The enigma of inhaled salbutamol and sport: unresolved after 45 years

Asthma in elite athletes - do they have Type 2 or non-Type 2 disease? A new insight on the endotypes among elite athletes

Asthma and exercise-induced bronchoconstriction are highly prevalent in elite athletes compared with the general population. Some athletes have classic asthma with allergic sensitization; however, it seems that a proportion of athletes develop asthma as a result of several years of intensive training. It leads us to believe that asthma in athletes consists of at least two distinct endotypes - classic early-onset, Type 2 mediated asthma, and asthma with later onset caused by exercise which might be classified as non-Type 2 asthma. The purpose of this review is to evaluate the current literature on asthma in athletes focusing on inflammation and examine if asthma in athletes could be characterized as either Type 2- or non-Type 2 asthma.

Reference Values of Forced Vital Capacity and Expiratory Flow in High-Level Cyclists

Several studies have demonstrated that spirometric theoretical values may not be applicable to the high-level sports population. No reference values exist for high-level professional cyclists. We aimed to establish predictive spirometric values by reference equations. One hundred and forty-five French Caucasian high-level professional cyclists, aged 18–38, performed basic anthropometric assessment and spirometry during the medical evaluation at the beginning of the sport season. Measured values were compared with theoretical values. Predictive equations were established from anthropometric parameters to explain variations of spirometric parameters. High-level cyclists had significantly higher spirometric values than the theoretical values established from a general population, except for forced expiratory volume in one second (FEV₁), forced vital capacity (FVC) and forced expiratory flow (FEF) at 25% of FVC. Only FVC and FEV₁ were well predicted from body height. The FVC variation of 43.5% is explained by body height and weight. The FEV₁ variation of 25.8% is explained only by body height. High-level cycling is associated with important respiratory adaptations depending on the body height and the sport specificity: intensive and prolonged endurance training. These findings are interesting for clinical individual application to diagnose obstructive disease and test reversibility with bronchodilator drugs.

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.

Does the urinary concentration of an inhaled beta 2 agonist always reflect the inhaled dose and method of administration?

The urinary threshold of 1000 ng/mL for salbutamol was established by the International Olympic Committee (IOC) in 2001 following a study that was not undertaken for that purpose. At least 25 athletes have exceeded this concentration and some after inhaling no more than the permitted daily maximum dose of 1600 μg. However, there is concern that some providing expert evidence and tribunal members hearing such cases are unaware of the occasional unpredictability of the pharmacokinetics of beta‐2 agonists. The World Anti‐Doping Agency's (WADA's) change from 1 March 2018 to allow correction of urinary specific gravity (SG) down to 1.020 for prohibited substances with a urinary threshold is a major advance and will assist in some instances. However, future cases are anticipated to occur when athletes unexpectedly exceed the urinary threshold for salbutamol after inhaling no more than the allowable dose and within WADA's stated time frame. They will then be required to appear before doping tribunals. The rapidity by which salbutamol is inhaled can influence the resultant urinary concentration and is yet to be addressed adequately in WADA's 2019 Prohibited List. The list's recommended pharmacokinetic study fails to replicate the circumstances that prevailed when the athlete was competing and the adverse analytical finding (AAF) occurred. Tribunals, and experts who advise them, need to be cognizant that the urinary concentration of salbutamol does not invariably reflect the inhaled dose and that a high urinary salbutamol concentration is not always ipso facto evidence of super‐dosing with inhaled salbutamol.