The asthmatic athlete: inhaled Beta-2 agonists, sport performance, and doping

Systemic adverse events and all-cause mortality following same-session bilateral intravitreal anti-VEGF injections: a systematic review

PURPOSE

To review the risk of systemic adverse events and all-cause mortality following same-day bilateral anti-VEGF injections.

METHODS

Twelve literature databases were searched for studies on same-session bilateral intravitreal anti-VEGF injections. Studies reporting on systemic adverse events and mortality were included. Data extraction was made independently by two authors and discussed afterwards until consensus was reached.

RESULTS

Seven studies were included with a total of 13,406 intravitreal anti-VEGF injections (6703 bilateral injections sessions) given to 689 patients. Across all studies, mean age of patients ranged from 55.7 to 82.5 years, and mean follow-up times ranged from 1.3 to 41 months. Six studies reported on systemic adverse events: Two cases of non-fatal cardiac adverse events were reported after 12,964 injections (6482 bilateral injection sessions) in 626 patients. Four studies reported on death: 12 deaths were recorded after 6233 bilateral injection sessions in a total population of 554 subjects.

CONCLUSIONS

We suggest that the risk of non-fatal systemic adverse events and death after same-session bilateral anti-VEGF injection is reasonably low, but larger studies with follow-ups of several years are needed to quantify the exact risk.

STUDY REGISTRATION

Prospectively registered in PROSPERO, registration ID: CRD42023428254, registration date: 20/05/2023.

Endophthalmitis following same-day bilateral anti-VEGF injections: a systematic review

PURPOSE

To review the risk of endophthalmitis in same-day bilateral anti-VEGF injections.

METHODS

We searched 12 literature databases for studies on the risk of endophthalmitis after same-day bilateral intravitreal anti-VEGF injections. Data extraction was made independently by two authors and discussed afterward until reaching consensus.

RESULTS

Seventeen studies were included with a total of 138,478 intravitreal anti-VEGF injections (69,239 bilateral injections sessions) given in at least 7579 patients. In total, 33 cases of endophthalmitis had occurred, and no cases were bilateral. The incidence of endophthalmitis ranged from 0 to 0.53% per intravitreal injection across studies.

CONCLUSIONS

We suggest that clinicians can consider same-day treatment of both eyes of patients in need of bilateral intravitreal anti-VEGF injection therapy, but larger studies are needed to quantify the exact risk of endophthalmitis.

Beyond bronchodilation: Illuminating the performance benefits of inhaled beta2 -agonists in sports

Given the prevalent use of inhaled beta2 -agonists in sports, there is an ongoing debate as to whether they enhance athletic performance. Over the last decades, inhaled beta2 -agonists have been claimed not to enhance performance with little consideration of dose or exercise modality. In contrast, orally administered beta2 -agonists are perceived as being performance enhancing, predominantly on muscle strength and sprint ability, but can also induce muscle hypertrophy and slow-to-fast fiber phenotypic switching. But because inhaled beta2 -agonists are more efficient to achieve high systemic concentrations than oral delivery relative to dose, it follows that the inhaled route has the potential to enhance performance too. The question is at which inhaled doses such effects occur. While supratherapeutic doses of inhaled beta2 -agonists enhance muscle strength and short intense exercise performance, effects at low therapeutic doses are less apparent. However, even high therapeutic inhaled doses of commonly used beta2 -agonists have been shown to induce muscle hypertrophy and to enhance sprint performance. This is concerning from an anti-doping perspective. In this paper, we raise awareness of the circumstances under which inhaled beta2 -agonists can constitute a performance-enhancing benefit.

Asthma and exercise-induced bronchoconstriction in athletes: Diagnosis, treatment, and anti-doping challenges

Athletes often experience lower airway dysfunction, such as asthma and exercise-induced bronchoconstriction (EIB), which affects more than half the athletes in some sports, not least in endurance sports. Symptoms include coughing, wheezing, and breathlessness, alongside airway narrowing, hyperresponsiveness, and inflammation. Early diagnosis and management are essential. Not only because untreated or poorly managed asthma and EIB potentially affects competition performance and training, but also because untreated airway inflammation can result in airway epithelial damage, remodeling, and fibrosis. Asthma and EIB do not hinder performance, as advancements in treatment strategies have made it possible for affected athletes to compete at the highest level. However, practitioners and athletes must ensure that the treatment complies with general guidelines and anti-doping regulations to prevent the risk of a doping sanction because of inadvertently exceeding specified dosing limits. In this review, we describe considerations and challenges in diagnosing and managing athletes with asthma and EIB. We also discuss challenges facing athletes with asthma and EIB, while also being subject to anti-doping regulations.

