• Research, Methods, Statistics
• Resuscitation
• Rheumatology
• Risk Management
• Scientific Discovery and the Future of Medicine
• Shared Decision Making and Communication
• Sleep Medicine
• Sports Medicine
• Stem Cell Transplantation
• Substance Use and Addiction Medicine
• Surgical Innovation
• Surgical Pearls
• Teachable Moment
• Technology and Finance
• The Art of JAMA
• The Arts and Medicine
• The Rational Clinical Examination
• Tobacco and e-Cigarettes
• Translational Medicine
• Trauma and Injury
• Treatment Adherence
• Ultrasonography
• Users' Guide to the Medical Literature
• Vaccination
• Venous Thromboembolism
• Veterans Health
• Women's Health
• Workflow and Process
• Wound Care, Infection, Healing
• Download PDF
• Share X Facebook Email LinkedIn
• Permissions

Steroid Side Effects

• 1 JAMA , Chicago Illinois
• 2 Midwestern University, Downers Grove, Illinois

Steroid medications, which are prescribed in many different forms for many different conditions, have a multitude of side effects.

Corticosteroid medications—often just called steroids by clinicians and patients—are used to reduce inflammation and inhibit the immune system. They are also associated with many side effects.

Corticosteroid medications are synthetic versions of the human steroid hormone cortisol , which is produced in the adrenal glands. These are different from the synthetic versions of the human steroid hormone testosterone used by some athletes (anabolic steroids) or the synthetic versions of the human steroid hormone estrogen used by some women after menopause (hormone therapy).

Formulations

Steroids can be taken as a tablet for simple rashes or mild asthma attacks or given intravenously for flares of autoimmune diseases such as inflammatory bowel disease or rheumatoid arthritis. To minimize the side effects of oral or intravenous steroids, steroid treatments that act locally were developed. Examples include

Topical application to the skin for conditions like eczema or psoriasis

Nasal inhalation for allergy symptoms

Inhalation into the lungs to control asthma symptoms

Injection into joints to reduce pain and inflammation

Eye drops to reduce swelling after eye surgery

Side Effects

Some patients find taking steroids to be difficult because of side effects; other patients like how steroids make them feel. Side effects are most common with oral or intravenous steroids, but sometimes enough locally directed steroid is absorbed systemically to cause side effects. Life-threatening side effects include

Infection: Steroids are effective in treating autoimmune diseases because they reduce the ability of the immune system to function ( immunosuppression ). Patients taking steroids are not only more susceptible to infections but more likely to have severe or unusual infections. These patients should be aware of their increased risk of infection, and their physicians may recommend additional anti-infective medications.

Adrenal crisis: Cortisol is produced in the adrenal glands. It has many effects throughout the body, including regulating blood pressure. Because steroids are so similar to cortisol, prolonged use of systemic steroids at higher doses can cause the adrenal glands to stop making cortisol. If the systemic steroid is stopped suddenly, this adrenal suppression and resulting lack of steroid can cause a wide range of symptoms, such as dangerously low blood pressure.

Health care practitioners are cautious in prescribing steroids because of the side effects. They prescribe them only when necessary and for as short a time as possible. Local rather than systemic therapy is preferable and prescribed when possible. If a patient needs to stop taking a systemic steroid after taking it for a long time, they are prescribed a gradually reduced dose to give the adrenal glands time to “wake up” and start producing cortisol again. When longer courses of higher-dose systemic steroids are necessary, as in some autoimmune conditions, the patient is monitored closely for side effects.

For More Information

US National Library of Medicine medlineplus.gov/steroids.html

Conflict of Interest Disclosures: None reported.

Source: Zoorob RJ, Cender D. A different look at corticosteroids. Am Fam Physician . 1998;58(2):443-450.

See More About

Grennan D , Wang S. Steroid Side Effects. JAMA. 2019;322(3):282. doi:10.1001/jama.2019.8506

Manage citations:

© 2024

Artificial Intelligence Resource Center

Cardiology in JAMA : Read the Latest

Browse and subscribe to JAMA Network podcasts!

Others Also Liked

• Register for email alerts with links to free full-text articles
• Access PDFs of free articles
• Manage your interests
• Save searches and receive search alerts

• Open access
• Published: 05 October 2022

Real-world effectiveness of steroids in severe COVID-19: a retrospective cohort study

• Wenjuan Wang 1 ,
• Luke B Snell 2 , 3 , 4 ,
• Davide Ferrari 1 ,
• Anna L Goodman 3 ,
• Nicholas M Price 3 ,
• Charles D Wolfe 1 , 4 ,
• Vasa Curcin 1 , 4 ,
• Jonathan D Edgeworth 2 , 3 , 4 &
• Yanzhong Wang 1 , 4  

BMC Infectious Diseases volume  22 , Article number:  776 ( 2022 ) Cite this article

3523 Accesses

2 Citations

1 Altmetric

Metrics details

Introduction

Randomised controlled trials have shown that steroids reduce the risk of dying in patients with severe Coronavirus disease 2019 (COVID-19), whilst many real-world studies have failed to replicate this result. We aim to investigate real-world effectiveness of steroids in severe COVID-19.

Clinical, demographic, and viral genome data extracted from electronic patient record (EPR) was analysed from all SARS-CoV-2 RNA positive patients admitted with severe COVID-19, defined by hypoxia at presentation, between March 13th 2020 and May 27th 2021. Steroid treatment was measured by the number of prescription-days with dexamethasone, hydrocortisone, prednisolone or methylprednisolone. The association between steroid > 3 days treatment and disease outcome was explored using multivariable cox proportional hazards models with adjustment for confounders (including age, gender, ethnicity, co-morbidities and SARS-CoV-2 variant). The outcome was in-hospital mortality.

1100 severe COVID-19 cases were identified having crude hospital mortality of 15.3%. 793/1100 (72.1%) individuals were treated with steroids and 513/1100 (46.6%) received steroid ≤ 3 days. From the multivariate model, steroid > 3 days was associated with decreased hazard of in-hospital mortality (HR: 0.47 (95% CI: 0.31–0.72)).

The protective effect of steroid treatment for severe COVID-19 reported in randomised clinical trials was replicated in this retrospective study of a large real-world cohort.

Peer Review reports

Currently, steroids are the main treatment for severe coronavirus disease 2019 (COVID-19) infection [ 1 ], which has infected over 540million people and caused over 6million deaths worldwide [ 2 ]. The RECOVERY trial [ 3 , 4 ] was the first randomised controlled trial to show that in patients hospitalized with COVID-19, the use of dexamethasone resulted in lower 28-day mortality among those who were receiving either invasive mechanical ventilation or oxygen alone but not among those receiving no respiratory support. Some meta-analyses have shown a benefit of steroids at preventing mortality [ 5 , 6 ] and reducing need for mechanical ventilation [ 6 ]. However, other meta-anlysis from both observational studies and randomised controlled trials have shown conflicting results [ 7 , 8 ].

A guideline was issued by WHO on use of dexamethasone and other corticosteroids (hydrocortisone or prednisone) for treatment of severe and critically unwell COVID-19 patients in September 2020 [ 9 ]. After the RECOVERY trial and WHO guidelines, the use of steroids changed from being used in ICU for some very severe patients, to more consistent use in patients admitted to hospital requiring oxygen. Our objective was to determine whether the effect of steroids on outcomes for severe COVID-19 patients reported in randomised trials is replicated in a large real-world cohort spanning the duration of the pandemic.

Population of interest and setting

Guy’s and St Thomas’ NHS Foundation Trust (GSTT) is a multi-site inner-city healthcare institution providing general and emergency services predominantly to the South London boroughs of Lambeth and Southwark. NHS is the National Health Service in the UK. The acute-admitting site (St Thomas’ Hospital) has an emergency department with a large critical care service. A second hospital site (Guy’s Hospital) provides elective surgery, haemato-oncology, renal transplantation and other specialist services. There are also several community sites providing dialysis, rehabilitation and long-term care. Only COVID-19 cases admitted through the emergency department (ED) during March 13th 2020 and May 27th 2021 were included in this study. Patients dying or being discharged in the first 24h were considered most likely to have reached study endpoint independent of any steroid effect and were excluded from the primary analysis.

SARS-CoV-2 laboratory testing

GSTT has an on-site laboratory providing SARS-CoV-2 testing to all patients and hospital care workers (HCW). The policies and technologies employed for SARS-CoV-2 testing changed over time based on national and local screening guidance and improvements in diagnostics. Our laboratory began testing on 13th March 2020 with initial capacity for around 150 tests per day, before increasing to around 500 tests per day in late April during wave one, and up to 1000 tests per day during the second wave.

Assays used for the detection of SARS-CoV-2 RNA include PCR testing using Aus Diagnostics or by the Hologic Aptima SARS-CoV-2 Assay. Testing commenced during the first wave on 13th March 2020 limited to cases requiring admission or inpatients who had symptoms of fever or cough, as per national recommendation; guidance suggested cases who did not require admission should not be tested. Cases without laboratory confirmation of SARS-CoV-2 infection were not included.

Definitions

Cases were identified by the first positive SARS-CoV-2 RNA test. The severe cases were measured by hypoxia upon admission to hospital. Cases were taken to be hypoxic if on admission they had oxygen saturations of < 94%, if they were recorded as requiring supplemental oxygen, or if the fraction of inspired oxygen was recorded as being greater than 0.21.

Determination of SARS-CoV-2 lineage

Whole genome sequencing of residual samples from SARS-CoV-2 cases was performed using GridION (Oxford Nanopore Technology), using version 3 of the ARTIC protocol [ 10 ] and bioinformatics pipeline [ 11 ]. Samples were selected for sequencing if the corrected CT value was 33 or below, or the Hologic Aptima assay was above 1000 relative light units (RLU). During the first wave sequencing occurred between March 1st − 31st, whilst sequencing restarted in November 2020 and is ongoing. Lineage determination was performed using updated versions of pangolin 2.0 [ 12 ]. Samples were regarded as successfully sequenced if over 50% of the genome was recovered and if lineage assignment by pangolin was given with at least 50% confidence.

Data sources, extraction and integration

Clinical, laboratory and demographic data for all cases with a laboratory reported SARS-CoV-2 PCR RNA test on nose and throat swabs or lower respiratory tract specimens were extracted from hospital electronic patient record (EPR) data sources using records closest to the test date (DXC Technology’s i.CM EPR, Philips IntelliVue Clinical Information Portfolio (ICIP) Critical Care, DXC Technology’s MedChart, e-Noting and Citrix Remote PACS - Sectra). Data was linked to the Index of Multiple Deprivation (IMD), with 1 denoting the least deprived areas, and 5 the most deprived ones. Age and sex were extracted from EPR. Self-reported ethnicity of cases was stratified to be White, BAME (Black, Asian and Minority Ethnic) and Unknown according to the 18 ONS categories of White (British, Irish, Gypsy and White-Other), Black (African, Caribbean, and Black-Other), Asian (Bangladeshi, Chinese, Indian, Pakistan, and Asian-Other), and Mixed/Other.

Comorbidities, medication history, and medicine data were extracted from the EPR and e-Noting using structured queries with corresponding dictionaries. Comorbidities were extracted from any of the databases covering the pathway of the cases from arrival in accident and emergency through inpatient general ward and critical care unit, where applicable, to hospital discharge or death. If a comorbidity was not recorded, we assume that it was not present. Cases were characterised as having/not having a past medical history of hypertension, cardiovascular disease (stroke, transient ischaemic attack, atrial fibrillation, congestive heart failure, ischaemic heart disease, peripheral artery disease or atherosclerotic disease), diabetes mellitus, chronic kidney disease, chronic respiratory disease (chronic obstructive pulmonary disease, asthma, bronchiectasis or pulmonary fibrosis) and neoplastic disease (solid tumours, haematological neoplasias or metastatic disease). Additionally, checks on free text data were performed by a cardiovascular clinician to ensure the information was accurate.

Steroid treatment was measured by number of prescription-days with dexamethasone, hydrocortisone, prednisolone or methylprednisolone. Duration of treatment with steroids was calculated as cumulative days throughout first hospital admission after the first SARS-CoV-2 PCR positive test through to discharge or death during that admission. Analysis for lengths of steroid use were conducted in multivariate model with steroid use ≤ 3 days versus steroid use > 3 days. The cut-off for the steroid treatment days were chosen according to the interquartile range of steroid-days (3 to 10 days) in RECOVERY trial. Sensitivity analysis was conducted with continuous steroid days as the variable input in the Cox proportional hazards model.

The outcome was all-cause in-hospital mortality (WHO-COVID-19 Outcomes Scale 8), with patients still hospitalised at the end of the cohort considered censored.

Statistical analysis

The general statistics were summarised with mean and standard deviation (SD) for continuous variables if the distribution is normal and median and interquartile range (IQR) if the distribution is non-normal. Count and percentages were used for categorical variables. For the comparisons of the cohort statistics with different lengths of steroid use days (< 3 days vs. ≥ 3 days), Kruskal-Walllis test was used for continuous variables and Chi-squared test for categorical variables. The reference significant level was set to be p < 0.05.

Cox proportional hazards models were used for time-to-event survival analysis in which the time was starting from hospital admission and events as the defined outcomes. Adjusted hazards ratios for the primary and secondary outcomes using Cox proportional hazards models were presented. The adjusted variables used in the model were selected via literature review [ 4 ] and clinical experts (Additional file Table A). Age, sex, Body Mass Index (BMI) > 30kg/m 2 , hypertension, cardiovascular disease, diabetes, respiratory disease, chronic kidney disease, sequenced SARS-CoV-2 variant and medications including steroids and tocilizumab/sarilumab were used as pre-defined covariates to adjust in multivariable models. As the distribution of steroid days is right skewed (steroid days ≥ 0), before modelling, the continuous steroid days were transformed with the log of steroid days plus one (log(steroid days + 1)). Missing values of the variant, BMI and ethnicity were imputed as a new category and cases with missing values in IMD were discarded. There were no missing values in other adjusted variables.

Data management was performed using SQL databases, with analysis carried out on the secure King’s Health Partners (KHP) Rosalind high-performance computer infrastructure [ 5 ] running Jupyter Notebook 6.0.3, R 3.6.3 and Python 3.7.6.

Description of population, steroid use and outcomes

1120 patients were identified with hypoxia on admission of which 1100 were included in the analysis after removal of 20 cases that stayed for less than 24h after admission. 23 cases with missing data in the IMD variable were imputed with median. In-hospital mortality of the whole cohort was 15.0% (Table 1 ). 793/1100 (72.1%) individuals were treated with steroids (> 0 days) and the median of steroid days was 6.0, IQR [3,9]. Before the WHO guideline, only 96/366 (26.2%) patients were treated with steroids compared to 697/734 (95%) after the WHO guideline (Table 2 ; Fig. 1 ). Overall, steroids were used for a median of 0 days [IQR: 0.0,1.0] before the WHO guideline, and 5.5 days [IQR: 3.0,9.0] after WHO guideline. Before the WHO guideline, 17.2% patients had more than 3 days steroids and 7.9% more than 10 days, whilst after the WHO guidelines 71.4% had more than 3 days and 14.3% had more than 10 days (Table 2 ).

Hospital mortality was 20.8% amongst 307 patients who did not receive steroids and 12.7% amongst 793 patients who received steroids. For patients who received ≤ 3 days of steroids, 17.2% died in hospital compared to 13.1% who died in hospital for patients who received > 3days of steroids. A higher mortality rate for patients who received > 10 days of steroids (24.6%) compared to patients who received ≤ 10 days of steroids (13.7%) was observed (Table 1 ).

Comparing patient characteristics between patients who had ≤ 3 days of steroids and who had > 3 days steroids (Table 1 ), we found that patients who had steroids for > 3 days were less likely to be of BAME ethnicity (38.2% vs. 44.6%, p = 0.035), had more obesity (37.6% vs. 30.2%, p = 0.003), had more hypertension (39.4% vs. 32.4%, p = 0.019), a higher proportion with solid organ transplatation (3.6% vs. 1.0%, p = 0.008), higher use of tocilizumab (2.0% vs. 0%, p = 0.003), and had much more Alpha variant due to the emergence of Alpha in wave two (26.9% vs. 10.3%).

Frequency of steroid treatment-days for patients admitted before and after WHO guideline

Cox proportional hazard model for the outcome of mortality

The Cox proportional hazard models showed significant protective effect of steroids used for more than 3 days compared to less steroids (HR: 0.47 (95% CI: 0.31–0.72)) for mortality. The protective effect of steroids was consistent when using steroids as a continuous variable (HR: 0.86 (95% CI: 0.76–0.96)) (Additional file Table B).

