Self-reported symptoms and bronchial hyperresponsiveness in elite cross-country skiers

Introduction: Respiratory symptoms in relationship to exercise, bronchial hyperresponsiveness (BHR), and exercise-induced asthma (EIA) are very common in elite winter athletes. Symptom-based screening for BHR would facilitate selection of athletes with possible EIA. Objectives: The aim of the present study was to evaluate the diagnostic accuracy of self-reported symptoms as predictors of BHR in an unselected population of adult elite cross-country skiers. Methods: Forty-six Swedish adult skiers competing at national or international level were included. They had a mean (SD) training volume in the past 12 months of 593 (122) hours. Twenty-four subjects had previous physician-diagnosed asthma. The European Community Respiratory Health Survey questionnaire was used to evaluate the presence of respiratory symptoms. BHR was defined as bronchoconstriction to either eucapnic voluntary hyperventilation, dry powder mannitol or methacholine provocation. Results: The "classical" EIA symptom of shortness of breath post-exercise was reported by 17% of all skiers. Eight subjects (17%) had BHR. None of the self-reported respiratory symptoms had high positive predictive values. However, symptoms caused by grass or pollen had high negative predictive values. Discussion: EIA in elite winter athletes cannot accurately be based only on self-reported symptoms but requires verification with objective testing of BHR. Bronchoprovocation of elite winter athletes reporting respiratory symptoms in rest or because of exercise will probably reveal a high proportion of athletes without BHR. Clinical trial: EUDRA-CT number 2006-005822-21. (C) 2010 Elsevier Ltd. All rights reserved.