Acute Effects of Single Versus Combined Inhaled β2-Agonists Salbutamol and Formoterol on Time Trial Performance, Lung Function, Metabolic and Endocrine Variables

BACKGROUND

High prevalence rates of β2-agonist use among athletes in competitive sports makes it tempting to speculate that illegitimate use of β2-agonists boosts performance. However, data regarding the potential performance-enhancing effects of inhaled β2-agonists and its underlying molecular basis are scarce.

METHODS

In total, 24 competitive endurance athletes (12f/12m) participated in a clinical double-blinded balanced four-way block cross-over trial to investigate single versus combined effects of β2-agonists salbutamol (SAL) and formoterol (FOR), to evaluate the potential performance enhancement of SAL (1200 µg, Cyclocaps, Pb Pharma GmbH), FOR (36 µg, Sandoz, HEXAL AG) and SAL + FOR (1200 µg + 36 µg) compared to placebo (PLA, Gelatine capsules containing lactose monohydrate, Pharmacy of the University Hospital Ulm). Measurements included skeletal muscle gene and protein expression, endocrine regulation, urinary/serum β2-agonist concentrations, cardiac markers, cardiopulmonary and lung function testing and the 10-min time trial (TT) performance on a bicycle ergometer as outcome variables. Blood and urine samples were collected pre-, post-, 3 h post- and 24 h post-TT.

RESULTS

Mean power output during TT was not different between study arms. Treatment effects regarding lung function (p < 0.001), echocardiographic (left ventricular end-systolic volume p = 0.037; endocardial global longitudinal strain p < 0.001) and metabolic variables (e.g. NR4A2 and ATF3 pathway) were observed without any influence on performance. In female athletes, total serum β2-agonist concentrations for SAL and FOR were higher. Microarray muscle gene analysis showed a treatment effect for target genes in energy metabolism with strongest effect by SAL + FOR (NR4A2; p = 0.001). Of endocrine variables, follicle-stimulating hormone (3 h Post-Post-TT), luteinizing hormone (3 h Post-Pre-TT) and insulin (Post-Pre-TT) concentrations showed a treatment effect (all p < 0.05).

CONCLUSIONS

No endurance performance-enhancing effect for SAL, FOR or SAL + FOR within the permitted dosages compared to PLA was found despite an acute effect on lung and cardiac function as well as endocrine and metabolic variables in healthy participants. The impact of combined β2-agonists on performance and sex-specific thresholds on the molecular and cardiac level and their potential long-term performance enhancing or health effects have still to be determined.

TRIAL REGISTRATION

Registered at Eudra CT with the number: 2015-005598-19 (09.12.2015) and DRKS with number DRKS00010574 (16.11.2021, retrospectively registered).

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/).

High training volume is associated with increased prevalence of non-allergic asthma in competitive cross-country skiers

Background

Cross-country skiers have a high prevalence of asthma, but its phenotypes and association with success in competitions are not known.

Objective

To investigate, by means of a postal survey, the relative proportions of allergic and non-allergic asthma in competitive cross-country skiers compared with the general population, to study how performance level and training volume are related to asthma and its type and to assess the possible risk factors for allergic and non-allergic asthma in competitive skiers.

Methods

All Finnish cross-country skiers enrolled in the largest national competitions in winter 2019 (n=1282), and a random sample (n=1754) of the general population of the same age were sent a postal questionnaire. The response rate was 27.4% (n=351) for skiers and 19.5% (n=338) for the controls. International Ski Federation (FIS) ranking points measured the level of success in skiers. Asthma was defined as self-reported, physician-diagnosed asthma. Asthma was considered allergic if associated with doctor-diagnosed allergy, and exposure to allergens provoked asthma symptoms.

