Ergogenic and metabolic effects of oral glucocorticoid intake during repeated bouts of high-intensity exercise

Glucocorticoids and physical performance: A systematic review with meta-analysis of randomized controlled trials

Introduction

This systematic review with meta-analysis investigates the effect of glucocorticoids on maximal and submaximal performance in healthy subjects.

Methods

We searched for randomised controlled trials investigating the effect of glucocorticoids on physical performance in Web of Science, Scopus, Medline, Embase and SportDiscus in March 2021. Risk of bias was assessed with the revised Cochrane Collaboration Risk of Bias Tool (RoB2). Data from random effect models are presented as standardized difference in mean (SDM) with 95% confidence interval. We included 15 studies comprising 175 subjects.

Results

Two studies had high risk of bias. Glucocorticoids had a small positive effect on maximal physical performance compared to placebo (SDM 0.300, 95% CI 0.080 to 0.520) and the SDM for the 13 included comparisons was not heterogeneous (I2= 35%, p = 0.099). Meta regression found no difference in the effect of acute treatment vs. prolonged treatment or oral ingestion vs. inhalation (p > 0.124). In stratified analysis prolonged treatment (SDM 0.428, 95% CI 0.148 to 0.709) and oral ingestion (SDM 0.361, 95% CI 0.124 to 0.598) improved physical performance. Glucocorticoids improved aerobic performance (SDM 0.371, 95% CI 0.173 to 0.569) but not anaerobic performance (p = 0.135). Glucocorticoids did not change energy expenditure during submaximal performance (SDM 0.0.225 95% CI -0.771 to 0.112).

Discussion

This study indicates that glucocorticoids improves maximal performance and aerobic performance. Glucocorticoids did not affect the energy expenditure during submaximal performance. The conclusions are based on relatively few subjects leading to limited statistical power and uncertain estimates. Still, these results are consistent and should be of interest to WADA and anyone concerned about fair play.

Systematic Review Registration

Open Science Framework 2021-04-29 (https://osf.io/fc29t/).

Prevalence of Prohibited Substance Use and Methods by Female Athletes: Evidence of Gender-Related Differences

To achieve optimal sports performances, women and men may show specific doping practices because of the physiological and psychological gender differences, but there are few data on this topic. Here, we report the apparent use of prohibited substances and methods by female athletes based on analyses of the doping tests collected by the French Anti-Doping Agency from 2013 to 2019. We compared the frequency of use and the ergogenic and side effects to those of their male counterparts. The results revealed lower use of prohibited substances in female vs. male athletes, with significantly fewer anabolic agents, hormone and metabolic modulators, and cannabinoids. Gender specificity in utilization of substance classes was also shown. Relatively lower use of hormone modulators and cannabinoids and higher use of beta-2 agonists, diuretics and glucocorticoids were found in the woman cohort compared with men cohort, combined with the different choice of substances, possibly because of the altered ergogenic and/or side effects. However, no impact due to gender regarding the sports disciplines was observed, with both women and men showing similar use of anabolic agents, mainly in the anaerobic sports, and EPO and corticoids, mainly in endurance or mixed sports. Further studies are needed to put these French data into a global perspective, comparing uses across countries and exploring possible new developments in the fight against doping in women.

Effect of Glucocorticoids on Athletic Performance: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the effects of glucocorticoids in enhancing athletic performance.

DESIGN

At least 2 independent reviewers conducted study selection and extracted demographic and outcome data. Relevant outcomes were stratified by administration time frame and the specific type of drug used. Study quality was assessed using the Cochrane Risk-of-Bias tool and the Cochrane Grading of Recommendations Assessment Development and Education scale. Where appropriate, meta-analyses were performed. Data sources: Embase, MEDLINE, and SPORTDiscus were searched from their beginning to April 2020.

PARTICIPANTS

Participants of any sex and training status aged 18 to 65 years were included.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Any type of published randomized controlled trial (RCT) that examined any enhancement in sport as well as aerobic, anaerobic, or body compositional parameters for glucocorticoids compared with placebo.

RESULTS

There is low-to-moderate evidence suggesting that the administration of glucocorticoids may be more beneficial than placebo in enhancing athletic performance. short-term administration of glucocorticoids significantly improved time to exhaustion, maximal force, and total distance travelled. By contrast, acute administration of glucocorticoids predominantly yielded no changes to athletic performance, except for reductions in total work and maximal power output.