Other variables (Table 3 ) including age, cardiovascular co-morbidity, and human immunodeficiency virus (HIV) infection had significant associations with death. The remaining variables including sex, ethnicity, IMD, hypertension, diabetes, respiratory disease, cancer, kidney disease and transplantation, Alpha variant, obesity (BMI > 30), and tocilizumab administration were not significantly associated with the outcome in the multivariable analysis.

This study provides evidence for real-world effectiveness of steroids in reducing death amongst severe COVID-19 patients. The protective effect-size of treatment with steroids was similar to that reported in the RECOVERY clinical trial [ 3 ] for a comparable group of patients defined by receipt of oxygen therapy. This adds to the evidence base for a clinical benefit of steroid treatment in COVID-19.

We adjusted for potential confounders (e.g. age, sex, ethnicity, comorbidities, BMI and IMD) as well as the characteristics of the virus (Alpha variant) and another treatment (tocilizumab) with the effect of steroids remaining statistically significant. Undoubtedly, we are unable to adjust for all confounders, including the vaccination status, other co-treatments and improvements introduced around the time of steroids e.g. thromboprophylaxis and proning which might compromise the practical use of the study findings even though the protective effects of steroids were significantly protective in the model. Vaccination could be a big confounder which was started from December 2020 and by the end of the study (17th May 2021), most of the adults had received one dose of vaccination. Regarding other co-treatments, during most of the study period, other drug therapeutics were not routinely deployed, and the effect size of newer treatments like tocilizumab were much less than steroids in clinical trials. No other SARS-CoV-2 variants that have been associated with altered severity of disease were circulating in our population during the study period.

It is notable the study was done in an institution that had good overall comparative NHS outcomes and an standardized mortality ratio (SMR) of 0.5 in ICU patients, with guidelines and practice recommending longer courses of steroids for severe patients. Over 80% of the > 10 steroid-days group were treated deliberately with long steroids and the remaining were on long term steroids as therapeutic immunomodulation for other conditions. Whether longer course of steroids has an additional benefit is not known.

Longer durations of steroids have not been systematically studied and might increase the risk/rate of adverse events, including delayed viral clearance [ 13 ]. Some studies are identifying other potential adverse events associated with steroids such as invasive mould infections including aspergillosis and mucormycosis [ 14 ], with work ongoing to assess the effect of steroids on risk of bloodstream infection [ 15 ].

In this study we investigated the association of steroid days with outcomes, however our analyses are agnostic to the dose of steroids used. There may be reasons why duration of steroid treatment mediates effects on outcomes independently of cumulative dose, for instance if a sustained period of immunosuppression is needed to prevent immune-mediated inflammation. In addition, as this study is retrospective and observational the link between steroids and the outcome is only an association and causality should not be inferred.

Many other studies on the real-world effectiveness of steroids have failed to reproduce the findings of clinical trials. Partly, this may be due to small sample size, heterogeneity of treatment and non-treatment groups, and incorrectly testing associations on individuals not expected to benefit, i.e. cases without evidence of hypoxia. Our study benefits from a wide time period for inclusion, allowing us to capture the changing treatment landscape before steroid use in COVID-19 was standardised in line with national and international guidelines. Additionally our adjustment accounts for many baseline variables which have previously been associated with severe outcomes. The validity of our analyses is supported by the findings that variables previously associated with severity, such as age and cardiovascular comorbidity retain significance in our modelling.

Other studies have found the Alpha variant of SARS-CoV-2 to be associated with severe disease, especially mortality [ 16 , 17 , 18 ] and hypoxia on admission [ 19 ]. However, another study in hospitalised patients did not find such an association [ 20 ]. To our knowledge, no studies on the severity of the alpha variant adjusted for newly introduced therapeutics. Interestingly, the association of alpha variant with severe disease as measured by mortality was not found in this study. This is in contrast to our initial findings in the same dataset that the Alpha variant was associated with severity as measured by hypoxia on admission [ 19 ]. It may be that severity of the alpha variant is ameliorated by efficacious treatment of hospitalised patients. This may be especially true as during the second wave steroid treatment had been introduced and standardised as the alpha variant emerged. This would also explain the disparity between findings of other published studies, with the only other study of variant status and death in hospitalised patients not finding an association.

Limitations of this study might include potential bias for patients who did not have a chance to receive steroids or received very short steroids because they were very severe and died soon after admission. This is an issue that is intractable with retrospective study, and we attempt to address this by excluding those who died in the first 24h after admission. Another limitation is that the choice of cut-offs for the steroid treatment days were chosen according to data from RECOVERY trial, our local recommendations, and WHO guidelines rather than pharmacological effect of steroids treatment in COVID-19.

The protective effect of steroids in severe COVID-19 seen in our cohort is similar to that seen in clinical trials, confirming the real world effectiveness.

Data Availability

The data that support the findings of this study are available from Guy’s and St Thomas’ NHS Foundation Trust (GSTT) but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of GSTT.

Abbreviations

Intensive Care Unit.

Coronavirus Disease 2019.

Guy’s and St Thomas’ NHS Foundation Trust.

Electronic Patient Record.

Index of Multiple Deprivation.

Standard Deviation.

Interquartile Range.

Body Mass Index.

Human Immunodeficiency Virus.

Hazard Ratio.

Bhimraj A, Morgan RL, Shumaker AH, Lavergne V, Baden L, Cheng VC, Edwards KM, Gandhi R, Gallagher J, Muller WJ, O’Horo JC, Shoham S, Murad MH, Mustafa RA, Sultan S, Falck-Ytter Y. Infectious Diseases Society of America Guidelines on the Treatment and Management of Patients with COVID-19. Infectious Diseases Society of America 2022; Version 9.0.1. Available at https://www.idsociety.org/practice-guideline/covid-19-guideline-treatment-and-management/ .

WHO emergency response team. Weekly epidemiological update on COVID-19–17 August 2022, Edition 105, https://www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-19---17-august-2022 .

The RECOVERY Collaborative Group. Dexamethasone in Hospitalized Patients with Covid-19 — Preliminary Report. N Engl J Med Published online July. 2020;17:NEJMoa2021436. https://doi.org/10.1056/NEJMoa2021436 .

Article   Google Scholar  

RECOVERY Collaborative Group. Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial. Lancet Lond Engl. 2021;397(10285):1637–45. https://doi.org/10.1016/S0140-6736(21)00676-0 .

The WHO Rapid Evidence Appraisal for COVID-19 Therapies (REACT) Working Group. Association Between Administration of Systemic Corticosteroids and Mortality Among Critically Ill Patients With COVID-19: A Meta-analysis. JAMA. 2020;324(13):1330–41. https://doi.org/10.1001/jama.2020.17023 .

Article   CAS   Google Scholar  

van Paassen J, Vos JS, Hoekstra EM, Neumann KMI, Boot PC, Arbous SM. Corticosteroid use in COVID-19 patients: a systematic review and meta-analysis on clinical outcomes. Crit Care. 2020;24(1):696. https://doi.org/10.1186/s13054-020-03400-9 .

Article   PubMed   PubMed Central   Google Scholar  

Sahilu T, Sheleme T, Melaku T. Severity and Mortality Associated with Steroid Use among Patients with COVID-19: A Systematic Review and Meta-Analysis. Interdiscip Perspect Infect Dis. 2021;2021:6650469. https://doi.org/10.1155/2021/6650469 .

Article   CAS   PubMed   PubMed Central   Google Scholar  

Yang Z, Liu J, Zhou Y, Zhao X, Zhao Q, Liu J. The effect of corticosteroid treatment on patients with coronavirus infection: a systematic review and meta-analysis. J Infect. 2020;81(1):e13–20. https://doi.org/10.1016/j.jinf.2020.03.062 .

Corticosteroids for COVID-19. Accessed August 17. 2021. https://www.who.int/publications-detail-redirect/WHO-2019-nCoV-Corticosteroids-2020.1 .

Quick J. nCoV-2019 sequencing protocol. Published online January 22, 2020. https://doi.org/10.17504/protocols.io.bbmuik6w .

Artic Network. Accessed August 17. 2021. https://artic.network/ncov-2019/ncov2019-bioinformatics-sop.html .

Pangolin CoV-lineages. 2021. Accessed August 17, 2021. https://github.com/cov-lineages/pangolin .

Yu WC, Hui DSC, Chan-Yeung M. Antiviral agents and corticosteroids in the treatment of severe acute respiratory syndrome (SARS). Thorax. 2004;59(8):643–5. https://doi.org/10.1136/thx.2003.017665 .

Fernandes M, Brábek J. COVID-19, corticosteroids and public health: a reappraisal. Public Health. 2021;197:48–55. https://doi.org/10.1016/j.puhe.2021.05.028 .

Article   CAS   PubMed   Google Scholar  

Snell LB, Irwin J, Buckingham C, et al. Increasing Rates of Intensive Care Unit Bloodstream Infections During the Second COVID-19 Pandemic Wave, Particularly Primary Endogenous Enterococcus Faecium, with High Crude Mortality and Associated with Introduction of Immunomodulatory Therapy . Social Science Research Network; 2021. https://doi.org/10.2139/ssrn.3895049 .

Patone M, Thomas K, Hatch R, et al. Mortality and critical care unit admission associated with the SARS-CoV-2 lineage B.1.1.7 in England: an observational cohort study. Lancet Infect Dis Published online June 23, 2021. https://doi.org/10.1016/S1473-3099(21)00318-2 .

Patone M, Thomas K, Hatch R, et al. Analysis of Severe Outcomes Associated with the SARS-CoV-2 Variant of Concern 202012/01 in England Using ICNARC Case Mix Programme and QResearch Databases .; 2021:2021.03.11.21253364.

Davies NG, Jarvis CI, Edmunds WJ, Jewell NP, Diaz-Ordaz K, Keogh RH. Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7. Nature. 2021;593(7858):270–4. https://doi.org/10.1038/s41586-021-03426-1 .

Snell L, Wang W, Alcolea-Medina A, et al. Descriptive comparison of admission characteristics between pandemic waves and multivariable analysis of the association of the Alpha variant (B.1.1.7 lineage) of SARS-CoV-2 with disease severity in inner London. BMJ Open. 2022;12:e055474. https://doi.org/10.1136/bmjopen-2021-055474 .

Article   PubMed   Google Scholar  

Frampton D, Rampling T, Cross A, et al. Genomic characteristics and clinical effect of the emergent SARS-CoV-2 B.1.1.7 lineage in London, UK: a whole-genome sequencing and hospital-based cohort study. Lancet Infect Dis Published online April 12, 2021. https://doi.org/10.1016/S1473-3099(21)00170-5 .

Download references

Acknowledgements

The authors acknowledge use of the research computing facility at King’s College London, Rosalind ( https://rosalind.kcl.ac.uk ), which is delivered in partnership with the National Institute for Health Research (NIHR) Biomedical Research Centres at South London & Maudsley and Guy’s & St. Thomas’ NHS Foundation Trusts and NIHR Applied Research Collaboration (ARC) South London at King’s College Hospital (KCH) NHS Foundation Trust and King’s College London, and part-funded by capital equipment grants from the Maudsley Charity (award 980) and Guy’s & St. Thomas’ Charity (TR130505). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, King’s College London, or the Department of Health and Social Care.

This work was supported by the King’s Together Multi and Interdisciplinary Research Scheme (Wellcome Trust Revenue Retention Award). LBS, and YW are supported by the National Institute for Health Research (NIHR) Biomedical Research Centre programme of Infection and Immunity (RJ112/N027) based at Guy’s and St Thomas’ National Health Service NHS) Foundation Trust and King’s College London and was funded by the National Institute for Health Research (NIHR) [Programme Grants for Applied Research (NIHR202339)]. This work was also supported by The Health Foundation and the Guy’s and St Thomas’ Charity. COG-UK is supported by funding from the Medical Research Council (MRC) part of UK Research & Innovation (UKRI), the National Institute of Health Research (NIHR) and Genome Research Limited, operating as the Wellcome Sanger Institute. VC is supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ National Health Service Foundation Trust and King’s College London, and the Public Health and Multi-morbidity Theme of the National Institute for Health Research’s Applied Research Collaboration (ARC) South London. VC is also supported by the EPSRC CONSULT grant (EP/P010105/1). VC is partly funded by the EPSRC project Consult: Collaborative Mobile Decision Support for Managing Multiple Morbidities, EP/P000339/1. LBS receives funding from the Medical Research Council (MR/W025140/1). DF is also partly funded by DRIVE-Health, KCL funded Centre for Doctoral Training (CDT) in Data-Driven Health.

The funding body did not participate in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.

Author information

Authors and affiliations.

School of Population Health and Environmental Sciences, King’s College London, London, UK

Wenjuan Wang, Davide Ferrari, Charles D Wolfe, Vasa Curcin & Yanzhong Wang

Centre for Clinical Infection and Diagnostics Research, School of Immunology and Microbial Sciences, King’s College London, London, UK

Luke B Snell & Jonathan D Edgeworth

Department of Infectious Diseases, Guy’s and St Thomas’ NHS Foundation Trust, London, UK

Luke B Snell, Anna L Goodman, Nicholas M Price & Jonathan D Edgeworth

NIHR Biomedical Research Centre, Guy’s and St Thomas’ NHS Foundation Trust, London, UK

Luke B Snell, Charles D Wolfe, Vasa Curcin, Jonathan D Edgeworth & Yanzhong Wang

You can also search for this author in PubMed   Google Scholar

Contributions

WW and LBS contributed to conceptualisation, data curation, methodology, formal analysis, and writing – original draft and editing. DF performed data curation and visualisation. ALG and NMP provided data interpretation and review&editing. VC performed supervision, funding acquision, project administration, and review&editing. JDE and YW performed conceptualisation, supervision, funding acquision, methodology, project administration, data interpretation, and review&editing. All authors have read and approved the manuscript.

Corresponding author

Correspondence to Wenjuan Wang .

Ethics declarations

Ethics approval and consent to participate.

Ethical approval for data informatics was granted by The London Bromley Research Ethics Committee (reference (20/HRA/1871)) to the King’s Health Partners Data Analytics and Modelling COVID-19 Group to collect clinically relevant data points from patient’s electronic health records.

Whole genome sequencing of residual viral isolates was conducted under the COVID-19 Genomics UK (COG-UK) consortium study protocol, which was approved by the Public Health England Research Ethics and Governance Group (reference: R&D NR0195).

All methods were carried out in accordance with relevant guidelines and regulations. Patient consent was waived by The London Bromley Research Ethics Committee (reference (20/HRA/1871)).

Consent for publication

Not applicable.

Competing interests

Additional information, publisher’s note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Jonathan D Edgeworth and Yanzhong Wang contributed equally and are joint senior authors.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Rights and permissions.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/ ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article.

Wang, W., Snell, L.B., Ferrari, D. et al. Real-world effectiveness of steroids in severe COVID-19: a retrospective cohort study. BMC Infect Dis 22 , 776 (2022). https://doi.org/10.1186/s12879-022-07750-3

Download citation

Received : 27 June 2022

Accepted : 06 September 2022

Published : 05 October 2022

DOI : https://doi.org/10.1186/s12879-022-07750-3

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Retrospective cohort study

BMC Infectious Diseases

ISSN: 1471-2334

• Submission enquiries: [email protected]
• General enquiries: [email protected]

• Search Menu
• Advance articles
• Author Guidelines
• Open Access
• About Integrative and Comparative Biology
• About the Society for Integrative and Comparative Biology
• Editorial Board
• Advertising and Corporate Services
• Journals Career Network
• Self-Archiving Policy
• Dispatch Dates
• Journals on Oxford Academic
• Books on Oxford Academic

Article Contents

Introduction, implications of studies of humans for studies of nonhuman animals, conclusions, acknowledgments.

• < Previous

Steroid use and human performance: Lessons for integrative biologists

From the symposium “Hormonal Regulation of Whole-Animal Performance: Implications for Selection” presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3–7, 2009, at Boston, Massachusetts.

2 Present address: Department of Biology, University of South Dakota, Vermillion, SD 57069, USA

• Article contents
• Figures & tables
• Supplementary Data

Jerry F. Husak, Duncan J. Irschick, Steroid use and human performance: Lessons for integrative biologists, Integrative and Comparative Biology , Volume 49, Issue 4, October 2009, Pages 354–364, https://doi.org/10.1093/icb/icp015

• Permissions Icon Permissions

While recent studies have begun to address how hormones mediate whole-animal performance traits, the field conspicuously lags behind research conducted on humans. Recent studies of human steroid use have revealed that steroid use increases muscle cross-sectional area and mass, largely due to increases in protein synthesis, and muscle fiber hypertrophy attributable to an increased number of satellite cells and myonuclei per unit area. These biochemical and cellular effects on skeletal muscle morphology translate into increased power and work during weight-lifting and enhanced performance in burst, sprinting activities. However, there are no unequivocal data that human steroid use enhances endurance performance or muscle fatigability or recovery. The effects of steroids on human morphology and performance are in general consistent with results found for nonhuman animals, though there are notable discrepancies. However, some of the discrepancies may be due to a paucity of comparative data on how testosterone affects muscle physiology and subsequent performance across different regions of the body and across vertebrate taxa. Therefore, we advocate more research on the basic relationships among hormones, morphology, and performance. Based on results from human studies, we recommend that integrative biologists interested in studying hormone regulation of performance should take into account training, timing of administration, and dosage administered when designing experiments or field studies. We also argue that more information is needed on the long-term effects of hormone manipulation on performance and fitness.