Results

The prevalence of asthma was higher in skiers than in the controls (25.9% vs 9.2%, p<0.001), and it was the highest (56.1%) in the most successful quartile of skiers. Asthma was more often non-allergic in skiers than in the controls (60.1% vs 38.7%, p=0.036). Being a skier came with a higher risk for non-allergic (OR 5.05, 95% CI 2.65 to 9.61) than allergic asthma (OR 1.92, 1.08–3.42). Using multivariable regression analysis, training volume was associated with non-allergic asthma, while age, family history of asthma and allergic rhinitis were associated with allergic asthma.

Conclusion

The prevalence of asthma is the highest in the most successful cross-country skiers. The asthma in skiers is mostly non-allergic compared with the general population of the same age. The most important risk factor for non-allergic asthma in skiers is high training volume.

The ELSA trial: single versus combinatory effects of non-prohibited beta-2 agonists on skeletal muscle metabolism, cardio-pulmonary function and endurance performance-study protocol for a randomized 4-way balanced cross-over trial

BACKGROUND

Asthma and/or airway hyper-responsiveness (AHR) are common in elite endurance athletes with a high prevalence rate of beta-2 adrenoreceptor (beta-2) agonists use. Nevertheless, there are data on dose-dependent ergogenic effects of beta-2 agonists suggesting increased muscle strength, endurance and neuromuscular performance. Therefore, most beta-2 agonists belong to the World Anti Doping Agency (WADA) list of prohibited substances and it is tempting to speculate that illegitimate use of beta-2 agonists might be a common practice to boost performance in competitive sports. It is currently unknown whether or not inhaled beta-2 agonists enhance performance by stimulatory effects in skeletal and cardiac muscle.

METHODS

The ELSA trial is a double-blinded, placebo-controlled, randomized, balanced, four-way cross-over study. Study participants (n=24, 12 ♀, 12 ♂) complete four study arms (i.e. periods with treatment A, placebo; B, salbutamol; C, formoterol; D, formoterol + salbutamol) in random order after an initial preliminary testing session. Participants inhale the study medication 20 min before the 10-min time trial (TT; exercise performance test), where participants cycle 10 min at the highest possible workload. Cardiac output is measured continuously. A skeletal muscle biopsy is collected 3 h after the TT. Study endpoints include measures of skeletal muscle expression of nuclear receptors, hormones and cytokine levels, urinary and plasma concentrations of salbutamol and formoterol, circulating cardiac markers, cardiopulmonary function and exercise performance (average power and peak power during the TT). Blood and urine are collected and respiratory testing is performed 24 h post TT. This clinical trial evaluates the potential performance-enhancing effects of non-prohibited, not medically indicated inhaled short- and long-acting beta-2 agonists on skeletal muscle gene expression, endocrine regulation, cardiac biomarkers, cardiopulmonary function and acute endurance exercise performance. These data will be used by WADA to adapt the annually published list of prohibited substances (WADA 2021) and will be published in scientific journals.

TRIAL REGISTRATION

The trial is registered at the European Clinical Trials Database (Eudra CT) with the number: 2015-005598-19 as well as at the German register for clinical studies (DRKS number 00010574 ).

An Abductive Inference Approach to Assess the Performance-Enhancing Effects of Drugs Included on the World Anti-Doping Agency Prohibited List

Some have questioned the evidence for performance-enhancing effects of several substances included on the World Anti-Doping Agency's Prohibited List due to the divergent or inconclusive findings in randomized controlled trials (RCTs). However, inductive statistical inference based on RCTs-only may result in biased conclusions because of the scarcity of studies, inter-study heterogeneity, too few outcome events, or insufficient power. An abductive inference approach, where the body of evidence is evaluated beyond considerations of statistical significance, may serve as a tool to assess the plausibility of performance-enhancing effects of substances by also considering observations and facts not solely obtained from RCTs. Herein, we explored the applicability of an abductive inference approach as a tool to assess the performance-enhancing effects of substances included on the Prohibited List. We applied an abductive inference approach to make inferences on debated issues pertaining to the ergogenic effects of recombinant human erythropoietin (rHuEPO), beta₂-agonists and anabolic androgenic steroids (AAS), and extended the approach to more controversial drug classes where RCTs are limited. We report that an abductive inference approach is a useful tool to assess the ergogenic effect of substances included on the Prohibited List-particularly for substances where inductive inference is inconclusive. Specifically, a systematic abductive inference approach can aid researchers in assessing the effects of doping substances, either by leading to suggestions of causal relationships or identifying the need for additional research.