CONCLUSIONS

Although there is evidence suggesting glucocorticoids have ergogenic effects, these improvements may differ depending on the specific type of drug, dose, and the administration time frame and are also limited by small sample sizes. Therefore, there is a need for large, high-quality RCTs as this may influence future doping policy and athlete care.

A novel approach to improve detection of glucocorticoid doping in sport with new guidance for physicians prescribing for athletes

The systemic effect of glucocorticoids (GCs) following injectable routes of administration presents a potential risk to both improving performance and causing harm to health in athletes. This review evaluates the current GC antidoping regulations defined by the World Anti-Doping Agency and presents a novel approach for defining permitted and prohibited use of glucocorticoids in sport based on the pharmacological potential for performance enhancement (PE) and risk of adverse effects on health. Known performance-enhancing doses of glucocorticoids are expressed in terms of cortisol-equivalent doses and thereby the dose associated with a high potential for PE for any GC and route of administration can be derived. Consequently, revised and substance-specific laboratory reporting values are presented to better distinguish between prohibited and permitted use in sport. In addition, washout periods are presented to enable clinicians to prescribe glucocorticoids safely and to avoid the risk of athletes testing positive for a doping test.

Moderate Aerobic Exercise Training Prevents the Augmented Hepatic Glucocorticoid Response Induced by High-Fat Diet in Mice

Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated with the development of obesity and metabolic syndrome. However, it is not understood if obesity alters the tissue glucocorticoid receptor (GR) response, and moreover whether a moderate aerobic exercise prevents the alteration in GR response induced by obesity. Methods: To evaluate the GR response in obese mice, we fed C57BL6J mice with a high-fat diet (HFD) for 12 weeks. Before mice were sacrificed, we injected them with dexamethasone. To assess the exercise role in GR response, we fed mice an HFD and subjected them to moderate aerobic exercise three times a week. Results: We found that mice fed a high-fat diet for 12 weeks developed hepatic GC hypersensitivity without changes in the gastrocnemius or epididymal fat GR response. Therefore, moderate aerobic exercise improved glucose tolerance, increased the corticosterone plasma levels, and prevented hepatic GR hypersensitivity with an increase in epididymal fat GR response. Conclusion: Collectively, our results suggest that mice with HFD-induced obesity develop hepatic GR sensitivity, which could enhance the metabolic effects of HFD in the liver. Moreover, exercise was found to be a feasible non-pharmacological strategy to prevent the deregulation of GR response in obesity.

Review of WADA Prohibited Substances: Limited Evidence for Performance-Enhancing Effects

The World Anti-Doping Agency is responsible for maintaining a Prohibited List that describes the use of substances and methods that are prohibited for athletes. The list currently contains 23 substance classes, and an important reason for the existence of this list is to prevent unfair competition due to pharmacologically enhanced performance. The aim of this review was to give an overview of the available evidence for performance enhancement of these substance classes. We searched the scientific literature through PubMed for studies and reviews evaluating the effects of substance classes on performance. Findings from double-blind, randomized controlled trials were considered as evidence for (the absence of) effects if they were performed in trained subjects measuring relevant performance outcomes. Only 5 of 23 substance classes show evidence of having the ability to enhance actual sports performance, i.e. anabolic agents, β2-agonists, stimulants, glucocorticoids and β-blockers. One additional class, growth hormone, has similar evidence but only in untrained subjects. The observed effects all relate to strength or sprint performance (and accuracy for β-blockers); there are no studies showing positive effects on reliable markers of endurance performance. For 11 classes, no well-designed studies are available, and, for the remaining six classes, there is evidence of an absence of a positive effect. In conclusion, for the majority of substance classes, no convincing evidence for performance enhancement is available, while, for the remaining classes, the evidence is based on a total of only 266 subjects from 11 studies.