One of the most widely discussed and controversial arenas of human performance concerns the use of steroid supplements to enhance athletic ability for a variety of sports, ranging from bicycling to baseball. There is strong evidence that human athletes have attempted to enhance their athletic performance using steroids since the 1950s, but whether, and in which sports, steroids are actually effective remains controversial (reviewed by Ryan 1981 ; George 2003 ; Hartgens and Kuipers 2004 ). In general, steroids used by athletes encompass a wide variety of forms of the androgen testosterone (George 2003 ), and most seem to have the classical androgenic and anabolic effects on men, although steroid use by women cannot be ignored (Malarkey et al. 1991 ; Gruber and Pope 2000 ). Alternative forms of testosterone (e.g., testosterone enanthate, methandrostenolone) are typically used by those desiring enhanced performance because ingested or injected testosterone is quickly metabolized into inactive forms (Wilson 1988 ). Thus, studies of humans that we cite involve testosterone derivatives. Early studies of the effects of steroids on human performance, however, had major flaws in design, such as lack of control groups and a double-blind procedure, the presence of confounding factors (e.g., differences in level of exercise and in motivation), and inappropriate statistical techniques (reviewed by Bhasin et al. 2001 ; George 2003 ). These problems left open for many years the question of whether, and in what capacity, steroids actually enhance athletic performance, until more recent studies conclusively showed significant effects of steroids.

The topic of steroid effects on human athletic performance is germane to an emerging field of research investigating hormonal effects on animals’ performance (e.g., sprint speed, endurance capacity, bite-force capacity) (Husak et al. 2009a ), as testosterone may exert general effects on performance across widely divergent vertebrate taxa. Our goal in this review is to interpret the effects of steroids on human performance in this broader context of hormonal effects across a wider range of taxa. We are particularly interested in drawing lessons and potential avenues of research for animal biologists from published research on humans. We have performed a selective review of studies examining how humans' use of steroids affects skeletal muscle physiology and subsequent athletic performance. While studies of performance on nonhumans have dealt extensively with the effects of morphological traits on performance and the impact of performance on individual fitness (Arnold 1983 ; Garland and Losos 1994 ; Irschick and Garland 2001 ; Irschick et al. 2007 , 2008 ; Husak et al. 2009a ), there has been relatively little synthetic discussion of how hormones affect performance in non-human animals. We also point the reader towards several recent reviews of steroid use and performance by humans for details not discussed in our review (Bhasin et al. 2001 ; George 2003 ; Hartgens and Kuipers 2004 ).

General effects of testosterone on the phenotype of males

The development of primary and secondary sexual characteristics is stimulated by testosterone in vertebrate males, and these effects can be either organizational or activational in nature (Norris 1997 ; Hadley 2000 ). Organizational effects tend to occur early in development, and during a critical window of time, thereby resulting in permanent effects. On the other hand, activational effects occur in adults, and the effects are typically temporary (Arnold and Breedlove 1985 ). The hypothalamus stimulates production of gonadotropin-releasing hormone, which in turn stimulates production of luetenizing hormone in the anterior pituitary. Luetenizing hormone then stimulates production of testosterone in the Leydig cells of the testes. Testosterone then circulates throughout the body where it exerts effects on multiple target tissues that have the appropriate receptors or appropriate enzymes (e.g., aromatase or 5α-reductase) to convert testosterone for binding to other types of receptors (Kicman 2008 ). The widespread effects of circulating levels of testosterone on aggression, secondary sexual traits, and growth of skeletal muscle in males of many vertebrate species are well-documented (Marler and Moore 1988 ; Wingfield et al. 1990 ; Ketterson and Nolan 1999 ; Sinervo et al. 2000 ; Ketterson et al. 2001 ; Oliveira 2004 ; Adkins-Regan 2005 ; Hau 2007 ; contributions in this issue). In particular, production of testosterone by males has been linked with the expression of color and behavioral display signals, as well as aggression (Marler and Moore 1988 ; Kimball and Ligon 1999 ; Hews and Quinn 2003 ; Adkins-Regan 2005 ; Cox et al. 2008 ) and increased growth (Fennell and Scanes 1992 ; Borski et al. 1996 ; Cox and John-Alder 2005 ), although this latter effect may depend on specific selective pressures on males (Cox and John-Alder 2005 ).

Effects of testosterone on the physiology of human skeletal muscle

Testosterone has multiple effects on skeletal muscle at the biochemical and cellular levels, but the direct cause-and-effect relationships among these effects are still unclear (Sinha-Hikim 2002 ; Hartgens and Kuipers 2004 ). The studies that we discuss here, and throughout the paper are from experiments or correlative studies conducted on adult individuals such that the effects seen are activational in nature, causing rather rapid changes to the phenotype. Increased testosterone causes increased protein synthesis by muscle cells (Griggs et al. 1989 ; Kadi et al. 1999 ; Hartgens and Kuipers 2004 ), which is necessary for anabolic effects and an increase in lean muscle mass. Sinha-Hikim et al. ( 2002 ) found a dose-dependent increase in the mean number of myonuclei found in skeletal muscle fibers ( vastus lateralis muscle) with testosterone supplementation, as well as in the number of myonuclei per fiber (see also Eriksson et al. 2005 ). This increase was also associated with an increase in the number of satellite cells in the muscle tissue (but see Eriksson et al. 2005 ). Satellite cells are progenitor cells found external to muscle fibers that are incorporated into fibers and promote repair and growth of the muscle (Kadi and Thornell 2000 ; Reimann et al. 2000 ). However, the mechanism by which testosterone causes an increase in the number of satellite cells is unknown and could be due to testosterone (1) promoting cell division of satellite cells, (2) inhibiting apoptosis of satellite cells, or (3) causing differentiation of stem cells into satellite cells (Sinha-Hikim 2002 ). In any case, the functional implications for these findings are clear. More satellite cells likely result in more myonuclei per fiber, which, combined with increased protein synthesis, contribute to increases in muscle growth via an increased number and hypertrophy of muscle fibers (Kadi 2000 ; Kadi and Thornell 2000 ).

Testosterone also appears to cause a dose-dependent increase in the cross-sectional area of muscle fibers, although details about which types of fibers are affected and where in the body this occurs remains equivocal. Testosterone may increase the cross-sectional area of both type I (oxidative “slow twitch”) and type II (glycolytic “fast twitch”) fibers simultaneously after administration (Sinha-Hikim 2002 ; Eriksson et al. 2005 ), but other studies have shown greater increases in type I than in type II fibers (Hartgens et al. 1996 ; Kadi et al. 1999 ; also in growing rats, Ustunelet al. 2003 ), increased size in only type I fibers (Alén et al. 1984 ; Kuipers et al. 1991 , 1993 ), or increased size in only type II fibers (Hartgens et al. 2002 ). These mixed results are intriguing, because they suggest that different parts of the body, and, hence, different performance traits, may be affected differently by elevated testosterone levels. The likely mechanism for these differences is variation in density of receptors within the myonuclei of muscle fibers in different regions of the body (Kadi 2000 ; Kadi et al. 2000 ). An alternative hypothesis is that different types of fiber have differing relationships between the number of internal myonuclei and muscle cross-sectional area during hypertrophy (Bruusgaard et al. 2003 ). That is, some types of fibers may have internal myonuclei that can serve larger “nuclear domains” than can other types of fibers (reviewed by Gundersen and Bruusgaard 2008 ). If either of these hypothesized mechanisms is correct, then circulating levels of testosterone may only explain a portion of inter-individual (or interspecific) variation in performance. Testosterone may also stimulate changes in the proportions of types of fibers in muscles (Holmang et al. 1990 ; Pette and Staron 1997 ), although evidence for this effect in humans is mixed. For example, Sinha-Hikim et al. ( 2002 ) did not observe a change in the proportions of type I and type II fibers after administration of testosterone.

Changes in lower-level traits (e.g., protein synthesis, number of satellite cells, cross sectional area of muscle fibers) after testosterone supplementation, as described above, thus, result in changes at the whole-muscle level and explain many of the classic effects of testosterone that are desired by humans using steroids. That is, increasing testosterone via steroid use increases body weight, lean body mass, as well as cross-sectional area, circumference, and mass of individual muscles (i.e., “body dimensions”); however, there are numerous studies with contradictory results, finding no change in one, or all, of these traits, depending on the drug used, the dose taken, and the duration of use (reviewed by Bhasin et al. 2001 ; Hartgens and Kuipers 2004 ). The finding that testosterone can change muscle physiology and increase whole-muscle size and/or body mass is consistent with results in nonhuman animals. For example, testosterone implants increased size and number of fibers in the sonic muscles of male plainfin midshipman fish ( Porichthys notatus ) (Brantley et al. 1993 ). Similarly, testosterone supplementation increased muscle mass and changed contractile properties of trunk muscles of male grey treefrogs ( Hyla chrysoscelis ) (Girgenrath and Marsh 2003) and of forelimb muscles of male frogs ( Xenopus laevis , Regnier and Herrera 1993 ; Rana pipiens , Sidor and Blackburn 1998 ).

Effects of testosterone on humans’ performance

Whether steroids actually enhance performance of athletes was a subject of great controversy throughout the 1980s and 1990s (Ryan 1981 ; Haupt and Rovere 1984 ; Cowart 1987 ; Wilson 1988 ; Elashoff et al. 1991 ; Strauss and Yesalis 1991 ; Hartgens and Kuipers 2004 ), largely due to flaws in design of early studies (see above). However, the past decade has seen a surge in more carefully designed studies that have convincingly tested whether, all else equal, steroids increase performance. Hartgens and Kuipers ( 2004 ) found that 21 out of 29 studies they reviewed found an increase in humans’ strength after steroid use, with improvements in strength ranging from 5% to 20%. Storer et al. ( 2003 ) found that testosterone caused a dose-dependent increase in maximal voluntary strength of the leg (i.e., amount of weight lifted in a leg press), as well as in leg power (i.e., the rate of force generation). They further tested whether increased muscle strength was due simply to increased muscle mass or to changes in the contractile quality of muscle affected by testosterone, but they found no change in specific tension, or in the amount of force generated per unit volume of muscle. This latter result suggests that, at least for leg-press performance, testosterone increases strength by increasing muscle mass and not by changing contractile properties. Rogerson et al. ( 2007 ) found that supraphysiological doses of testosterone increased maximal voluntary strength during bench presses (see also Giorgi et al. 1999 ) and increased output of work and output of power during cycle sprinting compared to placebo control subjects. Thus, “burst” or “sprint” performance traits appear to be enhanced by increased testosterone, and this is in general agreement with studies of nonhuman animals (John-Alder et al. 1996 , 1997 ; Klukowski et al. 1998 ; Husak et al. 2007 ). For example, experimentally elevated levels of testosterone caused increased sprint speed, relative to sham-implanted individuals, in northern fence lizards ( Sceloporus undulatus ) (Klukowski et al. 1998 ). These findings contrast with results for endurance events, in which no increase in performance has been detected experimentally in humans (reviewed in George 2003 ; Hartgens and Kuipers 2004 ). The finding that endurance by humans is not enhanced by testosterone is unexpected since testosterone may increase hemoglobin concentrations and hematocrit (Alén 1985 , but see Hartgens and Kuipers 2004 ) and exogenous testosterone increases endurance in rats (Tamaki et al. 2001 ) and male side-blotched lizards ( Uta stansburiana ) (Sinervo et al. 2000 ). More studies of the effects of increased testosterone on endurance would help to better clarify these seemingly paradoxical findings. One possibility that might explain species’ differences in endurance is the relative proportion of type I fibers available for enhancement, which likely varies across species (Bonine et al. 2005 ), although this hypothesis needs explicit testing. Steroid use does not seem to consistently enhance recovery time after strenuous exercise (reviewed in Hartgens and Kuipers 2004 ), although it may in non-human animals (Tamaki et al. 2001 ). Storer et al. ( 2003 ) also found no change in fatigability (i.e., the ability of a muscle to persist in performing a task) of muscle during exercise, which is consistent with other studies (George 2003 ).

One of the problems in early studies of steroid effects was that the participants’ history of training and exercise while taking steroids was not taken into account or controlled (Bhasin et al. 2001 ; George 2003 ; Hartgens and Kuipers 2004 ). Recent studies have shown that the presence or absence of exercise training during testosterone supplementation can have a marked impact on how much performance is enhanced, thus complicating results when training is not controlled. Bhasin et al. ( 2001 ) reviewed several examples of such results. They pointed out that testosterone supplementation alone may increase strength from baseline levels, but so will exercise alone with a placebo, such that strength levels with exercise alone are comparable to those with testosterone addition alone (Bhasin et al. 1996 ). Testosterone supplementation while undergoing exercise training typically has the greatest increase in strength compared to exercise only or testosterone only (Bhasin et al. 1996 , 2001 ). These findings are consistent with those of others (reviewed by George 2003 ). Indeed, George ( 2003 ) suggested that steroids will only consistently enhance strength if three conditions are met: (1) steroids are given to individuals who have been training and who continue to train while taking steroids, (2) the experimental subjects have a high protein diet throughout the experiment, and (3) changes in performance are measured by the technique with which the individuals were training while taking steroids. That is, one may, or may not, find a change in bench-press performance if individuals trained with leg presses, and not bench presses, while taking steroids. We note that the confounding effect of training is a rather intuitive finding, but it does point out potential problems in studies of non-human animals, specifically laboratory studies, which we address below.

Given the effects of steroids on physiology and performance of human muscle, what can integrative biologists take away from these findings? We suggest that they can provide some valuable insights into the mechanisms of how hormones might regulate whole-animal performance traits in nonhuman animals. The most obvious lesson is that manipulating the circulating levels of testosterone, or its derivatives, increases overall strength, which has apparent benefits for performance in bursts, such as sprint speed. In contrast, there is little evidence from studies on humans for a positive effect on capacity for endurance, which is counter-intuitive, given the known effect of testosterone on hemoglobin concentrations and hematocrit. However, these same studies of humans also raise a host of issues that merit special consideration by researchers interested in hormonal effects on nonhuman animals, including effect of training, timing of administration, and dosage administered. We also argue that more information is needed on the long-term effects of hormonal manipulation on performance and fitness. Although recent studies suggest that increasing testosterone levels can enhance certain types of performance, we are not advocating or justifying the use of steroids by humans. There are numerous side effects of prolonged steroid use in humans, including cardiovascular problems, impaired reproductive function, altered behavior, increased risk of certain tumors and cancers, and decreased immune function, among others (reviewed by Pärssinen and Seppälä 2002 ; George 2003 ). These “side-effects” are in accordance with studies of nonhuman animals where higher testosterone levels are associated with such detrimental effects as increased loads of parasites, reduced immunocompetence, decreased body condition, reduced growth, and increased use of energy, ultimately resulting in reduced survival (Marler and Moore 1988 ; Folstad and Karter 1992 ; Salvador et al. 1996 ; Wikelski et al. 1999 , 2004 ; Moore et al. 2000 ; Peters 2000 ; Klukowski and Nelson 2001 ; Wingfield et al. 2001 ; Hau et al. 2004 ). Indeed, it is the presence of these very “side-effects” that has driven a great deal of research on behavioral and life-history tradeoffs mediated by testosterone (Ketterson and Nolan 1999 ; Ketterson et al. 2001 ). Higher levels of testosterone may enhance performance and increase success at some tasks, but its widespread “pleiotropic” effects on other aspects of the phenotype may result in a net detriment to fitness (Raouf et al. 1997 ; Reed et al. 2006 ; Ketterson et al. 2009).

We encourage researchers to complete more detailed studies of the interactions among hormones, morphology, and performance, especially across different types of performance traits (dynamic versus regulatory, see Husak et al. 2009a ). Comparative data on whether the same, or different, hormones affect the same performance traits in different taxa (e.g., burst speed in fish, sprint speed in lizards) would be useful for understanding how different species have evolved unique, or conserved, endocrine control of morphology and function. A comparative approach is important, as other studies have shown different effects of testosterone on performance in different taxa (e.g., an increase in endurance for rats and lizards, but none for humans), and more research is needed to determine whether such differences are valid or purely methodological. Even though testosterone is confined to vertebrates, it is possible that studies with invertebrates may reveal similar effects on performance via different hormones, e.g., recent work showing a seemingly similar role of juvenile hormone for invertebrates as testosterone has for vertebrates (Contreras-Garduno et al. 2009 ; see also Zera 2006 ; Zera et al. 2007 ; Lorenz and Gäde 2009).

