Airway Inflammation and Epithelial Damage in Elite Swimmers and Skiers

M ANY athletes in endurance sports develop exerciseinduced asthma. A mixed neutrophilic/eosinophilic airway inflammation has been reported in swimmers and cross-country skiers, but its association with airway hyperresponsiveness (AHR) is unknown. This study evaluated patterns of inflammation and epithelial damage associated with "swimmers' asthma" and "skiers' asthma." The study included 64 high-level competitive swimmers and cold-air athletes (cross-country skiers, speed skaters, and biathletes). The athletes were studied during a period without recent training; patients with mild asthma and healthy controls were studied for comparison. All groups underwent allergy skin prick testing, methacholine challenge, and induced sputum analysis. Airway hyperreactivity was found in 69% of swimmers and 28% of cold-air athletes. On sputum analysis, neutrophil count was correlated with training hours in both groups of athletes. Swimmers had higher eosinophil counts than controls, but lower eosinophil counts than patients with mild asthma. Swimmers were the only group in which eosinophil count was correlated with AHR. Swimmers also had a higher bronchial epithelial cell count than controls or asthma patients, but epithelial damage was not correlated with AHR. Sputum eosinophil count was no higher in cold-air athletes than in healthy controls. In elite swimmers and cold-air athletes, evidence of airway inflammation is associated with AHR. Most of these high-level athletes--especially swimmers--have epithelial desquamation, which is not seen in patients with mild asthma. This bronchial epithelial damage, combined with training in cold air or chlorinated pools, could play a role in the development of airway remodeling and AHR.