Exhaled volatile organic compounds as markers for medication use in asthma

INTRODUCTION

Asthma is a heterogeneous condition, characterised by chronic inflammation of the airways, typically managed with inhaled bronchodilators and corticosteroids. In the case of uncontrolled asthma, oral corticosteroids (OCSs) are often prescribed. Good adherence and inhalation technique are associated with improved outcomes; however, it is difficult to monitor appropriate drug intake and effectiveness in individual patients. Exhaled breath contains thousands of volatile organic compounds (VOCs) that reflect changes in the body's chemistry and may be useful for monitoring drug pharmacokinetics/pharmacodynamics. We aimed to investigate the association of exhaled VOCs in severe asthma patients from the U-BIOPRED cohort (by gas chromatography coupled with time-of-flight mass spectrometry) with urinary levels of salbutamol and OCSs (by liquid chromatography coupled with high-resolution mass spectrometry).

METHODS

Samples were collected at baseline and after 12-18 months of follow-up. Statistical analysis was based on univariate and multivariate modelling, followed by area under the receiver operating characteristic curve (AUC) calculation. Results were verified through longitudinal replication and independent validation.

RESULTS

Data were available for 78 patients (baseline n=48, replication n=30 and validation n=30). Baseline AUC values were 82.1% (95% CI 70.4-93.9%) for salbutamol and 78.8% (95% CI 65.8-91.8%) for OCS. These outcomes could be adequately replicated and validated. Additional regression analysis between qualified exhaled VOCs and urinary concentrations of salbutamol and prednisone showed statistically significant correlations (p<0.01).

CONCLUSION

We have linked exhaled VOCs to urinary detection of salbutamol and OCSs. This merits further development of breathomics into a point-of-care tool for therapeutic drug monitoring.

Corticosterone rapidly improves the endurance of high-intensity exercise (swimming) via nongenomic mechanisms in mice

BACKGROUND

Glucocorticoids (GCs) take a pivotal role during the stress response. Some clinical studies suggest short-term GCs intake improves exercise endurance. However, whether the rapid nongenomic effects of GCs are involved in acute exercise is still unknown. Here, we aimed to reveal the potential nongenomic effects of GCs in skeletal muscle of mice during exercise.

METHODS

Adrenalectomized mice subjected to a weight-loaded forced swim were used for detecting the changes of time to exhaustion. Corticosterone (CORT) and other drugs were injected via the coccygeal vein before swimming. After exhaustion, the injury of skeletal muscle, nitric oxide generation, blood glucose and lactic acid were determined.

RESULTS

The results demonstrated that CORT rapidly extended the time to exhaustion within 30 min (~30%), which could not be abolished by glucocorticoid receptor antagonist RU486. Pretreatment with the nitric oxide synthesis inhibitor L-NAME prior to CORT administration further increased exercise tolerance compared to the increase caused by CORT alone. Moreover, CORT contributed to protecting skeletal muscle from injury and maintaining blood glucose.

CONCLUSIONS

Considered together, our results suggest that GCs rapidly improve exercise tolerance via its nongenomic mechanism, which is associated with the inhibition of nitric oxide generation. Pretreatment of GCs may be helpful to enhance exercise tolerance during acute exercise.

Analgesics and Sport Performance: Beyond the Pain-Modulating Effects

Analgesics are used widely in sport to treat pain and inflammation associated with injury. However, there is growing evidence that some athletes might be taking these substances in an attempt to enhance performance. Although the pharmacologic action of analgesics and their use in treating pain with and without anti-inflammatory effect is well established, their effect on sport performance is debated. The aim of this review was to evaluate the evidence of whether analgesics are capable of enhancing exercise performance and, if so, to what extent. Paracetamol has been suggested to improve endurance and repeated sprint exercise performance by reducing the activation of higher brain structures involved in pain and cognitive/affective processing. Nonsteroidal anti-inflammatory drugs affect both central and peripheral body systems, but investigation on their ergogenic effect on muscle strength development has provided equivocal results. The therapeutic use of glucocorticoids is indubitable, but clear evidence exists for a performance-enhancing effect after short-term oral administration. Based on the evidence presented in this review article, the ergogenic benefit of analgesics may warrant further consideration by regulatory bodies. In contrast to the aforementioned analgesics, there is a paucity of research on the use of opioids such as tramadol on sporting performance.

LEVEL OF EVIDENCE

III.