Correlative studies relating endogenous circulating hormone levels to natural variation in performance traits can provide valuable insight into potential mechanistic regulators of performance, but manipulations allow a more detailed examination of cause-and-effect relationships. Whether performance can be manipulated by reduction (castration) or supplementation (implants) of testosterone in nonhuman animals will depend on the type of performance and how it is affected by circulating levels of the androgen. Many dynamic performance traits, especially maximal performance, may show different responses to exogenous hormone in the laboratory versus field, compared to coloration or “behavioral” traits. For example, supplementation with testosterone may rapidly increase display behavior or aggression in the laboratory (Lovern et al. 2001 ; Hews and Quinn 2003 ) compared to control animals, or corticosterone supplementation may decrease sexually selected color patterns (reviewed by Husak and Moore 2008 ). These examples are in contrast to supplementing testosterone in the laboratory and testing for an effect on performance. Aggression and coloration will not likely require training of the target trait to reveal an observed effect, whereas some performance traits may require training. Furthermore, regulatory performance traits (e.g., regulation of ions in seawater), on the other hand, may respond more directly to hormonal manipulation (see McCormick 2009), and will likely not require any training, but more empirical data are necessary to make generalizations.

It is also important to more closely inspect those traits that show no significant effect of testosterone on dynamic performance after manipulation in the laboratory. Such a “noneffect” may be due to numerous possibilities, the most obvious of which is that testosterone simply has no effect on a particular type of performance. However, a second possibility is that muscles involved in performance were not adequately trained during administration of supplemental testosterone, or there was no control of exercise during the period of testosterone administration. As an hypothetical example, one might not expect to see a large increase in the maximal flight speed of birds that were never allowed to fly following administration of exogenous testosterone. Indeed, Gallotia galloti lizards given exogenous testosterone were compared to lizards given sham implants and there was no difference in maximal bite force at the end of the experiment (K. Huyghe, J.F. Husak, R. Van Damme, M. Molina-Borja, A. Herrel, in review), despite increases in mass of the jaw muscles in testosterone-supplemented males. One possible explanation for this result is that these lizards did not “train” their jaw muscles enough while in captivity to increase muscle mass sufficiently to result in a measurable enhancement of performance. It is also possible that receptor density is very low or becomes low in trained muscles. Nevertheless, while training in animals seems straightforward in principle, in practice it is far trickier, and there also appear to be striking differences among species in the effects of training. Whereas some studies of mammals have successfully increased performance through training in a laboratory (Brooks and Fahey 1984 ; Astrand and Rodahl 1986 ), similar studies with lizards have found no effect (Gleeson 1979 ; Garland et al. 1987 ). In addition, while training might be successful with animals acclimated to a laboratory setting, inducement of stress, with a concomitant effect on corticosterone (Moore and Jessop 2003 ), and potentially circulating testosterone levels, is a significant confounding factor. Another complementary option is to use field studies, where experimental groups are released into the wild to “train” themselves while accomplishing their day-to-day tasks and performing naturally. Of course, this approach also cannot take into account variation in “training” within experimental groups, as individuals will likely use their performance traits in different ways when left to their own devices. Consequently, this approach could result in unpredictable results in how hormones impact performance, unless one accepts the unlikely assumption that all experimental animals are performing in the same ways. Further, a field approach also does not take into account other “pleiotropic” effects of increased (or decreased) testosterone on the phenotype (e.g., increased activity or conspicuousness to predators), which can eliminate potential benefits to fitness from enhanced performance due to testosterone supplementation.

Studies seeking to manipulate performance with testosterone supplementation should also consider the timing of experiments. For example, testosterone should ideally be increased or decreased during times when the hypothalamic–pituitary–gonad (HPG) axis is responsive and receptors are expressed in the appropriate target tissues. Seasonal sensitivity of the male HPG axis is well documented (Fusani et al. 2000 ; Jawor et al. 2006 ; Ball and Ketterson 2008 ), and such effects should be considered. For example, male green anoles ( Anolis carolinensis ) given exogenous testosterone after the end of the breeding season in a laboratory setting did not increase head size or bite-force performance (J. Henningsen, J. Husak, D. Irschick, and I. Moore, unpublished data), presumably because some or all of the relevant target tissues were no longer sensitive to androgens. On the other hand, male brown anoles ( Anolis sagrei ) did show enhanced maximal bite force when testosterone was supplemented at the beginning of the breeding season when the target tissues are presumably sensitive to androgens (Cox et al., in press). Timing of experimentation is thus critical for designing studies examining hormonal effects, and the interaction between timing and training should also be considered, as training effects may be relevant for some seasonal periods, but not for others.

A related issue concerns how much hormone to administer to experimental subjects. Studies of human steroid use typically involve supraphysiological doses of testosterone, as this is the typical regimen for steroid-abusing athletes (George 2003 ; Hartgens and Kuipers 2004 ). Indeed, many studies of steroid use by humans have been criticized for having experimental groups using physiological doses of testosterone. However, such criticism of seemingly unrealistic dosages highlights the differing goals of studies on human and non-human animals. Whereas studies of humans are focused on the role of supraphysiological doses on performance, those of nonhuman animals are more broadly interested in whether circulating testosterone affects performance within more natural bounds of variation (reviewed by Fusani et al. 2005 ; Fusani 2008 ). Supraphysiological doses can result in unexpected, or even counterintuitive, effects because endocrine systems tend to be homeostatic and compensatory after disruption via up- or down-regulation of various components within the system (Brown and Follett 1977 ).

There are few data on how testosterone affects dynamic performance during different stages of development, either in humans or in non-human animals. Practically all studies examining the effects of exogenous testosterone on humans have been on adults (reviewed by Hartgens and Kuipers 2004 ), but an increasing area of concern is steroid use by teenagers (Johnston et al. 2005 ). Because they are still developing physically, steroids may have dramatically different effects on dynamic performance in developing juveniles versus older adults. For example, steroid use is known to cause closure of growth plates of long bones (George 2003 ), potentially preventing growth to full height. Any manipulative hormone study examining effects on dynamic performance should also take baseline circulating levels into account, as there may be striking differences among age groups. For example, among sexually mature male green anole lizards in a well-studied New Orleans, Louisiana (USA) population, smaller “lightweight” males have lower circulating testosterone levels (Husak et al. 2007 , 2009b ), relatively smaller heads, and lower bite forces than do larger “heavyweight” males (see Lailvaux et al., 2004; Vanhooydonck et al., 2005a), with the difference apparently due to age (Irschick and Lailvaux 2006). Smaller males with low testosterone levels seem unable to produce higher levels (Husak et al. 2009b ), suggesting that testosterone levels are likely suppressed until a critical body size when the individuals become competitive with larger males. At this body size, elevated testosterone levels may accelerate growth of the head and increase bite force, although more data are needed to test this hypothesis. This ontogenetic increase in testosterone levels suggests that exogenous administration will have quite different effects on different age groups. For example, many hormones exert threshold effects (reviewed in Hews and Moore 1997 ) in which increased amounts above a threshold level produce little noticeable effect, suggesting that exogenous administration may accomplish little for larger lizards already with high testosterone levels, but may have substantial effects on smaller lizards with low testosterone levels.

In this context, long-term studies in animal species that focus on younger individuals (see Cox and John-Alder 2005 and references therein) might be useful for understanding the potential costs and benefits of hormones in improving or decreasing dynamic performance. Scientists are well-aware of some of the short-term activational effects of testosterone in humans and nonhuman animals, but while some long-term effects of supraphysiological doses on human health are recognized (see Hartgens and Kuipers 2004 ), we know far less about long-term effects of elevated (but not supraphysiological) testosterone levels on longevity and lifetime reproductive success of nonhuman animals. Ethical considerations may preclude long-term hormone implantation in humans and nonhuman animals, but correlating natural variation in testosterone levels both with performance traits and with other demographic features, such as longevity and lifetime reproductive success, would be useful for understanding chronic effects. Elegant studies with the dark-eyed junco ( Junco hyemalis ) (Ketterson et al. 2001 ; Reed et al. 2006 ) show complex trade-offs between different components of reproductive success (e.g., investment in extra-pair fertilizations versus parental care) as a result of testosterone supplementation; other similar trade-offs might be occurring over longer time spans in other animal species.

Despite popular interest in steroids and their effects on human athletic performance, we still lack a broad understanding of the effects of testosterone on performance in different animal species.

Our review of the literature on human steroids highlights several issues that could prove useful for integrative biologists interested in determining links among hormones, morphology, performance, and fitness in nonhuman animal species. First, studies of steroid use by humans reveal many caveats related to experimental design and interpretation that should be considered by those studying nonhuman animals (e.g., training, diet, dosage effects). Second, because of conflicting results of testosterone on different performance traits (e.g., burst performance versus endurance), more data are needed for such biomechanically opposing performance traits; testosterone may enhance multiple kinds of performance in some species, and only one kind in another. Third, while testosterone may have some general effects on dynamic performance in vertebrates, are there other hormones (e.g., juvenile hormone) that play a similar role in invertebrates? Finally, human steroid abusers often use various systems of “stacking”, where multiple drugs are taken in a specific order (George 2003 ), and such regimens are believed, by those who use them, to markedly increase dynamic performance. However, few studies have specifically examined how these regimes affect performance, or how the different regimes may be more, or less, effective in enhancing performance, either in humans or in non-human animal species. Furthermore, such practices are not restricted to multiple androgens, but may also include other hormones, such as growth hormone and insulin-like growth factor-I, which may, when taken exogenously, also enhance athletic performance and other aspects of the phenotype (Gibney et al. 2007 ). In this manner, the interactive effects of different hormone regimens for increasing animal performance are highly understudied. In conclusion, we have advocated an integrative approach for studying the evolution of morphology, function, and endocrine systems, and increased collaboration between researchers interested in human and in other animal systems may prove fruitful for both groups.

Financial support was provided by the National Science Foundation (IOS 0421917 to DJI and IOS 0852821 to I. T. Moore, JFH and DJI).

We are thankful to the symposium participants for fruitful discussions about hormones and performance. We thank the Society for Integrative and Comparative Biology, especially the Divisions of Animal Behavior, Comparative Endocrinology, and Vertebrate Morphology, for providing logistical and financial support.

Google Scholar

Google Preview

Author notes

Email alerts, citing articles via.

• Recommend to your Library

Affiliations

• Online ISSN 1557-7023
• Print ISSN 1540-7063
• Copyright © 2024 The Society for Integrative and Comparative Biology
• About Oxford Academic
• Publish journals with us
• University press partners
• What we publish
• New features  
• Open access
• Institutional account management
• Rights and permissions
• Get help with access
• Accessibility
• Advertising
• Media enquiries
• Oxford University Press
• Oxford Languages
• University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

• Copyright © 2024 Oxford University Press
• Cookie settings
• Cookie policy
• Privacy policy
• Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

• - Google Chrome

Intended for healthcare professionals

• Access provided by Google Indexer
• My email alerts
• BMA member login
• Username * Password * Forgot your log in details? Need to activate BMA Member Log In Log in via OpenAthens Log in via your institution

Search form

• Advanced search
• Search responses
• Search blogs
• Short term use of oral...

Short term use of oral corticosteroids and related harms among adults in the United States: population based cohort study

• Related content
• Peer review
• Akbar K Waljee , assistant professor 1 2 3 4 ,
• Mary A M Rogers , research associate professor 2 4 5 ,
• Paul Lin , statistican 2 ,
• Amit G Singal , associate professor 6 ,
• Joshua D Stein , associate professor 2 7 8 ,
• Rory M Marks , associate professor 9 ,
• John Z Ayanian , professor 2 5 8 ,
• Brahmajee K Nallamothu , professor 1 2 4 10
• 1 VA Center for Clinical Management Research, Ann Arbor, MI, USA
• 2 University of Michigan Medical School, Institute for Healthcare Policy and Innovation, Ann Arbor, MI, USA
• 3 University of Michigan Medical School, Department of Internal Medicine, Division of Gastroenterology and Hepatology, Ann Arbor, MI, USA
• 4 Michigan Integrated Center for Health Analytics and Medical Prediction (MiCHAMP), Ann Arbor, MI, USA
• 5 University of Michigan Medical School, Department of Internal Medicine, Division of General Medicine, Ann Arbor, MI, USA
• 6 Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
• 7 University of Michigan Medical School, Department of Ophthalmology and Visual Science, Ann Arbor, MI, USA
• 8 University of Michigan School of Public Health, Department of Health Management and Policy, University of Michigan, Ann Arbor, MI, USA
• 9 University of Michigan Medical School, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI, USA
• 10 University of Michigan Medical School, Department of Internal Medicine, Division of Cardiovascular Medicine, Ann Arbor, MI, USA
• Correspondence to: A K Waljee awaljee{at}med.umich.edu
• Accepted 14 March 2017

Objective  To determine the frequency of prescriptions for short term use of oral corticosteroids, and adverse events (sepsis, venous thromboembolism, fractures) associated with their use.

Design  Retrospective cohort study and self controlled case series.

Setting  Nationwide dataset of private insurance claims.

Participants  Adults aged 18 to 64 years who were continuously enrolled from 2012 to 2014.

Main outcome measures  Rates of short term use of oral corticosteroids defined as less than 30 days duration. Incidence rates of adverse events in corticosteroid users and non-users. Incidence rate ratios for adverse events within 30 day and 31-90 day risk periods after drug initiation.

Results  Of 1 548 945 adults, 327 452 (21.1%) received at least one outpatient prescription for short term use of oral corticosteroids over the three year period. Use was more frequent among older patients, women, and white adults, with significant regional variation (all P<0.001). The most common indications for use were upper respiratory tract infections, spinal conditions, and allergies. Prescriptions were provided by a diverse range of specialties. Within 30 days of drug initiation, there was an increase in rates of sepsis (incidence rate ratio 5.30, 95% confidence interval 3.80 to 7.41), venous thromboembolism (3.33, 2.78 to 3.99), and fracture (1.87, 1.69 to 2.07), which diminished over the subsequent 31-90 days. The increased risk persisted at prednisone equivalent doses of less than 20 mg/day (incidence rate ratio 4.02 for sepsis, 3.61 for venous thromboembolism, and 1.83 for fracture; all P<0.001).

Conclusion  One in five American adults in a commercially insured plan were given prescriptions for short term use of oral corticosteroids during a three year period, with an associated increased risk of adverse events.

Introduction

Corticosteroids are powerful anti-inflammatory drugs that have been used to treat a variety of diseases for over seven decades, dating back to their introduction for rheumatoid arthritis in 1949. 1 2 3 4 5 A strong driver of corticosteroid use is the potent symptomatic relief they give many patients. Yet long term use of corticosteroids is generally avoided, given the risks of serious acute complications such as infection, venous thromboembolism, avascular necrosis, and fracture, as well as chronic diseases such as diabetes mellitus, hypertension, osteoporosis, and other features of iatrogenic Cushing’s syndrome. 6 7 8 9 10 11 12 13 14 15 16 17 18 Indeed, corticosteroids are one of the most common reasons for admission to hospital for drug related adverse events, 19 and optimizing their long term use has been a major focus for clinical guidelines across diverse specialties for many years. 20 21 22 23 24 25 26

In contrast with long term use, however, the risk of complications from short term use is much less understood, and evidence is generally insufficient to guide clinicians. In the outpatient setting, brief courses of oral corticosteroids are often used to treat conditions with clearly defined inflammatory pathophysiology for which there is clinical consensus for efficacy, such as asthma, chronic obstructive lung disease, rheumatoid arthritis, and inflammatory bowel disease. 27 28 29 30 31 Yet anecdotally corticosteroids are also used often in the short term to treat many other prevalent conditions where evidence is lacking, such as non-specific musculoskeletal pain and rashes. Despite such pervasive indications for use of oral corticosteroids, little is known about the prescribing patterns of short term use of these drugs in the general adult population, or their potential harm.

In this study we characterized short term use of oral corticosteroids in a contemporary outpatient population, and the risk of acute adverse events. We describe those who use oral corticosteroids in the short term in an outpatient setting and then report (absolute) incidence rates of adverse events in users and non-users. We chose three acute events listed as adverse events on the Food and Drug Administration mandated drug label for oral corticosteroids (sepsis, venous thromboembolism, fracture). Given the inherent challenges related to confounding, we employed a self controlled case series (SCCS) design. This design has been used to examine drug and vaccine safety. 32 33 Using this method, each individual serves as his or her own control allowing for comparisons of adverse event rates during periods after exposure to corticosteroids versus rates during periods when not exposed.

