Impact of Ethnicity, Gender, and Dehydration on the Urinary Excretion of Inhaled Salbutamol With Respect to Doping Control

OBJECTIVE: To examine the impact of dehydration, ethnicity, and gender on urinary concentrations of salbutamol in relation to the threshold stipulated by the World Anti-Doping Agency (WADA). DESIGN: Repeated measures open-label. PARTICIPANTS: Eighteen male and 14 female athletes (9 white males, 9 white females, 2 Afro-Caribbean males, 2 Afro-Caribbean females, 6 Asian [Indian subcontinent] males, and 4 Asian females) were recruited. All participants were nonasthmatic. INTERVENTIONS: After inhalation of 800 μg or 1600 μg of salbutamol, athletes exercised in a hot controlled environment (35°C, 40% relative humidity) at a self-selected pace until a target weight loss (2% or 5%) was achieved. MAIN OUTCOME MEASURES: Urine concentration of free salbutamol. RESULTS: After inhalation of 1600 μg salbutamol, 20 participants presented with a urine salbutamol concentrations above the current WADA limit (1000 ng/mL) and decision limit (1200 ng/mL) resulting in an adverse analytical finding. There were no differences according to gender or ethnic origin. CONCLUSIONS: Dehydration equivalent to a body mass loss greater than 2% concomitant to the acute inhalation of 1600 μg of salbutamol may result in a urine concentration above the current WADA limit and decision limit leading to a positive test finding independent of gender or ethnic origin. CLINICAL RELEVANCE: Asthmatic athletes using salbutamol should receive clear dosing advise and education to minimize the risk of inhaling doses of salbutamol that may produce urine concentrations of salbutamol above 1200 ng/mL.