Asthma medication in athletes: a qualitative investigation of adherence, avoidance and misuse in competitive sport

OBJECTIVES

The purpose of this qualitative study was to utilize the Capability, Opportunity, Motivation - Behavior model (COM-B) to: (1) evaluate athlete knowledge and understanding of current asthma-related anti-doping regulations, (2) explore the impact of environmental and societal influences on athletes with asthma, and (3) examine athlete perception of asthma medication use in competitive sport.Methods: Semi-structured interviews were conducted with ten competitive endurance athletes (five athletes with asthma and five without asthma). Interviews were guided by the COM-B model and transcripts were analyzed inductively and deductively using reflexive thematic analysis.Results: Mapping the experiences and perceptions of athletes against an established behavioral framework identified that: (1) athletes' possess limited knowledge and understanding of the World Anti-Doping Agency (WADA) Prohibited List and Therapeutic use exemption (TUE) policy with respect to asthma medication; (2) the use of sub-optimal diagnostic methods is commonplace and increases the risk of misdiagnosis and unnecessary inhaler therapy; (3) negative media portrayal of high-profile asthma-related doping allegations impacts public opinion and contributes to the perception of wrongdoing within the sporting community.Conclusion: The novel application of behavioral science highlights several factors that may contribute to asthma medication avoidance and promote misuse in competitive sport. The findings from this study provide a foundation for the development and implementation of targeted education programmes, and it is hoped that employing this approach will ultimately improve overall perceptions of asthma treatment in athletes, which is necessary to maintain respiratory health, optimize performance and protect the integrity of sport.

© 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.

Aerobic performance among healthy (non-asthmatic) adults using beta2-agonists: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To examine the effect of beta2-agonists on aerobic performance in healthy, non-asthmatic study participants.

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA

We searched four databases (PubMed, Embase, SPORTDiscus and Web of Science) for randomised controlled trials published until December 2019. Studies examining the effect of beta2-agonists on maximal physical performance lasting longer than 1 min were included in the meta-analysis. Data are presented as standardised difference in mean (SDM) with 95% CI.

RESULTS

The present meta-analysis includes 47 studies. The studies comprise 607 participants in cross-over trials, including 99 participants in three-way cross-over trials and 27 participants in a four-way cross-over trial. Seventy-three participants were included in parallel trials. Beta2-agonists did not affect aerobic performance compared with placebo (SDM 0.051, 95% CI -0.020 to 0.122). The SDM for the included studies was not heterogeneous (I²=0%, p=0.893), and the effect was not related to type of beta2-agonist, dose, administration route, duration of treatment or performance level of participants. Beta2-agonists had no effect on time trial performance, time to exhaustion or maximal oxygen consumption (p<0.218).

CONCLUSION/IMPLICATION

The present study shows that beta2-agonists do not affect aerobic performance in non-asthmatic subjects regardless of type, dose, administration route, duration of treatment or performance level of participants. The results of the present study should be of interest to WADA and to anyone who is interested in equal opportunities in competitive sports.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018109223.

Can β2-agonists have an ergogenic effect on strength, sprint or power performance? Systematic review and meta-analysis of RCTs

OBJECTIVES

We aimed to examine the effect of β2-agonists on anaerobic performance in healthy non-asthmatic subjects.

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA

We searched four databases (PubMed, Embase, SPORTDiscus and Web of Science) for randomised controlled trials, published until December 2019, examining the effect of β2-agonists on maximal physical performance lasting 1 min or shorter. Data are presented as standardised difference in mean (SDM) with 95% confidence intervals (95% CI).

RESULTS

34 studies were included in the present meta-analysis. The studies include 44 different randomised and placebo-controlled comparisons with β2-agonists comprising 323 participants in crossover trials, and 149 participants in parallel trials. In the overall analyses, β2-agonists improved anaerobic performance by 5% (SDM 0.29, 95% CI 0.16 to 0.42), but the effect was related to dose and administration route. In a stratified analysis, the SDM was 0.14 (95% CI 0.00 to 0.28) for approved β2-agonists and 0.46 (95% CI 0.24 to 0.68) for prohibited β2-agonists, respectively. Furthermore, SDM was 0.16 (95% CI 0.02 to 0.30) for inhaled administration and 0.51 (95% CI 0.25 to 0.77) for oral administration, respectively, and 0.20 (95% CI 0.07 to 0.33) for acute treatment and 0.50 (95% CI 0.20 to 0.80) for treatment for multiple weeks. Analyses stratified for the type of performance showed that strength (0.35, 95% CI 0.15 to 0.55) and sprint (0.17, 95% CI 0.06 to 0.29) performance were improved by β2-agonists.