Study design and population

The Clinformatics DataMart database (OptumInsight, Eden Prairie, MN) contains comprehensive, deidentified records of enrollees covered through a large nationwide healthcare insurer and its pharmacy services for outpatient drugs. All enrollees are included in a denominator file, regardless of whether they received services (eg, clinic visits, drug prescriptions, hospital admissions).

We identified all adults aged 18 to 64 years who were continuously enrolled between 1 January 2012 and 31 December 2014 (n=2 234 931). Those who were 65 years or older at any point during the study were excluded, owing to their eligibility for the federal Medicare program.

Patients were also required to have at least one year of continuous enrollment before the study period (1 January 2011 to 31 December 2011) to capture past use of corticosteroids and baseline comorbid conditions. To focus on new users, we excluded those who received any oral corticosteroids during 2011 (n=293 456). In addition, we excluded from the study cohort enrollees exclusively receiving non-oral forms of corticosteroids (eg, inhaler, intravenous route, or intra-articular injections only) or prescriptions for oral budesonide (n=102 243), and those with solid organ or bone marrow transplants, or malignancy (n=224 658) (see web appendix table 1). We also excluded patients who were prescribed oral corticosteroids for 30 days or more cumulatively over the study period (n=28 540). Finally, we excluded those with a history of adverse events in 2011 (n=37 089) (fig 1 ⇓ ). Non-users in the study cohort were defined as those without any corticosteroid prescriptions who remained in the cohort after the exclusions. No additional patients were excluded from the study.

Fig 1  Flow diagram of study inclusion and exclusion criteria

• Download figure
• Open in new tab
• Download powerpoint

For each enrollee, we obtained demographic information on age, sex, race or ethnicity, highest level of education, and region of the country based on a residential zip code. Race and ethnicity were identified using information obtained by OptumInsight from public records (eg, driver’s license data), the surname and first names of the beneficiary, and the census block of residence (E-Tech, Ethnic Technologies, South Hackensack, NJ). Studies comparing a similar approach with information collected from self report showed a positive predictive value of 71%. 34 Missing demographic variables were uncommon (<1%) and are listed as “unknown” for the descriptive analyses only. Comorbid conditions were ascertained from outpatient and inpatient claims available for each enrollee during the study period using ICD-9-CM (international classification of diseases, ninth revision) diagnosis codes that were subsequently grouped into Elixhauser categories. 35

Our primary exposure of interest was an outpatient prescription for an oral formulation of corticosteroids for less than 30 days, as obtained from detailed information in each pharmacy claim. Oral corticosteroid was defined by the dosage form, as categorized by the National Drug Data File from First Data Bank. The duration of corticosteroid use was based on the “days supply” variable provided within the pharmacy claim, which was defined as the “estimated day count the medication supply should last.” Importantly, this information captures actual prescriptions filled (not just prescriptions written). To calculate standardized doses for each patient, all corticosteroid formulations were converted into a daily dose based on prednisone equivalent doses (see web appendix table 2). 36 37 38 We also identified multiple outpatient prescriptions for patients and tabulated the number of repeated doses.

Among all patients in the study cohort, we identified the specialty type of the prescribing physician and clinical conditions for which corticosteroids were administered by linking a patient’s first prescription with the principal ICD-9-CM diagnosis code in the outpatient claim closest to the date of the prescription. If the closest claim was beyond three days from the prescription, we labeled this information for that patient as unknown. Overall, we were able to link 215 639 of 327 452 (65.9%) prescribing physicians and 278 425 of 327 452 (85.0%) patients who received a prescription to an ICD-9-CM diagnosis code. Diagnosis codes were grouped using clinical classification software obtained from the Agency for Healthcare Research and Quality. 35 39

We assessed three acute adverse events associated with short term corticosteroid use: sepsis, venous thromboembolism, and fractures. These events were identified using ICD-9-CM diagnosis codes that reflected acute presentations, with chronic or personal history codes not included (see web appendix table 3). We specifically selected these events as they represent a broad range of corticosteroid related acute complications. Each also has been listed on the FDA mandated drug label as possible adverse reactions, can be reliably identified in claims data, and has supporting evidence of pathogenesis early after drug initiation was available. 17 40 41 42 43 44 45 46 For sepsis, the outcome was admission to hospital for reason of sepsis (inpatient claims with a primary diagnosis of sepsis). For venous thromboembolism and fractures, we used both outpatient and inpatient claims to identify events.

Statistical analyses

Description of corticosteroid users.

We tabulated short term use of oral corticosteroids by age group (in 2014), sex, race, education, region, and number of Elixhauser comorbidities (grouped as 0, 1 to 2, and ≥3). Student t tests and χ 2 tests were used to assess differences by group. Regional variation in corticosteroid use was graphed by census division. We ranked the most common reasons for visits associated with the prescription, as well as specialty types of the prescribing providers.

Incidence rates of adverse events

For the entire cohort we calculated incidence rates of adverse events per 1000 person years at risk for corticosteroid users and non-users. Rates were also stratified by age, sex, and race. In addition, we calculated the cumulative risk of adverse events during the five to 90 day period after a clinic visit for corticosteroid users and non-users.

Self controlled case series

To control for patient specific characteristics while investigating the risk of adverse events, we used a self controlled case series (SCCS) design. 32 33 47 This method uses a within person approach to compare the rates of events after corticosteroid use (5-30 days and 31-90 days after the prescription was filled) with the rates before use (see web appendix figure 1). To be conservative, we modified the SCCS design so that adverse events within a four day window of when the prescription was filled were excluded to remove those who might have potentially received the oral corticosteroid concomitantly with the adverse event.

To preclude capturing multiple follow-up visits after the initial diagnosis of an adverse event, we only recorded the first event. Those who experienced an adverse event in the prestudy period of 2011 were excluded to avoid detecting legacy effects from past episodes. Patients were excluded if they were admitted to hospital within a 14 day period before the corticosteroid prescription date so that potential effects related to a recent hospital admission would be removed. Adjustment was made for time varying covariates related to concomitant drug use. In these analyses, the most commonly used classes of drugs (42 classes) were coded for each period and included in the full model; only those drug classes associated with each outcome (sepsis, venous theomboembolism, fracture) were retained in the final models.

Fixed (conditional) Poisson regression was used to calculate incidence rate ratios, offset by the natural logarithm of the days at risk to correct for differences in the lengths of observation. Effect modification by demographic factors (age, sex, race) were assessed by an interaction term.

Sensitivity analyses

We performed an analysis to deal with concerns that we were simply detecting more adverse events as a result of exposure to medical care rather than exposure to corticosteroids. For this analysis, we compared 30 day rates of hospital admissions for sepsis, venous thromboembolism, and fractures after a clinic visit in patients with matched diagnoses who did not receive corticosteroids and those who did receive corticosteroids after adjusting for age, sex, and race. Secondly, we used the cohort from the SCCS design and recalculated the incidence rate ratios after stratification by respiratory conditions or musculoskeletal conditions. These analyses assessed whether adverse events were being driven potentially by misdiagnosis (eg, sepsis may be more common because pneumonia is misdiagnosed as asthma, or fracture may be more common because vertebral fracture is misdiagnosed as back strain). Thirdly, in another sensitivity analysis we excluded patients who were using concomitant non-oral forms of corticosteroids. Lastly, we extended the four day period around the date of the prescription being filled to a seven day period.

Analyses were conducted with SAS software, v9.4 (SAS Institute), and Stata/MP14.1 (StataCorp, College Station, TX). Two tailed P values are reported for all analyses, with α=0.05. The institutional review board of the University of Michigan determined the study to be exempt from further review and waived the requirement for informed consent.

Patient involvement

No patients were involved in setting the research question or the outcome measures, nor were they involved in developing plans for recruitment, design, or implementation of the study. No patients were asked to advise on interpretation or writing up of results. There are no plans to disseminate the results of the research to study participants or the relevant patient community.

Among 1 548 945 adults in the study cohort, 327 452 (21.1%) received at least one outpatient prescription for short term oral corticosteroids during the three year study period. The mean age for users was 45.5 (SD 11.6) years compared with 44.1 (SD 12.2) years for non-users (P<0.001). Among the 327 452 corticosteroid users, the median number of days of use was 6 (interquartile range 6-12 days) with 47.4% (n=155 171 of 327 452) receiving treatment for seven or more days. Overall, the median prednisone equivalent daily dose was 20 mg/day (interquartile range 17.5-36.8 mg/day) with 23.4% (n=76 701 of 327 452) receiving ≥40 mg/day. The most common prescription written for oral corticosteroids was a six day methylprednisolone “dosepak,” which accounted for 46.9% (n=216 437 of 461 208) of prescriptions during the study period. Among corticosteroid users, 70.5% (n=230 980 of 327 452) received one course of treatment, 20.7% (n=67 732 of 327 452) received two courses, and 8.8% (n=28 740 of 327 452) received three or more courses. For those patients with two or more prescriptions, the average prescription count was 2.4 (SD 0.7).

Compared with non-users, short term oral corticosteroid users were more often older, women, white, and had a greater number of comorbid conditions (table 1 ⇓ , all P<0.001). People residing in the Pacific region had the lowest use of short term oral corticosteroids (12.4%, n=15 762 of 127 112), whereas people in the east south central region (29.4%, n=14 892 of 50 669) and west south central region (27.6%, n=66 353 of 240 678) had the highest usage (see web appendix figure 2).

Demographic characteristics of participants according to short term use or non-use of oral corticosteroids

• View inline

The most common indications for short term oral corticosteroid use were upper respiratory tract infections, spinal conditions, and intervertebral disc disorders, allergies, bronchitis, and (non-bronchitic) lower respiratory tract disorders (see web appendix table 4). These five conditions were associated with about half of all prescriptions. The two most common specialty types of physicians prescribing short term oral corticosteroids were family medicine and general internal medicine, accounting for most prescriptions (see web appendix table 4). These drugs were also frequently prescribed by specialists in emergency medicine, otolaryngology, and orthopedics.

Incidence rates of sepsis, venous thromboembolism, and fracture were statistically significantly higher in short term users of oral corticosteroid than in non-users (table 2 ⇓ ). The differences were evident across age, sex, and race stratums. Fractures were the most common complication in users (21 events for every 1000 users annually), followed by venous thromboembolism (5 events for every 1000 users annually) and hospital admissions for sepsis (2 events for every 1000 users annually).

Incidence rates of adverse events by short term use of oral corticosteroids

The absolute risk of an adverse event during the five to 90 day period after a clinic visit was calculated. For those patients with a visit, the risk of hospital admission for sepsis was 0.05% (n=170 of 327 452) in steroid users compared with 0.02% (n=293 of 1 221 493) in non-users during this period. The risk of venous thromboembolism was 0.14% (n=472 of 327 452) in users compared with 0.09% (n=1054 of 1 221 493) in non-users, and the risk of fracture was 0.51% (n=1657 of 327 452) in users compared with 0.39% (n=4735 of 1 221 493) in non-users in the 90 days after a clinic visit.

Table 3 ⇓ displays the results of the SCCS. Overall, risks for sepsis, venous thromboembolism, and fracture increased within the first 30 days after initiation of corticosteroids. For example, the risk of hospital admission for sepsis increased fivefold (above baseline risk) after oral corticosteroids were used. This relation was consistent across doses. The long term risk for adverse events (31-90 days) diminished as the time from initial exposure increased.

Incidence rate ratios for adverse events associated with short term use of oral corticosteroids

To examine risks for particular types of patients, we explored effect modification by age, sex, and race. No significant effect modification was found after adjustment for time varying covariates, except for race; white patients had a higher short term risk of fractures than non-white patients (incidence rate ratio 2.02, 95% confidence interval 1.81 to 2.26 for white patients; 1.42, 1.14 to 1.77 for non-white patients; P=0.006 interaction term).

Web appendix table 5 displays the results of our analysis of 30 day rates of hospital admission for sepsis, venous thromboembolism, and fractures after a clinic visit in patients with matched diagnoses who did not receive corticosteroids and those who did receive corticosteroids after adjusting for age, sex, and race. It shows consistently higher incidence rates of adverse events in the patients who received corticosteroids. In the SCCS stratified by respiratory conditions or musculoskeletal conditions, the incidence rate ratios were recalculated (table 4 ⇓ ). The 30 day risk of venous thromboembolism, fracture, and hospital admission for sepsis was statistically significantly increased for patients presenting with both respiratory conditions and musculoskeletal conditions. When we excluded patients using concomitant non-oral forms of corticosteroids from the analyses, the results were similar (see web appendix table 6). In the 5-30 day window the incidence rate ratio for sepsis was 4.84, for venous thromboembolism was 3.29, and for fracture was 1.92 (all P<0.001). Extending the four day period around the date of prescription to a seven day period also did not appreciably change the results (see web appendix table 7). The incidence rate ratio for sepsis was 4.33 (95% confidence interval 3.04 to 6.17), for venous thromboembolism was 2.94 (2.42 to 3.56), and for fracture was 1.65 (1.49 to 1.84).

Incidence rate ratios for adverse events associated with short term use of oral corticosteroids, by reason for medical visit

In this large, population based study of privately insured non-elderly (<64 years) adults in the US, one in five received a new outpatient prescription for short term use of oral corticosteroids over a three year period. These drugs were used for a wide range of conditions, such as upper respiratory tract infections, spinal conditions, and allergies and were commonly prescribed by both generalist and specialist physicians. Importantly, these prescriptions were associated with statistically significantly higher rates of sepsis, venous thromboembolism, and fracture despite being used for a relatively brief duration.

Comparison with other studies

Estimates of corticosteroid use from cross sectional studies range from 0.5% to 1.2% over various study periods. 7 9 10 An analysis of the National Health and Nutrition Examination Survey described self reported use of drugs taken within the previous 30 days. 7 Its findings indicated a mean duration of corticosteroid use exceeding four years among users—thus capturing a larger proportion of chronic treatment but potentially underreporting short term use. Furthermore, although the analyses were weighted, the actual sample of corticosteroid users included only 356 people. In our longitudinal analysis of 1.5 million insured Americans, the incidence was approximately 7% for short term oral corticosteroid use on a yearly basis.

Though the long term complications of chronic corticosteroid use are well known, there is a paucity of clinical data on the potential short term adverse effects of corticosteroid use, despite the existence of pathophysiological evidence suggesting possible early changes after drug initiation. For example, the impact of corticosteroids on the immune system has been widely studied, and in randomized controlled trials of prednisone (versus placebo) in healthy adults there were effects on peripheral cell lines (eg, peripheral white blood cells) within the first day after drug ingestion that were noticeable with 10 mg, 25 mg, and 60 mg doses. 48 49 Rapid alteration in markers of bone metabolism has also been documented with the initiation of corticosteroid use; mean serum concentrations of osteocalcin and both serum propeptide of type I N-terminal and C-terminal procollagen were statistically significantly decreased in the early weeks after starting prednisone. 43 The mechanisms underlying the increase in venous thromboembolism are not fully known. However, infection is a common trigger of thrombosis, 50 suggesting that both venous thromboembolism and sepsis may be potentially mediated through changes in the immune system. Further work is needed to clarify whether and how our observations in this large population may be linked to potential causal pathways.

Strengths and limitations of this study

Our findings are particularly of concern given the large number of patients exposed to short term oral corticosteroids in the general adult population. Clinical guidelines typically recommend using the lowest dose of steroids for the shortest period to prevent adverse events. 24 25 However, we found that even short durations of use, regardless of dose, were associated with increased risks of adverse events and that few patients were using very low doses. Only 6.3% of the prescriptions were for a prednisone equivalent dose of less than 17.5 mg/day, and 1.0% of prescriptions were for less than 7.5 mg/day; therefore, we were unable to examine events in patients given very low doses for short periods. A major reason for the higher than expected doses was the widespread use of “fixed dose” methylprednisolone dosepaks that are tapered over a short period. These dosepaks offer ease of use but do not permit the individualization of drug dosing to minimize exposure.

A substantial challenge to improving use of oral corticosteroids will be the diverse set of conditions and types of providers who administer these drugs in brief courses. This raises the need for early general medical education of clinicians about the potential risks of oral corticosteroids and the evidence basis for their use, given that use may not be specific to a particular disease or specialty. Suprisingly, the most common prescribers were not subspecialists, such as rheumatologists, who are most experienced with treating inflammatory conditions and the long term use of these drugs. We also found that the most common indications for corticosteroid use included conditions such as upper respiratory tract infections, spinal conditions, and allergies, which often have marginal benefit and for which alternate treatments may be similarly effective and safer. For example, a multimodal pain treatment regimen can be used to treat spinal pain, and non-sedating antihistamines can be used for allergies. An examination of potential determinants of corticosteroid use will be needed to inform future intervention strategies. If corticosteroid use is driven by patient preferences, education on the potential harms should be expanded. If prescriptions are primarily driven by provider decisions, decision support tools to identify alternatives to corticosteroids (eg, non-steroidal anti-inflammatory drugs for acute gout 30 or tricyclic antidepressants for neuropathic pain 51 ) may be a more effective approach, but additional studies will be required to substantiate these possible alternatives as some of these drugs are available over the counter.