The effect of acute and short term glucocorticoid administration on exercise capacity and metabolism

OBJECTIVES

Glucocorticoids (GC) are commonly used in the treatment of inflammatory conditions. Chronic GC administration has severe side effects that can decrease exercise capacity and, as a result performance. The side effects of acute (single dose) and short term (<7 days) GC administration are less severe, therefore the impact on exercise performance is unclear. Consequently, it is of interest to determine the influence of acute and short term GC administration on exercise capacity and performance and investigate the relationship with metabolism.

DESIGN

Review article.

METHODS

Included in the review were studies with healthy volunteers that reported exercise capacity and performance outcomes following acute and short term GC ingestion. Additionally, the relationship of exercise, GC ingestion and metabolism was investigated.

RESULTS

Acute GC treatment appears to have minimal effects on exercise performance at intensities between 60 and 90% of VO_2max. Short term GC treatment improved performance in the majority of studies at various exercise intensities. In general, blood glucose values increased whilst insulin and lactate values remained unchanged following GC administration. However, inconsistencies in metabolic results are present and may be due to variations in exercise protocols and the type and dosage of drug treatments.

CONCLUSIONS

Acute GC administration has a minimal effect on exercise capacity and performance while short-term GC administration is likely to improve performance. Future studies should focus on the effects of GC on exercise performance and exercise metabolism during and post exercise to determine the effects on exercise capacity.

Immunosuppressants and Male Reproduction

Prolonged use of immunosuppressant medications is occasionally seen in infertile men with chronic inflammatory conditions; autoimmune disorders; or an organ or hematopoietic stem cell transplant. Chronic inflammation impacts negatively on male reproductive endpoints, so immunosuppressant therapy can produce improvements. Corticosteroids have been used to treat antisperm antibodies and even as an empirical treatment for male infertility in general. Trials of these methods have provided mixed results on semen quality and fertility, with improvement, no change and negative effects reported by different investigators. In a substantial number of observational studies, patients on long-term therapy with prednisone for chronic inflammatory disease, testosterone levels were lower compared to untreated controls, though randomized controlled trials have not been conducted. Similarly decreases in testosterone have been reported in men receiving corticosteroids to minimize transplant rejection; however, most were treated with multiple immunosuppressive medications that may have contributed to this effect. A large number of trials of healthy men treated with corticosteroids have shown some disruption in reproductive hormone levels, but other studies reported no effect. Studies in monkeys, rats (at human equivalent dose), cattle, sheep, and horses have shown endocrine disruption, including low testosterone with dexamethasone treatment. Of the cytostatic immunosuppressives, which have high potential for cellular damage, cyclophosphamide has received the most attention, sometimes lowering sperm counts significantly. Methotrexate may decrease sperm numbers in humans and has significant negative impacts in rodents. Other chemotherapeutic drugs used as immunosuppressants are likely to impact negatively on male fertility endpoints, but few data have been collected. The TNF-α Inhibitors have also received little experimental attention. There is some evidence that the immunophilin modulators: cyclosporine, sirolimus, and everolimus cause endocrine disruption and semen quality impairment. As we review in this chapter, results in experimental species are concerning, and well-designed studies are lacking for the effects of these medications on reproductive endpoints in men.

Glucocorticoid administration in athletes: Performance, metabolism and detection

It is generally acknowledged in the sporting world that glucocorticoid (GC) use enhances physical performance. This pharmacological class is therefore banned by the World Anti-Doping Agency (WADA) in in-competition samples after systemic but not local (defined as any route other than oral, intravenous, intramuscular or rectal) administration, which thus allows athletes to use GCs for therapeutic purposes. According to the 2016 WADA list, the urine reporting level for all GCs is set at 30ng/ml to distinguish between the authorized and banned routes of administration. The actual data on the ergogenic effects of GC intake are nevertheless fairly recent, with the first study showing improved physical performance with systemic GC administration dating back only to 2007. Moreover, the studies over the last decade coupling ergogenic and metabolic investigations in humans during and after GC intake have shown discrepant results. Similarly, urine discrimination between banned and authorized GC use remains complex, but it seems likely to be improved thanks to new analytical studies and the inclusion of the authorized GC uses (local routes of administration and out-of-competition samples) in the WADA monitoring program. In this review, we first summarize the current knowledge on the ergogenic and metabolic GC effects in humans during various types of exercise. We then present the antidoping legislation and methods of analysis currently used to detect GC abuse and conclude with some practical considerations and perspectives.