CONCLUSION/IMPLICATION

Our study shows that non-asthmatic subjects can improve sprint and strength performance by using β2-agonists. It is uncertain, however, whether World Anti-Doping Agency (WADA)-approved doses of β2-agonists improve performance. Our results support that the use of β2-agonists should be controlled and restricted to athletes with documented asthma.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018109223.

Prevalence of therapeutic use exemptions at the Olympic Games and association with medals: an analysis of data from 2010 to 2018

Objectives

The percentage of athletes with Therapeutic Use Exemptions (TUEs) competing in elite sport and the association with winning medals has been a matter of speculation in the absence of validated competitor numbers. We used International Olympic Committee (IOC) and World Anti-Doping Agency (WADA) data to identify athletes competing with TUEs at five Olympic Games (Games) and a possible association between having a TUE and winning an Olympic medal.

Methods

We used the IOC’s competition results and WADA’s TUE database to identify the number of TUEs for athlete competitions (ACs, defined as one athlete competing in one event) and any associations with medals among athletes competing in individual competitions. We calculated risk ratios (RR) for the probability of winning a medal among athletes with a TUE compared with that of athletes without a TUE. We also reported adjusted RR (RR_adj) controlling for country resources, which is a potential confounder.

Results

During the Games from 2010 to 2018, there were 20 139 ACs and 2062 medals awarded. Athletes competed with a TUE in 0.9% (181/20 139) of ACs. There were 21/2062 medals won by athletes with a TUE. The RR for winning a medal with a TUE was 1.13 (95% CI: 0.73 to 1.65; p=0.54), and the RR_adj was 1.07 (95% CI: 0.69 to 1.56; p=0.73).

Conclusion

The number of athletes competing with valid TUEs at Games is <1%. Our results suggested that there is no meaningful association between being granted a TUE and the likelihood of winning a medal.

The Systemic Safety of Ranibizumab in Patients 85 Years and Older with Neovascular Age-Related Macular Degeneration

OBJECTIVE

Ranibizumab safety is well established for treatment of neovascular age-related macular degeneration (nAMD), but less is known about the risk of systemic serious adverse events (SAEs), specifically among patients with heightened baseline risk due to age (≥85 years). This analysis examines whether patients ≥85 years of age versus those <85 years experience an increased risk of key systemic SAEs during intravitreal ranibizumab treatment for nAMD.

DESIGN

Retrospective, pooled analysis of safety data from 5 phase III/IIIb multicenter randomized clinical trials in patients with nAMD: ANCHOR, MARINA, PIER, SAILOR, and HARBOR.

PARTICIPANTS

Patients with nAMD receiving ranibizumab (n = 4347) or control (sham/verteporfin photodynamic therapy, n = 441) treatment included in the safety-evaluable set of the 5 trials.

METHODS

The incidence of nonocular SAEs was analyzed stratified by age (<85 years [n = 3795] vs ≥85 years [n = 993]), treatment (control, ranibizumab 0.3 mg, ranibizumab 0.5 mg, ranibizumab 2.0 mg), and injection frequency (monthly, as needed [PRN]).

MAIN OUTCOME MEASURES

Incidence of key systemic SAEs, defined as total nonocular SAEs, deaths, cardiovascular events, cerebrovascular (CBV) events, and Antiplatelet Trialists' Collaboration events.

RESULTS

The MARINA and ANCHOR trials had greater rates of key SAEs for patients ≥85 years versus those <85 years. Ranibizumab exposure did not increase the risk of most SAEs in elderly patients; for CBV events and death, the effect of ranibizumab versus control treatment for age ≥85 years was not interpretable due to small number of events (CBV: n = 2, 2, 5 for control, ranibizumab 0.3 mg, and ranibizumab 0.5 mg, respectively; death: n = 2, 4, 5, respectively). Across all 5 trials, an increased risk was found for age ≥85 years versus <85 years for the marketed dose of ranibizumab 0.5 mg. In the HARBOR trial, increased rates of key SAEs (excluding total nonocular SAEs) for age ≥85 years versus <85 years were observed with monthly dosing but not with PRN dosing; event rates were similar for 2.0 mg versus 0.5 mg.

