Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge

Purpose: The purpose of this study was to compare a laboratory based exerci se challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function test (PFT) exercise-induced asthma (EIA) screening of elite athlet es. Methods: Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA (FBC screened) served as subjects. Twenty-three gender an d sport matched Controls (nonasthmatics) were randomly selected to establis h PFT reference values for normal elite athletes. Before FBC, athletes comp leted a medical history questionnaire for EIA symptoms. FBC evaluations con sisted of baseline spirometry, actual or simulated competition, and 5, 10, and 15 min postexercise spirometry. PFT positive athletes were evaluated in the laboratory using an exercise challenge simulating race intensity (ambi ent conditions: 21 degrees C, 60% relative humidity). PFT procedures were i dentical to FBC. Results: 91%, of PFT positive and 48% of PFT normal athlet es reported at least one symptom of EIA, with postrace cough most frequent. Baseline spirometry was the same for PFT positives and normal controls. Lo wer limit reference range (MN - 2 SD) of FEV1 for controls suggests that po stexercise decrements of greater than similar to-7% indicate abnormal airwa y response in this population. Exercise time duration did not effect bronch ial reactivity; 78% of FBC PFT positives; were PFT normal post-LBC. Conclus ion: Self-reported symptoms by elite athletes are not reliable in identifyi ng EIA. Reference range criterion for FEV1 decrement in the elite athlete p ostexercise contrasts current recommended guidelines. Moreover, a large num ber of false negatives may occur in this population if EIA screening is per formed with inadequate exercise and environmental stress.