Our study has several limitations. Firstly, our cohort only includes commercially insured adults and excludes patients aged more than 64 years, which potentially limits the generalisability of our findings. We focused on younger adults as these individuals tend to have fewer comorbid conditions, and therefore our findings may be less likely to be biased by the high prevalence of age related comorbid conditions. Although our reference population is commercially insured adults, we have no reason to suspect this characteristic should bias a possible association between corticosteroid use and adverse events. Secondly, we determined the indication for corticosteroid use and the specific provider prescribing the drug by linking outpatient claims recorded most closely to the prescription date; thus we might have misclassified some treatment indications and specialties. Thirdly, we were unable to adequately assess the risks of adverse events at very low doses of corticosteroids, given the infrequency of use at these doses.

Fourthly, we did not evaluate all of the possible adverse events linked to oral corticosteroids but focused on three acute adverse reactions. This makes our findings even more striking as they are likely a conservative estimate of the associated risks of adverse events. For example, we only focused on hospital admissions for sepsis, ignoring less serious but likely important infections, and we did not assess some adverse events such as behavioral or psychiatric conditions. In addition, a dose- response trend was not seen and may reflect our selection criteria of using prescriptions of less than 30 days. Fifthly, although we used a within person approach to control for genetic predisposition, health related behaviors, and comorbid conditions and adjusted for time varying use of different drugs, other time varying factors could be differentially distributed between the risk and baseline periods. However, the incidence rate ratios were strong (many >3.0) so that any residual confounding would have to be appreciable to fully explain our findings. Assumptions of the SCCS design were mitigated by using only the first event for each of the three outcomes, and therefore independence of recurrent events and the potential influence of past events on subsequent drug use (if this occurred) yielded incidence rate ratios that might be somewhat conservative. Survival bias was not an issue since by design all patients were alive during the periods when the outcomes were measured (ie, the comparator period was before the first use of corticosteroids).

Oral corticosteroids are frequently prescribed for short term use in the US for a variety of common conditions and by numerous provider specialties. Over a three year period, approximately one in five American adults in a commercially insured plan used oral corticosteroids for less than 30 days. The short term use of these drugs was associated with increased rates of sepsis, venous thromboembolism, and fracture; even at relatively low doses. Additional studies are needed to identify optimal use of corticosteroids and to explore whether treatment alternatives may improve patient safety.

What is already known on this topic

Complications with chronic use of corticosteroids include a wide spectrum of effects on the cardiovascular, musculoskeletal, digestive, endocrine, ophthalmic, skin, and nervous systems

However, the potential risks associated with the use of short term oral corticosteroids and their overall use in a general population has not been fully characterized

What this study adds

This study of 1.5 million privately insured adults (18-64 years) in the US found that one in five patients in an outpatient setting used short term oral corticosteroid over a three year period (2012-14)

Within 30 days of corticosteroid initiation, the incidence of acute adverse events that result in major morbidity and mortality (sepsis, venous thromboembolism, fracture) increased by twofold, to fivefold above background rates

Greater attention to initiating prescriptions of these drugs and monitoring for adverse events may potentially improve patient safety

Contributors: AKW and BKN had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. They are the guarantors. AKW and MAMR conceived and designed the study. All authors acquired, analysed, and interpreted the data; critically revised the manuscript; and gave final approval of the manuscript. AKW and BKN drafted the manuscript. AKW, MAMR, and PL were responsible for the figures. The authors are solely responsible for the design, conduct, data analyses, and drafting and editing of the manuscript and its final content. The contents do not represent the views of the US Department of Veterans Affairs or the United States government.

Funding: AKW is supported by a career development grant award (CDA 11-217) from the United States Department of Veterans Affairs Health Services Research and Development Service. AKW and BKN are supported by funding from the Michigan Institute for Data Science (MIDAS). JDS is supported by grants from Research to Prevent Blindness and WK Kellogg Foundation. Data acquisition and statistical and administrative support was supported by the Institute for Healthcare Policy and Innovation at the University of Michigan. These funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

Ethical approval: This study was approved by the University of Michigan institutional research board.

Data sharing: No additional data are available.

Transparency: The lead author affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ .

• ↵ Spies TD, Stone RE, et al. Deoxycortone with ascorbic acid versus adrenocorticotropic hormone in rheumatoid arthritis. Lancet 1949 ; 357 : 1219 - 21 . doi:10.1016/S0140-6736(49)91919-4   pmid:15408152 . OpenUrl
• ↵ Bunim JJ, Pechet MM, Bollet AJ. Studies on metacortandralone and metacortandracin in rheumatoid arthritis; antirheumatic potency, metabolic effects, and hormonal properties. J Am Med Assoc 1955 ; 357 : 311 - 8 . doi:10.1001/jama.1955.02950210007003   pmid:13221414 . OpenUrl
• ↵ Carone FA, Liebow AA. Acute pancreatic lesions in patients treated with ACTH and adrenal corticoids. N Engl J Med 1957 ; 357 : 690 - 7 . doi:10.1056/NEJM195710102571502   pmid:13477372 . OpenUrl
• ↵ Rhen T, Cidlowski JA. Antiinflammatory action of glucocorticoids--new mechanisms for old drugs. N Engl J Med 2005 ; 357 : 1711 - 23 . doi:10.1056/NEJMra050541   pmid:16236742 . OpenUrl
• ↵ Herzog HL, Nobile A, Tolksdorf S, Charney W, Hershberg EB, Perlman PL. New antiarthritic steroids. Science 1955 ; 357 : 176 . doi:10.1126/science.121.3136.176   pmid:13225767 . OpenUrl
• ↵ Gudbjornsson B, Juliusson UI, Gudjonsson FV. Prevalence of long term steroid treatment and the frequency of decision making to prevent steroid induced osteoporosis in daily clinical practice. Ann Rheum Dis 2002 ; 357 : 32 - 6 . doi:10.1136/ard.61.1.32   pmid:11779755 . OpenUrl
• ↵ Overman RA, Yeh J-Y, Deal CL. Prevalence of oral glucocorticoid usage in the United States: a general population perspective. Arthritis Care Res (Hoboken) 2013 ; 357 : 294 - 8 . doi:10.1002/acr.21796   pmid:22807233 . OpenUrl
• ↵ Sarnes E, Crofford L, Watson M, Dennis G, Kan H, Bass D. Incidence and US costs of corticosteroid-associated adverse events: a systematic literature review. Clin Ther 2011 ; 357 : 1413 - 32 . doi:10.1016/j.clinthera.2011.09.009   pmid:21999885 . OpenUrl
• ↵ van Staa TP, Leufkens HG, Abenhaim L, Begaud B, Zhang B, Cooper C. Use of oral corticosteroids in the United Kingdom. QJM 2000 ; 357 : 105 - 11 . doi:10.1093/qjmed/93.2.105   pmid:10700481 . OpenUrl
• ↵ Walsh LJ, Wong CA, Pringle M, Tattersfield AE. Use of oral corticosteroids in the community and the prevention of secondary osteoporosis: a cross sectional study. BMJ 1996 ; 357 : 344 - 6 . doi:10.1136/bmj.313.7053.344   pmid:8760745 . OpenUrl
• ↵ Wei L, MacDonald TM, Walker BR. Taking glucocorticoids by prescription is associated with subsequent cardiovascular disease. Ann Intern Med 2004 ; 357 : 764 - 70 . doi:10.7326/0003-4819-141-10-200411160-00007   pmid:15545676 . OpenUrl
• ↵ Gurwitz JH, Bohn RL, Glynn RJ, Monane M, Mogun H, Avorn J. Glucocorticoids and the risk for initiation of hypoglycemic therapy. Arch Intern Med 1994 ; 357 : 97 - 101 . doi:10.1001/archinte.1994.00420010131015   pmid:8267494 . OpenUrl
• ↵ Stuijver DJF, Majoor CJ, van Zaane B, et al. Use of oral glucocorticoids and the risk of pulmonary embolism: a population-based case-control study. Chest 2013 ; 357 : 1337 - 42 . doi:10.1378/chest.12-1446   pmid:23258429 . OpenUrl
• ↵ Curtis JR, Westfall AO, Allison J, et al. Population-based assessment of adverse events associated with long-term glucocorticoid use. Arthritis Rheum 2006 ; 357 : 420 - 6 . doi:10.1002/art.21984   pmid:16739208 . OpenUrl
• ↵ del Rincón I, Battafarano DF, Restrepo JF, Erikson JM, Escalante A. Glucocorticoid dose thresholds associated with all-cause and cardiovascular mortality in rheumatoid arthritis. Arthritis Rheumatol 2014 ; 357 : 264 - 72 . doi:10.1002/art.38210   pmid:24504798 . OpenUrl
• ↵ Dessein PH, Joffe BI, Stanwix AE, Christian BF, Veller M. Glucocorticoids and insulin sensitivity in rheumatoid arthritis. J Rheumatol 2004 ; 357 : 867 - 74 . pmid:15124244 . OpenUrl
• ↵ Johannesdottir SA, Horváth-Puhó E, Dekkers OM, et al. Use of glucocorticoids and risk of venous thromboembolism: a nationwide population-based case-control study. JAMA Intern Med 2013 ; 357 : 743 - 52 . doi:10.1001/jamainternmed.2013.122   pmid:23546607 . OpenUrl
• ↵ Davis JM 3rd, , Maradit Kremers H, Crowson CS, et al. Glucocorticoids and cardiovascular events in rheumatoid arthritis: a population-based cohort study. Arthritis Rheum 2007 ; 357 : 820 - 30 . doi:10.1002/art.22418   pmid:17330254 . OpenUrl
• ↵ Weiss AJ, Elixhauser A, Bae J, Encinosa W. Origin of adverse drug events in US hospitals, 2011. 2013 . www.ncbi.nlm.nih.gov/books/NBK169247/
• ↵ Grossman JM, Gordon R, Ranganath VK, et al. American College of Rheumatology 2010 recommendations for the prevention and treatment of glucocorticoid-induced osteoporosis. Arthritis Care Res (Hoboken) 2010 ; 357 : 1515 - 26 . doi:10.1002/acr.20295   pmid:20662044 . OpenUrl
• ↵ Melmed GY, Siegel CA. Quality improvement in inflammatory bowel disease. Gastroenterol Hepatol (N Y) 2013 ; 357 : 286 - 92 . pmid:23943663 . OpenUrl
• ↵ Gerritsen AAM, de Krom MCTFM, Struijs MA, Scholten RJPM, de Vet HCW, Bouter LM. Conservative treatment options for carpal tunnel syndrome: a systematic review of randomised controlled trials. J Neurol 2002 ; 357 : 272 - 80 . doi:10.1007/s004150200004   pmid:11993525 . OpenUrl
• ↵ Goldberg H, Firtch W, Tyburski M, et al. Oral steroids for acute radiculopathy due to a herniated lumbar disk: a randomized clinical trial. JAMA 2015 ; 357 : 1915 - 23 . doi:10.1001/jama.2015.4468   pmid:25988461 . OpenUrl
• ↵ Vestbo J, Hurd SS, Agustí AG, et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med 2013 ; 357 : 347 - 65 . doi:10.1164/rccm.201204-0596PP   pmid:22878278 . OpenUrl
• ↵  National Asthma Education and Prevention Program. Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma-Summary Report 2007. J Allergy Clin Immunol 2007 ; 357 ( Suppl ): S94 - 138 . doi:10.1016/j.jaci.2007.09.029   pmid:17983880 . OpenUrl
• ↵ Singh JA, Saag KG, Bridges SL Jr, et al. 2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis. Arthritis Rheumatol 2016 ; 357 : 1 - 26 . doi:10.1002/art.39480   pmid:26545940 . OpenUrl
• ↵ Littenberg B, Gluck EH. A controlled trial of methylprednisolone in the emergency treatment of acute asthma. N Engl J Med 1986 ; 357 : 150 - 2 . doi:10.1056/NEJM198601163140304   pmid:3510384 . OpenUrl
• ↵ Niewoehner DE, Erbland ML, Deupree RH, et al. Department of Veterans Affairs Cooperative Study Group. Effect of systemic glucocorticoids on exacerbations of chronic obstructive pulmonary disease. N Engl J Med 1999 ; 357 : 1941 - 7 . doi:10.1056/NEJM199906243402502   pmid:10379017 . OpenUrl
• ↵ Akdis CA, Akdis M, Bieber T, et al. Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report. Blackwell Publishing, 2006 : 969 - 87 .
• ↵ Rainer TH, Cheng CH, Janssens HJEM, et al. Oral prednisolone in the treatment of acute gout: a pragmatic, multicenter, double-blind, randomized trial. Ann Intern Med 2016 ; 357 : 464 - 71 . doi:10.7326/M14-2070   pmid:26903390 . OpenUrl
• ↵ Margolin ML, Krumholz MP, Fochios SE, Korelitz BI. Clinical trials in ulcerative colitis: II. Historical review. Am J Gastroenterol 1988 ; 357 : 227 - 43 . pmid:2894170 . OpenUrl
• ↵ Schneeweiss S, Avorn J. A review of uses of health care utilization databases for epidemiologic research on therapeutics. J Clin Epidemiol 2005 ; 357 : 323 - 37 . doi:10.1016/j.jclinepi.2004.10.012   pmid:15862718 . OpenUrl
• ↵ Whitaker HJ, Farrington CP, Spiessens B, Musonda P. Tutorial in biostatistics: the self-controlled case series method. Stat Med 2006 ; 357 : 1768 - 97 . doi:10.1002/sim.2302   pmid:16220518 . OpenUrl
• ↵ DeFrank JT, Bowling JM, Rimer BK, Gierisch JM, Skinner CS. Triangulating differential nonresponse by race in a telephone survey. Prev Chronic Dis 2007 ; 357 : A60 . pmid:17572964 . OpenUrl
• ↵ Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for use with administrative data. Med Care 1998 ; 357 : 8 - 27 . doi:10.1097/00005650-199801000-00004   pmid:9431328 . OpenUrl
• ↵ Meikle AW, Tyler FH. Potency and duration of action of glucocorticoids. Effects of hydrocortisone, prednisone and dexamethasone on human pituitary-adrenal function. Am J Med 1977 ; 357 : 200 - 7 . doi:10.1016/0002-9343(77)90233-9   pmid:888843 . OpenUrl
• ↵ Dixon JS. Second-Line Agents in the Treatment of Arthritis. Informa Health Care, 1991 .
• ↵ Singer M, Webb A. Oxford Handbook of Critical Care. Oxford University Press, 2009 doi:10.1093/med/9780199235339.001.0001 .
• ↵ Elixhauser A, Steiner C, Palmer L. Clinical Classifications Software (CCS) , 2014 . U.S. Agency for Healthcare Research and Quality. www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp
• ↵ Migita K, Arai T, Ishizuka N, et al. Rates of serious intracellular infections in autoimmune disease patients receiving initial glucocorticoid therapy. PLoS One 2013 ; 357 : e78699 . OpenUrl
• ↵ Dovio A, Perazzolo L, Osella G, et al. Immediate fall of bone formation and transient increase of bone resorption in the course of high-dose, short-term glucocorticoid therapy in young patients with multiple sclerosis. J Clin Endocrinol Metab 2004 ; 357 : 4923 - 8 . doi:10.1210/jc.2004-0164   pmid:15472186 . OpenUrl
• ↵ Pearce G, Ryan PF, Delmas PD, Tabensky DA, Seeman E. The deleterious effects of low-dose corticosteroids on bone density in patients with polymyalgia rheumatica. Br J Rheumatol 1998 ; 357 : 292 - 9 . doi:10.1093/rheumatology/37.3.292   pmid:9566670 . OpenUrl
• ↵ Ton FN, Gunawardene SC, Lee H, Neer RM. Effects of low-dose prednisone on bone metabolism. J Bone Miner Res 2005 ; 357 : 464 - 70 . doi:10.1359/JBMR.041125   pmid:15746991 . OpenUrl
• ↵ Leong GM. Center, Jacqueline R., Henderson NK, Eisman JA. Chapter 44. Glucocorticoid-Induced Osteoporosis: Basic Pathological Mechanisms, Clinical Features, and Management in the New Millennium. In: Marcus R, Feldman D, Kelsey J, eds. Osteoporosis (2nd ed). San Diego: Academic Press; 2001:169-93.
• ↵ Pouw EM, Prummel MF, Oosting H, Roos CM, Endert E. Beclomethasone inhalation decreases serum osteocalcin concentrations. BMJ 1991 ; 357 : 627 - 8 . doi:10.1136/bmj.302.6777.627   pmid:2012877 . OpenUrl
• ↵ Nielsen HK, Thomsen K, Eriksen EF, Charles P, Storm T, Mosekilde L. The effects of high-dose glucocorticoid administration on serum bone gamma carboxyglutamic acid-containing protein, serum alkaline phosphatase and vitamin D metabolites in normal subjects. Bone Miner 1988 ; 357 : 105 - 13 . pmid:3263890 . OpenUrl
• ↵ Gagne JJ, Fireman B, Ryan PB, et al. Design considerations in an active medical product safety monitoring system. Pharmacoepidemiol Drug Saf 2012 ; 357 : 32 - 40 . OpenUrl
• ↵ Hahn BH, MacDermott RP, Jacobs SB, Pletscher LS, Beale MG. Immunosuppressive effects of low doses of glucocorticoids: effects on autologous and allogeneic mixed leukocyte reactions. J Immunol 1980 ; 357 : 2812 - 7 . pmid:6445384 . OpenUrl
• ↵ Kauh E, Mixson L, Malice M-P, et al. Prednisone affects inflammation, glucose tolerance, and bone turnover within hours of treatment in healthy individuals. Eur J Endocrinol 2012 ; 357 : 459 - 67 . doi:10.1530/EJE-11-0751   pmid:22180452 . OpenUrl
• ↵ Rogers MAM, Levine DA, Blumberg N, Flanders SA, Chopra V, Langa KM. Triggers of hospitalization for venous thromboembolism. Circulation 2012 ; 357 : 2092 - 9 . doi:10.1161/CIRCULATIONAHA.111.084467   pmid:22474264 . OpenUrl
• ↵ Saarto T, Wiffen PJ. Antidepressants for neuropathic pain: a Cochrane review. J Neurol Neurosurg Psychiatry 2010 ; 357 : 1372 - 3 . doi:10.1136/jnnp.2008.144964   pmid:20543189 . OpenUrl

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here .