CONCLUSIONS

Consistent with general trends, the risk of key systemic SAEs was associated with age ≥85 years versus <85 years, but not with ranibizumab drug exposure. The difference between monthly versus PRN was inconclusive. There was no evidence of a dose effect. Interpretation of this retrospective analysis is limited because it was not prospectively powered for statistically definitive conclusions.

Beta2-Agonist Doping Control and Optical Isomer Challenges

The World Anti-Doping Agency (WADA) currently allows therapeutic use of the beta2-agonists salbutamol, formoterol and salmeterol when delivered via inhalation despite some evidence suggesting these anti-asthma drugs may be performance enhancing. Beta2-agonists are usually administered as 50:50 racemic mixtures of two enantiomers (non-superimposable mirror images), one of which demonstrates significant beta2-adrenoceptor-mediated bronchodilation while the other appears to have little or no pharmacological activity. For salbutamol and formoterol, urine thresholds have been adopted to limit supratherapeutic dosing and to discriminate between inhaled (permitted) and oral (prohibited) use. However, chiral switches have led to the availability of enantiopure (active enantiomer only) preparations of salbutamol and formoterol, which effectively doubles their urine thresholds and provides a means for athletes to take supratherapeutic doses for doping purposes. Given the availability of these enantiopure beta2-agonists, the analysis of these drugs using enantioselective assays should now become routine. For salmeterol, there is currently only a therapeutic dose threshold and adoption of a urinary threshold should be a high priority for doping control.

Asthma pressurised metered dose inhaler performance: propellant effect studies in delivery systems

BACKGROUND

Current pressurised metered dose asthma inhaler (pMDI) propellants are not inert pharmacologically as were previous chlorofluorocarbons, have smooth muscle relaxant' partial pressure effects in the lungs and inhaled hydrofluoroalkane 134a (norflurane) has anaesthetic effects. Volumes of propellant gas per actuation have never been measured.

METHODS

In-vitro studies measured gas volumes produced by pMDIs on air oxygen (O2) levels in valved holding chambers (VHC) and the falls in O2% following actuation into lung ventilator delivery devices.

RESULTS

Volumes of propellant gas hydrofluoroalkane (HFA) 134a and 227ea and redundant chlorofluorocarbons (CFC) varied from 7 ml per actuation from a small salbutamol HFA inhaler to 16 ml from the larger. Similar-sized CFC pMDI volumes were 15.6 and 20.4 ml. Each HFA salbutamol inhaler has 220 full volume discharges; total volume of gas from a small 134a pMDI was 1640 ml, and large 3885 ml. Sensing the presence of liquid propellant by shaking was felt at the 220th discharge in both large and small inhalers. Because of a partial pressure effect, VHC O2% in air was reduced to 11% in the smallest 127 ml volume VHC following 10 actuations of a large 134a salbutamol inhaler. The four ventilator delivery devices studied lowered 100% oxygen levels to a range of 93 to 81% after five actuations, depending on the device and type of pMDI used.

CONCLUSION

Pressurised inhaler propellants require further study to assess smooth muscle relaxing properties.

Pharmacokinetics of Oral and Inhaled Terbutaline after Exercise in Trained Men

Aim: The aim of the study was to investigate pharmacokinetics of terbutaline after oral and inhaled administration in healthy trained male subjects in relation to doping control.

Methods: Twelve healthy well-trained young men (27 ±2 years; mean ± SE) underwent two pharmacokinetic trials that compared 10 mg oral terbutaline with 4 mg inhaled dry powder terbutaline. During each trial, subjects performed 90 min of bike ergometer exercise at 65% of maximal oxygen consumption. Blood (0–4 h) and urine (0–24 h) samples were collected before and after administration of terbutaline. Samples were analyzed for concentrations of terbutaline by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS).

