Asthma, Airway Inflammation, and Epithelial Damage in Swimmers and Cold-air Athletes

¹ Unité de Recherche en Pneumologie, Centre de Recherche, Hôpital Laval, Université Laval, Québec, Canada

^* To whom correspondence should be addressed. E-mail: lpboulet{at}med.ulaval.ca.

	Abstract

Endurance athletes show an increased prevalence of airway hyperresponsiveness. The aim of this study was to evaluate the long-term effects of training on airway responsiveness, inflammation and epithelial damage in swimmers and cold-air athletes.

Sixty-four elite athletes (32 swimmers and 32 cold-air athletes), 32 mild asthmatic subjects and 32 healthy controls had allergy skin prick testing, methacholine challenge and induced sputum analysis.

Sixty-nine percent of swimmers and 28% of cold-air athletes had airway hyperresponsiveness. Sputum neutrophil count correlated with the number of training hours per week in both swimmers and cold-air athletes (r=0.58 and 0.52 respectively). Eosinophil counts were higher in swimmers than in healthy subjects, although lower than in asthmatic subjects, and correlated with airway hyperresponsiveness in swimmers only (r=0.64). Eosinophil count in cold-air athlete was similar to healthy subjects. Bronchial epithelial cell count was not correlated with airway hyperresponsiveness but was significantly increased in swimmers, compared with healthy and asthmatic controls.

In conclusion, we observed significant airway inflammation only in competitive athletes with airway hyperresponsiveness. The majority of elite athletes showed however evidences of bronchial epithelial damage that could possibly contribute to the development of airway hyperresponsiveness.