Loading metrics

Open Access

Peer-reviewed

Research Article

The Influence of Sex Steroids on Structural Brain Maturation in Adolescence

* E-mail: [email protected]

Affiliations Institute of Psychology, Brain and Development Lab, Leiden University, Leiden, The Netherlands, Leiden Institute for Brain and Cognition, Leiden, The Netherlands, Brain and Cognition, University of Amsterdam, Amsterdam, The Netherlands

Affiliations Institute of Psychology, Brain and Development Lab, Leiden University, Leiden, The Netherlands, Leiden Institute for Brain and Cognition, Leiden, The Netherlands

Affiliations Institute of Psychology, Brain and Development Lab, Leiden University, Leiden, The Netherlands, Leiden Institute for Brain and Cognition, Leiden, The Netherlands, Department of Developmental Psychology, University of Amsterdam, Amsterdam, The Netherlands

• P. Cédric M. P. Koolschijn, 
• Jiska S. Peper, 
• Eveline A. Crone

• Published: January 8, 2014
• https://doi.org/10.1371/journal.pone.0083929
• Reader Comments

Puberty reflects a period of hormonal changes, physical maturation and structural brain reorganization. However, little attention has been paid to what extent sex steroids and pituitary hormones are associated with the refinement of brain maturation across adolescent development. Here we used high-resolution structural MRI scans from 215 typically developing individuals between ages 8–25, to examine the association between cortical thickness, surface area and (sub)cortical brain volumes with luteinizing hormone, testosterone and estradiol, and pubertal stage based on self-reports. Our results indicate sex-specific differences in testosterone related influences on gray matter volumes of the anterior cingulate cortex after controlling for age effects. No significant associations between subcortical structures and sex hormones were found. Pubertal stage was not a stronger predictor than chronological age for brain anatomical differences. Our findings indicate that sex steroids are associated with cerebral gray matter morphology in a sex specific manner. These hormonal and morphological differences may explain in part differences in brain development between boys and girls.

Citation: Koolschijn PCMP, Peper JS, Crone EA (2014) The Influence of Sex Steroids on Structural Brain Maturation in Adolescence. PLoS ONE 9(1): e83929. https://doi.org/10.1371/journal.pone.0083929

Editor: Bogdan Draganski, Centre Hospitalier Universitaire Vaudois Lausanne - CHUV, UNIL, Switzerland

Received: July 24, 2013; Accepted: November 8, 2013; Published: January 8, 2014

Copyright: © 2014 Koolschijn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: This work was supported by Netherlands Organization for Scientific Research (NWO) Innovational research grant 451-10-007(JSP), and an European Research Council (ERC) starting grant 2010-StG-263234(EAC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Adolescence is a highly important transition phase between childhood and adulthood, marked by significant physical, social, cognitive and emotional changes [1] . Puberty is roughly characterized as the onset of adolescence between ages 9–14 (approximately 1–2 years earlier in girls than in boys) and represents the period in which reproductive capacity is achieved and phenotypic sexual maturity attained [2] . Puberty starts with pulsatile secretion of luteinizing hormone (LH) and the gonadotropin follicle-stimulating hormone (FSH). These hormones stimulate gonadal growth and gonadal hormone secretion and increase more than 30-fold in boys and 100-fold in girls [3] . This major hormonal change occurs as a result of activation of the hypothalamic-pituitary-gonadal (HPG) axis, causing gonadal maturation and production of sex steroids, most notably testosterone in boys and estradiol in girls. This process is termed gonadarche, and is followed by the activation of the growth axis leading to well known growth spurts and changes in body composition in puberty [1] , [4] , [5] .

Besides clearly visible physical changes, puberty also reflects a period of structural brain reorganization and pruning of neuronal circuits in the brain [6] , [7] . Sex steroids are thought to play an additional role in the refinement of brain maturation during puberty [8] .

While it is known that these hormonal increases are associated with a cascade of temperamental and behavioral changes (more risk-taking, social and exploratory behavior) [9] , the relationship between the levels of circulating gonadal hormones and brain morphology is not yet well understood.

Only recently studies started to examine the association between circulating sex steroids and brain gray matter in adolescence, with the majority of studies focusing on testosterone. Associations between testosterone levels and brain maturation vary widely between brain regions, morphological parameters (i.e. volume, cortical thickness, surface area) and sex. High circulating testosterone levels have been associated with smaller hippocampal and larger amygdala volumes [10] , larger amygdala volumes in females only [11] , and larger hypothalamic volumes in boys [10] . Studies reporting on the association of cortical thickness and testosterone demonstrated thicker limbic and occipital cortices with higher levels of testosterone in boys, but the opposite in girls [12] . Finally, in a longitudinal study higher levels of testosterone were related to thinning in the left dorsolateral prefrontal cortex, and primarily in portions of the left cingulate cortex in boys, whereas in girls there was a positive to negative association with testosterone in the right somatosensory cortex [13] . Thus, the findings on the relation between brain development and testosterone show inconclusive evidence and differ depending on sample size and age-range to detect differences.

With respect to estradiol, two studies found higher levels in early pubertal girls to be associated with a larger parahippocampus and uncus volumes [10] , greater gray matter density in middle frontal-, inferior temporal-, and middle occipital gyri, but lower regional gray matter density in decreases within prefrontal, parietal and middle temporal areas [14] . Thus, the relation with estradiol is much less studied and the differences reported are based on relatively small samples with small age-ranges.

While these studies do not show converging evidence of the direction of how sex steroids influence maturation of brain structures, it is clear that there are sex-specific associations between sex hormones and (sub)cortical brain areas which may vary over time. Next to sex steroids, the pituitary hormone LH -the hormonal precursor to the production of sex steroids- has also been implicated in brain maturation in very early stages of puberty [15] . Indeed, from both animal and human research it is known that LH receptors are found throughout the brain, including the parietal cortex [16] , [17] . However, it is still unknown if and how circulating LH levels exert their effects on cerebral gray matter across a wider age-range.

The aim of the current study was to assess the association between testosterone, estradiol, LH and (sub)cortical brain volumes, cortical thickness and surface area in a large Dutch sample (N = 215). We also selected specific regions of interest based on their relevance in functional brain maturation studies in adolescence [18] , including the anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), the inferior frontal gyrus (IFG) and orbitofrontal cortex (OFC). For example, fMRI studies of executive function have demonstrated increased recruitment of DLPFC and ACC from childhood to adulthood [19] . In addition, increased activity of OFC in adults relative to children and adolescents has been associated with a more matured pattern of self-regulatory processes [20] .

In a seminal study by Raznahan et al. [21] stepwise effects of androgen receptor transcriptional activity across adolescence were associated with cortical thinning in the inferior frontal gyrus (IFG), a region critically involved in executive functions such as inhibition. Specifically, girls with high androgen function demonstrated a significantly thinner IFG volume at age 22 years than at age 9 years compared to girls with low function or boys.

Evidence from genetic endocrine disorders such as familial male precocious puberty (a rare disorder with selective androgen excess) and Klinefelter syndrome (androgen insufficiency, in which males possess one extra X-chromosome) suggests an association between thinner DLPFC and high and low levels of testosterone respectively during adolescence [22] . In females with Turner syndrome (a genetic disorder characterized by partial or complete absence of one of the two X chromosomes), aberrant activation patterns have been reported for a.o. DLPFC [23] . Finally, in young adults, circulating levels of estradiol have been associated with thinning of the inferior frontal gyrus irrespective of sex [24] . We hypothesized that increasing levels of testosterone and estradiol would primarily be related with maturation (i.e. thinning or smaller volumes) of these frontal brain regions [12] , [13] .

Finally, we also explored associations of pubertal stage, as assessed by self-report with the Pubertal Development Scale (PDS; [25] ), and brain anatomy, to explore whether pubertal stage is a stronger predictor than chronological age.

Participants

A total of 215 right-handed participants between ages 8–25 were recruited from local schools and advertisement and included in this study. All participants had normal intelligence (M 109.31, SD 10.78; approximated using block design and similarities of the WISC-III for children up to 16 years of age and of the WAIS-IV from 16 years and older; Table 1 ) Participants had no self-reported history of neurological or psychiatric disorders, chronic illness, learning disabilities, or use of medicines known to affect nervous system functioning. Participants and primary caregivers (for minors) gave written informed consent for the study. Adults received fixed payment for participation, whereas children and their parents received presents and travel reimbursement. The internal review board from the Leiden University Medical Center approved the study.

• PPT PowerPoint slide
• PNG larger image
• TIFF original image

https://doi.org/10.1371/journal.pone.0083929.t001

Pubertal Measures

Puberty developmental scale (pds)..

The Pubertal Development Scale [25] was completed by all participants up to the 18 years of age. At a 4-points scale, participants had to indicate whether secondary sexual characteristics had: 1) not yet started to develop, 2) were showing the first signs, 3) were showing very clear development or 4) had already finished developing [26] . Puberty Category Scores were subsequently calculated and were based on body hair growth, voice change and facial hair growth for boys, and body hair growth, breast development and menarche for girls, leading to five categories: pre-pubertal, early pubertal, mid-pubertal, late pubertal and post-pubertal ( Table 1 ).

Sex steroids.

Boys and girls collected their saliva and urine at home, directly after waking up. Participants were instructed not to eat or brush their teeth before collecting saliva. It is most desirable to enroll girls during a specific period during the menstrual cycle to control for hormonal fluctuations, but most neuroimaging studies rarely take menstrual phase into account due to practical considerations. Here post-menarcheal girls collected saliva samples on the same day within the early follicular phase of the menstrual cycle (day 7), when hormone levels (e.g., progesterone) are relatively low [4] , [27] . Similarly, girls using oral contraceptives (n = 6) collected a saliva sample on the last day within their stopping period (day 7). Girls using contraceptives without a stopping period, such as hormonal intrauterine devices (e.g. Mirena), were excluded from participating in this study. All results remained similar with exclusion of girls using contraceptives; therefore, all results reported here include the whole sample.

The saliva samples of boys and girls were assayed for testosterone and estradiol levels at the Department of Clinical Chemistry of the VU Medical Center. The lower limit of detection was 4 pmol/L for testosterone, and 0.1 pg/ml for estradiol. Salivary testosterone was determined by isotope dilution–online solid phase extraction liquid chromatography–tandem mass spectrometry [28] . Intra-assay coefficient of variation (CV) was 11% and 4%, at 10 and 140 pmol/L, respectively and inter-assay CV was 8% and 5%, at 31 and 195 pmol/L, respectively. Salivary estradiol was determined using an enzyme linked immunosorbent assay (ELISA; DRG-Instruments, Marburg, Germany). Inter-assay CV was 8% and 15% at 10 and 40 pg/L, respectively [29] . LH was determined in morning urine using highly sensitive immunometric assays (Luminiscention) detection limit 0.1 U/l, carried out by the endocrinological laboratory of Clinical Chemistry of the VU Medical Center in Amsterdam (Architect, Abbott Laboratories, Abbott Park, Illinois USA). Urinary LH levels were divided by creatinine level to correct for variations in urine excretion rate [15] . A creatinine correction has been demonstrated to enhance the detection of LH-surges [30] . Hormonal levels for each sex are displayed in Table 1 .

Data Acquisition

All participants were scanned on a 3-Tesla whole body Philips Achieva MRI system (Best, The Netherlands). High-resolution T1-weighted anatomical scan were obtained: 3D-T1-weighted scan: TR = 9.717 msec; TE = 4.59 msec, flip angle = 8°, 140 slices, .875×.875×1.2 mm, FOV = 224.000×168.000×177.333). All anatomical scans were reviewed and cleared by a radiologist.

Image Analysis

Cortical reconstruction and volumetric segmentation was measured automatically using FreeSurfer5.0 ( http://surfer.nmr.mgh.harvard.edu/ , [31] , [32] . Details of the surface-based cortical reconstruction and subcortical volumetric segmentation procedures have been extensively documented previously [31] – [34] . Briefly, the FreeSurfer pipeline performs motion correction on the T1-images, automatically removes non-brain tissues [34] , transforms volumetric data to a common atlas, performs intensity normalization and topology correction [33] , [35] and defines the boundaries of the gray/white matter and pial surface [31] , [32] . Volumetric subcortical segmentation and measurement was performed using automated procedures that have been validated as comparable in accuracy to much slower, labor-intensive manual tracing and labeling methods [33] , [36] . This procedure automatically classifies brain tissue into multiple distinct structures such as cerebral and cerebellar gray and white matter, cerebrospinal fluid (CSF), basal ganglia, and other subcortical structures. Using probabilistic information derived from a manually labeled training data set, this approach automatically assigns a neuroanatomical label to each voxel in the MRI volume. For the purposes of the current study, automated image surfaces and segmentations were inspected and screened for quality control but were not manually edited, in order to maintain the objectivity of results. Of note, large deformities such as failure to segment or include the entire brain were excluded from the study (N = 20, not included in Table 1 ). Intracranial volume was determined by a validated automated method known to be equivalent to manual intracranial volume estimation [37] .

Regions of interest (ROIs) were created based on their relevance in functional brain maturation in adolescence [18] . These regions were created based on combined labels from the Desikan–Killiany atlas [38] : ACC (rostral, caudal, posterior and isthmus parcellation); OFC (lateral and medial OFC parcellation); inferior frontal gyrus (IFG; pars opercularis, pars orbitalis and pars triangularis), DLPFC (middle frontal gyrus, inferior and middle frontal sulci). Gray matter volume (ml) and cortical thickness (mm) were automatically extracted.

Statistical Analyses

Testosterone and LH/creatinine levels were highly skewed and were log-transformed. All further analyses concerning levels of LH/creatinine were carried out on these log-transformed scores. As expected, there were substantial sex differences in testosterone levels ( F  = 125.6; p <.00001), therefore a Z-transformation was applied on the log-transformed testosterone levels: high scores on this testosterone distribution indicated high levels of testosterone relative to other individuals of the same sex [39] , [40] . All further analyses concerning levels of testosterone were carried out on these log-transformed, standardized scores of testosterone.

Age was positively associated with testosterone (whole sample: r = .62; p<.001; Males: r = .72, p<.001; Females: r = .53, p<.001), estradiol (whole sample: r = .23, p = .001; Males: r = .32, p = .002; Females: r = .13, p = .19), and LH (whole sample: r = .22; p = .003; Males: r = .18, p = .1; Females: r = .29, p = .018). To examine the inter-relations between sex steroids, partial correlations were calculated between hormone levels correcting for age. In males, testosterone levels showed a moderate association with estradiol levels (r = .23; p = .036), and with LH (r = .31; p = .005), but no association was found between estradiol and LH levels (r = .07; p = .51). In females, testosterone levels showed a moderate association with estradiol levels (r = .27; p = .009), and with LH (r = .36; p = .001), and also between estradiol and LH levels (r = .24; p = .025).