Results: Pharmacokinetics differed between the two routes of administration. Serum C_max and area under the serum concentration-time curve (AUC) were lower after oral administration compared to inhalation (C_max: 4.2 ± 0.3 vs. 8.5 ± 0.7 ng/ml, P ≤ 0.001; AUC: 422 ± 22 vs. 1308 ± 119 ng/ml × min). Urine concentrations (sum of the free drug and the glucuronide) were lower after oral administration compared to inhalation 2 h (1100 ± 204 vs. 61 ± 10 ng/ml, P ≤ 0.05) and 4 h (734 ± 110 vs. 340 ± 48 ng/ml, P ≤ 0.001) following administration, whereas concentrations were higher for oral administration than inhalation 12 h following administration (190 ± 41 vs. 399 ± 108 ng/ml, P ≤ 0.05). Urine excretion rate was lower after oral administration than inhalation the first 2 h following administration (P ≤ 0.001). Systemic bioavailability ratio between the two routes of administration was 3.8:1 (inhaled: oral; P ≤ 0.001).

Conclusion: Given the higher systemic bioavailability of inhaled terbutaline compared to oral, our results indicate that it is difficult to differentiate allowed inhaled use of terbutaline from prohibited oral ingestion based on urine concentrations in doping control analysis. However given the potential performance enhancing effect of high dose terbutaline, it is essential to establish a limit on the WADA doping list.

The impact of exercise-induced bronchoconstriction on athletic performance: a systematic review

BACKGROUND

Exercise-induced bronchoconstriction (EIB) describes the phenomenon of transient airway narrowing in association with physical activity. Although it may seem likely that EIB would have a detrimental impact on athletic performance, this has yet to be established.

OBJECTIVES

The aim of this review is to provide a systematic appraisal of the current status of knowledge regarding EIB and exercise performance and to highlight potential mechanisms by which performance may be compromised by EIB.

DATA SOURCES AND STUDY SELECTION

PubMed/Medline and EBSCO databases were searched up to May 2014 using the search parameter: [('exercise' OR 'athlete') AND ('asthma' OR 'bronchoconstriction' OR 'hypersensitivity') AND 'performance']. This search string returned 243 citations. After systematically reviewing all of the abstracts, 101 duplicate papers were removed, with 132 papers excluded for not including an exercise performance outcome measure.

RESULTS

The remaining ten studies that met the initial criteria were included in this review; six evaluated the performance of physically active individuals with asthma and/or EIB while four assessed the effects of medication on performance in a comparable population.

CONCLUSION

The evidence concludes that whilst it is reasonable to suspect that EIB does impact athletic performance, there is currently insufficient evidence to provide a definitive answer.

Effects of acute and 2-week administration of oral salbutamol on exercise performance and muscle strength in athletes

Our objective was to investigate effects of acute and 2-week administration of oral salbutamol on repeated sprint ability, exercise performance, and muscle strength in elite endurance athletes. Twenty male elite athletes [VO2max: 69.4 ± 1.8 (Mean ± SE) mL/min/kg], aged 25.9 ± 1.4 years, were included in a randomized, double-blinded and placebo-controlled parallel study. At baseline, after acute administration, and again after 2-week administration of the study drugs (8 mg salbutamol or placebo), subjects' maximal voluntary contraction (MVC) of m. quadriceps and isometric endurance of m. deltoideus were measured, followed by three repeated Wingate tests. Exercise performance at 110% of VO2max was determined on a bike ergometer. Acute administration of salbutamol increased peak power during first Wingate test by 4.1 ± 1.7% (P < 0.05). Two-week administration of salbutamol increased (P < 0.05) peak power during first and second Wingate test by 6.4 ± 2.0 and 4.2 ± 1.0%. Neither acute nor 2-week administration of salbutamol had any effect on MVC, exercise performance at 110% of VO2max or on isometric endurance. No differences were observed in the placebo group. In conclusion, salbutamol benefits athletes' sprint ability. Thus, the present study supports the restriction of oral salbutamol in competitive sports.

Canadian Academy of Sport and Exercise Medicine position statement: athletes at high altitude

Many sports incorporate training at altitude as a key component of their athlete training plan. Furthermore, many sports are required to compete at high altitude venues. Exercise at high altitude provides unique challenges to the athlete and to the sport medicine clinician working with these athletes. These challenges include altitude illness, alterations in training intensity and performance, nutritional and hydration difficulties, and challenges related to the austerity of the environment. Furthermore, many of the strategies that are typically utilized by visitors to altitude may have implications from an anti-doping point of view.This position statement was commissioned and approved by the Canadian Academy of Sport and Exercise Medicine. The purpose of this statement was to provide an evidence-based, best practices summary to assist clinicians with the preparation and management of athletes and individuals travelling to altitude for both competition and training.