The cortical thickness data were averaged across participants in the spherical coordinate system after smoothing (FWHM 10 mm), so that surface areas with significant differences of mean cortical thickness differences and the different sex steroids levels could be overlaid in statistical difference maps (using t -statistics) for the whole sample and between boys and girls. Vertex-wise analyses were performed using a general linear model approach in QDEC. We addressed differences in cortical thickness for the whole sample and each hormone, with age as nuisance factor. Differences were reported as significant below a FDR corrected p-value of 0.05.

The volumes of all subcortical structures and ROIs were averaged across hemisphere within participants. Brain volume measures were corrected for intracranial volume as an estimate of head size, because head size in males is in general about 10% larger than in females [41] . Stepwise regression analyses were performed on the whole sample with age, sex, and pubertal hormone (testosterone, estradiol or LH; or a sex-by-hormone interaction-term) as predictors. The analyses were repeated within each sex separately. Due to the number of analyses, we corrected for multiple comparisons using a Bonferroni correction: α = .05/13ROIs = .0038.

To explore if pubertal stage is a stronger predictor than chronological on brain anatomy, we performed whole brain vertex-wise analyses and ROI analyses with pubertal stage (pre, early, mid, late and post) and age as a nuisance variable. In case of significant effects of pubertal stage, we tested the precise differences using Tukey post hoc tests.

Whole Brain Vertex-wise Analyses with Sex Steroids

In contrast with our hypothesis, there were no effects of sex steroids on cortical thickness and surface area (with age as nuisance variable and correction for multiple comparisons). Subsequent analyses with each hormone and age separately (corrected for multiple comparisons), revealed that there was significant overlap in brain regions that showed a correlation with testosterone or estradiol and age, but not LH, suggesting that the age-related difference were stronger than the hormone-related differences (for testosterone and estradiol, see Figure 1A,B ). Age-related thinning remained similar after correction for sex hormone levels (for testosterone see Figure 1C,D ) . These age-related findings have been reported in several other studies (e.g. [42] – [44] ). Next, we used the region-of-interest approach to examine the unique contribution of sex steroids after controlling for age effects.

A. Estradiol (pmol) related thinning. B. Testosterone (Zlog) related thinning. C. Age-related thinning corrected for testosterone levels (Zlog). D. Age-related thinning. FDR-corrected, p<.05 in all figures.

https://doi.org/10.1371/journal.pone.0083929.g001

Relationship between Brain Volumes and Sex Steroids

Testosterone..

Testosterone related effects, after controlling for age-related differences, were found in ACC and OFC gray matter volume. Specifically, we found that higher testosterone levels contributed to ACC (p = .008) and OFC (p = .026) gray matter volume maturation, i.e. additional volume reductions after controlling for age-related volume reductions (see Table 2A ). The sex-by-testosterone interaction was significant for the ACC after controlling for age (p<.001), but not for OFC (p = .25). To further explore possible sex differences, we repeated the analyses in each sex separately for both structures. These analyses showed that for males higher testosterone levels were related to smaller ACC gray matter volumes (p = .002; survived Bonferroni correction), but in females there was no such association (p>.5). The opposite was found for the OFC, such that higher testosterone levels in females were related to smaller OFC gray matter volumes (p = .023), but not in males (p>.4), but this effect did not survive Bonferroni correction.

https://doi.org/10.1371/journal.pone.0083929.t002

A significant effect of estradiol levels was found also in ACC gray matter volume, demonstrating smaller ACC gray matter volumes with higher estradiol levels after controlling for age-related effects (p = .01; see Table 2B ). The sex-by-estradiol interaction was not significant for the ACC after controlling for age (p = .35). Yet, to further explore possible sex differences, we repeated the analyses in each sex separately. These analyses showed that higher estradiol levels were associated with smaller ACC gray matter volume in males (p = .01), and in females (p = .049).

For total gray matter volume the sex-by-estradiol interaction was not significant (p = .088). Subsequent analyses revealed an association between estradiol and total gray matter volume in males after controlling for age (p = .018). However, none of the estradiol-brain volume associations survived Bonferroni correction.

We found a significant sex-by-LH interaction with total gray matter volume after controlling for age (p = .02; Table 2C ) . Follow-up analyses in males and females resulted in trend level associations with gray matter (Males: ß = 1.44; p = .062; Females: ß = −.122; p = .085). As the only earlier study on LH and brain structure found effects in early pubertal children [15] , we repeated the LH analyses by removing participants in advanced stages of puberty (i.e. mid, late and post puberty). No significant effects of LH on total gray matter were found after controlling for age.

There were no significant associations between DLPFC, IFG or subcortical structures and testosterone, estradiol or LH after controlling for age effects.

Pubertal Stage

To examine if pubertal stage is a stronger predictor than is chronological on brain anatomy, we performed whole brain vertex-wise analyses and ROI analyses with pubertal stage (pre, early, mid, late and post) with age as a nuisance variable.

There were no effects of pubertal stage based on PDS on cortical thickness and surface area (with age as nuisance variable and correction for multiple comparisons).

We used the GLM to examine the association with pubertal stage and our ROIs, here corrected for both intracranial volume and age, and Tukey post hoc tests to examine possible differences between pubertal stages. No significant effects were found for our subcortical structures or our custom ROIs, indicating that pubertal stage, based on self-report, is not a stronger predictor for brain anatomy than chronological age.

To compare our findings with two earlier studies [11] , [45] , we repeated our analyses and excluded the pre and post-puberty group, leaving three groups: early (N = 31, 18 Males), mid (N = 60, 24 Males) and late puberty (N = 36, 19 Males). Here we found an association between pubertal stage and inferior frontal gyrus (IFG) gray matter volume (F (2,137)  = 3.94; p = .033) independent of age, sex and intracranial volume. Tukey post hoc tests indicated that IFG volume was larger in early pubertal stages compared to late puberty (p = .025), but did not differ with mid puberty (p = .52) or between mid and late pubertal stages (p = .14).

The goal of this study was to examine the contributions of the sex steroids testosterone, estradiol and LH to structural brain maturation in a large Dutch sample with variability in both age and pubertal status. Two main effects were reported: 1) Our results indicate a sex-specific difference in testosterone related influences on gray matter volume of the anterior cingulate after controlling for age effects. Although other associations between sex steroids and brain anatomy were reported, these findings did not surive stringent Bonferroni correction. 2) Pubertal stage based on self-report was not a stronger predictor than chronological age for brain anatomy. The specific findings will be discussed below.

Testosterone

Circulating testosterone levels were inversely related to gray matter volume in the ACC and OFC. There were sex-specific differences in testosterone-brain associations, similar to the study by Bramen et al (2012) where sex-specific differences were reported in left inferior parietal lobule, middle temporal gyrus, calcarine sulcus, and right lingual gyrus. Here, testosterone levels in males, but not in females, were strongly related to a smaller ACC gray matter volume after controlling for age-related volume reduction. Our effects of testosterone mimic prior findings from a longitudinal developmental neuroimaging study in which ACC cortical thinning was related to higher levels of testosterone in males only [13] .

Decreased gray matter volumes during puberty and adolescence have been associated with the loss of unneeded connections (synaptic pruning; [46] ), decreases of dendritic spine density and elimination of synaptic spines starting during puberty [47] , and the encroachment of continued white matter growth which normally extends into the 4th decade ( [48] [49] – [51] . Interestingly, in a recent study cultured nerve cells were exposed to high levels of testosterone, and it was found that it triggered programmed cell death, but not with low or normal levels of testosterone or estradiol [52] . Testosterone is key to the development, differentiation and growth of cells, but it was found that very high levels result in opposite effects. However, it would be too simplistic to suggest that testosterone levels are the only basis for these volumetric sex differences. Currently, the mechanism(s) through which testosterone and estradiol direct neural changes in the brain are largely unknown [53] .

On a behavioral level, in numerous studies on animals, a strong correlation between testosterone levels and aggression has been reported (e.g. [54] ), while in humans testosterone is linked to dominance and competitiveness, in general, more than to aggression (e.g. [55] ). During adolescence, competitiveness and increased risk taking behavior is characteristic of males [56] . In a longitudinal study in adolescent boys, a positive correlation was found between testosterone and different forms of aggressive and delinquent behavior [57] . Furthermore, aggressive and defiant behavior has been associated with smaller ACC volumes [58] and thickness [59] in pubertal boys (ages 6–18). Speculatively, our finding of smaller ACC volumes in males and increased levels of testosterone may predispose to more competitive and dominant behaviors characteristic for adolescence.

In females we found an association between higher testosterone levels and smaller OFC gray matter volume after correcting for age (but not after Bonferroni correction). The OFC has been thought to play a crucial role in optimal decision-making under risk and value-based decision-making [60] . Increased risk-taking behavior during adolescence has been associated with slow development of frontal regions, necessary for top-down control and inhibitory processes, as compared to earlier maturation of subcortical brain structures related with reward and sensation seeking [20] , [61] . The relationship between testosterone and OFC is demonstrated by studies measuring endogenous testosterone levels showing reduced OFC involvement during impulse control [62] , sex-specific differences in risk-taking behavior and OFC morphology [63] and reduced OFC-amygdala functional coupling in a testosterone administration study. [64] Taken together, these findings may serve as a potential explanation for sex differences in decision-making and risk-taking behavior during adolescence.

Similar to the effects of testosterone, estradiol showed a negative association with ACC gray matter volume in males and females, though the sex-by-estradiol interaction was not significant. Estradiol levels were inversely related to cerebral gray matter volume in males, but not in females. It should be noted that the enzyme aromatase converts a small portion of testosterone into estradiol [65] , which may in part account for our current findings, despite low correlations between these pubertal hormone levels. Although evidence for the relation between estradiol and gray matter development during adolescence is scarce, earlier studies (with smaller sample sizes and different methodologies) reported decreased gray matter density in frontal and parietal regions in females with higher estradiol levels [10] , [14] . Thus, the current results show that in the absence of sex-differences in estradiol levels, there is a male-specific effect of estradiol on ACC and cerebral gray matter. However, caution must be taken with interpreting our findings, as estradiol-brain effects did not remain statistical significance when correcting for multiple comparisons.

Luteinizing Hormone

Here we report a significant sex-by-LH interaction for cerebral gray matter in humans. As can be seen in Table 2C , males seem to show a slight positive association with cerebral gray matter while it is the opposite in females; but none of these findings reached statistical significance. Although LH receptors are distributed throughout the brain, including hippocampus, cortex, area postrema, hypothalamus and cerebellum [16] , [17] , the effects of LH on brain tissue may be too small to detect differences at a global and local level. The only earlier study on LH and brain structure demonstrated positive effects of LH in early pubertal children on white matter [15] . That study was specifically designed to assess sex steroids in a homogeneous sample of nine-year old twin pairs (N = 104 individuals). Here, our focus was on the interplay of sex steroids and structural brain development across the wider range of adolescence. Nevertheless, we looked into the relationship between LH and brain morphology in pre, early, and mid-puberty, but no evidence for an association between LH and gray matter was found.

Review of Non-significant Sex-steroid Findings

No significant associations between pubertal hormone levels and hippocampal and amygdalar, or other subcortical brain structures were found. This was unexpected, because the hippocampus and amygdala are both rich in testosterone and estrogens receptors [66] and testosterone administration in females leads to more male-typical behavior [55] . Furthermore, positive associations of testosterone have been reported in hippocampal and amygdalar volumes in puberty [10] , [11] . The absent findings between sex steroids and subcortical brain morphology might be explained by a number of factors. First, age-related brain changes may outweigh hormonal effects, especially in samples with a relatively large age-range. Second, we aimed to assess biological variation in estradiol levels, rather than menstrual cycle variation. Hence, estradiol levels in our sample were relatively low in girls, because saliva was collected during the early follicular phase of their menstrual cycle, when hormone levels are low [27] . A few studies in humans have started to look into the effects of menstrual cycle phase and brain morphology. Although, sample sizes are small, there is some evidence of phase-related changes in amygdala and cerebral gray matter volume [67] , [68] . This emphasizes the need to be precise in data collection during the menstrual cycle. Third, subcortical structures may mature more pronounced under the influence of fetal testosterone. In a recent study, fetal testosterone levels of boys aged 8–11 predicted differences in gray matter volume in some sexual dimorphic brain structures [69] .

Interestingly, functional brain imaging studies reported relations between testosterone levels and brain activation mainly in subcortical areas, such as the ventral striatum [70] . It will be interesting to combine these approaches in future studies, and examine the role of stable versus fluctuating levels of sex steroids on brain structure, function and behavior.

Pubertal Stage versus Chronological Age

Besides the effects of sex-steroids we also looked into the contribution of pubertal stage as a predictor of brain anatomy compared to chronological age. We did not find any differences between groups on the whole brain analyses, or the ROI approach when all pubertal stages were included. This is in line with Bramen and colleagues, who reported associations in amygdala volume in boys with pubertal stage, but these effects were lost after age correction [11] . In two independent studies, pubertal stage was found to be a better predictor than chronological age in females for the left amygdala [45] , and for the right amygdala and bilateral cortex [11] . Here we could not replicate these findings, even when we removed the pre and post-puberty group from the analyses. However, when only early, mid and late pubertal groups were included in the analyses there was an effect of pubertal stage on IFG volume, such that early pubertal groups had larger volumes compared to late pubertal groups independent of age, sex and intracranial volume. This finding complements earlier reports demonstrating smaller IFG volumes in girls with increased estradiol levels [14] , and in part Witte et al. showing smaller IFG volumes with high levels of testosterone, but larger volumes for high levels of estradiol in young adults [24] .

Methodological Considerations

One may argue that the age distribution of our sample could hamper detection of some hormone-related differences, especially on a whole brain level. In the current study, age-related effects outweighed hormonal effects (see Table 2 and Figure 1 ). The advantage of the current study is that we were able to examine sex hormone-related influences across adolescence. However, studies with a narrow age-range may be more suitable to explicitly disentangle sex steroids and age effects. In addition longitudinal designs are needed to assess hormonal and brain changes over time, and confirm reliability of hormonal assessment during puberty.

In the current study, hormones were collected immediately after waking up for several reasons: First, LH shows a day-night rhythm, while testosterone and estradiol show diurnal rhythms. Second, to reduce saliva contamination due to for example food or drinks at a later time point. Third, this method was used to reduce the effort for the participants and parents, and increase compliance. However, during puberty there is a shift in testosterone peak levels, from early morning in pre- and mid-puberty to the afternoon in late puberty [71] , [72] . Furthermore, diurnal rhythms of testosterone are more stable in pubertal boys compared to girls [73] . Estradiol shows a similar diurnal pattern in girls, with high levels in the morning and low levels in the evening, but several studies have shown that the diurnal pattern for estradiol diminishes after menarche and is lost between 1–2 years postmenarche [71] , [74] . These fluctuations in diurnal patterns may have influenced our results. In future studies it will be important to collect multiple saliva samples (across multiple days) to look at influence of diurnal rhythms and the relation with structural brain development.

Conclusions

In sum, sex steroids are associated with cerebral gray matter morphology in a sex specific manner. Specifically, our results indicate age independent, sex-specific differences in testosterone related influences on gray matter volumes of the anterior cingulate. The functional relevance of these hormone-related findings to our understanding of typical brain development could be vast numerous. For example, the influence of sex steroids on human brain structure not only gives important insights into the etiology of healthy brain maturation, but can also provide valuable information for the development of neuropsychiatric illnesses with a skewed sex ratio [6] , [75] . In future studies, it is important to reach consensus on standardized measures for hormone collection to reduce unnecessary between-study variability. Second, to understand the functional relevance of hormone-related brain maturation, future studies should effectively combine behavioral, functional and hormonal measurements to disentangle the structure–function-hormone relationship and its development during the transition into adulthood.

Author Contributions

Conceived and designed the experiments: PCMPK JSP EAC. Performed the experiments: PCMPK JSP EAC. Analyzed the data: PCMPK JSP. Contributed reagents/materials/analysis tools: PCMPK JSP. Wrote the paper: PCMPK JSP EAC.

• View Article
• Google Scholar
• 51. Yakovlev PI, Lecours AR (1967) The myelogenetic cycles of regional maturation of the brain. In: Minkowski A, editor. Regional Development of the Brain in Early Life. Boston: Blackwell. 3–70.
• 63. Peper JS, Koolschijn PC, Crone EA (2013) Development of Risk Taking: Contributions from Adolescent Testosterone and the Orbito-frontal Cortex. J Cogn Neurosci In Press.