Combined inhalation of beta2 -agonists improves swim ergometer sprint performance but not high-intensity swim performance

There is a high prevalence of asthma and airway hyperresponsiveness (AHR) in elite athletes, which leads to a major use of beta2 -agonists. In a randomized double-blinded crossover study, we investigated the effects of combined inhalation of beta2 -agonists (salbutamol, formoterol, and salmeterol), in permitted doses within the World Anti-Doping Agency 2013 prohibited list, in elite swimmers with (AHR, n = 13) or without (non-AHR, n = 17) AHR. Maximal voluntary isometric contraction of m. quadriceps (MVC), sprint performance on a swim ergometer and performance in an exhaustive swim test at 110% of VO2max were determined. Venous plasma interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured post-exercise. No improvement was observed in the exhaustive swim test, but swim ergometer sprint time was improved (P < 0.05) in both groups from 57 ± 1.7 to 56 ± 1.8 s in AHR and 58.3 ± 1 to 57.4 ± 1 s in non-AHR. MVC and post-exercise plasma IL-6 increased (P < 0.05) with beta2 -agonists in both groups, whereas IL-8 only increased in AHR. In summary, inhalation of beta2 -agonists, in permitted doses, did not improve swim performance in elite swimmers. However, swim ergometer sprint performance and MVC were increased, which should be considered when making future anti-doping regulations.

Impact of changes in anti-doping regulations (WADA Guidelines) on asthma care in athletes

OBJECTIVE

To investigate how changes to the World Anti-Doping Agency (WADA) guidelines on asthma medication requests have impacted the management of asthmatic athletes in Portugal.

DESIGN

Retrospective analysis of asthma medication requests submitted in 2008 to 2010.

SETTING

Portuguese Anti-Doping Authority database.

PARTICIPANTS

Athletes requesting the use of inhaled corticosteroids and/or β2-agonists.

INDEPENDENT VARIABLES

Demographic, therapeutic, and diagnostic test data.

MAIN OUTCOME MEASURES

Yearly changes in number of asthma medication requests and diagnostic procedures.

RESULTS

We analyzed 326 requests: 173 abbreviated Therapeutic Use Exemptions (TUEs) in 2008 (objective tests not required), 9 Declaration of Use (DoU) and 76 TUEs in 2009, and 39 DoU and 29 TUEs in 2010. Spirometry was performed in 87% and 37% of athletes in 2009 and 2010, respectively; the corresponding figures for bronchoprovocation were 59% and 16%, almost all positive in both years.

CONCLUSIONS

Applications for inhaler use have decreased by approximately half since objective asthma testing became mandatory. Our findings show that WADA guidelines have an impact on asthmatic athletes care: In 2009 a more rigorous screening was possible, leading to withdrawal of unnecessary medication. Constant changes, however, jeopardize this achievement and nowadays introduce safety issues stemming from the unsupervised use of inhaled β2-agonists.

Prioritising health in anti-doping: what Australians think

OBJECTIVES

There is debate concerning whether the guiding paradigm for anti-doping policy should be the current legalistic approach or a "harm minimisation" approach prioritising athlete health. This study sought to determine whether a representative sample of Australians prioritises health above other concerns using the World Anti-Doping Code's Spirit of Sport statement which lists the 11 attributes that define the moral basis for anti-doping.

DESIGN

A Best-Worst Scaling (BWS) Balanced Incomplete Block Design experiment using 11 choice sets of five Spirit attributes from the set of 11, with the attributes within each choice set in a random order.

METHODS

A representative sample of n=168 Australians responded to an on-line survey. The BWS scores defined the relative ranking of each attribute to define an aggregate model and demographically defined models (gender, education, sports participation and sports following).

RESULTS

Health was ranked as 7/11 in the aggregate model. Only those who did not follow sport prioritised health (2/11), with other demographic models failing to show a meaningful departure from the aggregate model.

CONCLUSIONS

Australians ranked health below other attributes in the Spirit of Sport, appearing to prioritise "rule following" consistent with the legalistic approach. This challenges the harm minimisation approach to managing the role of drugs in sport and suggests that rule-following and legalistic approaches to drug use should take precedence over health messages.