Abstract

Background: Exercise induced bronchoconstriction (EIB) is common in elite athletes. Eucapnic voluntary hyperventilation (EVH) is a laboratory test recommended for the identification of EIB in athletes, secondary to a field exercise challenge. Montelukast attenuates EIB, but its protective effect against airway narrowing from EVH has not been investigated.

Objective: To examine the effectiveness of montelukast after exercise and after EVH.

Methods: A randomised, placebo controlled, double blind, crossover study was performed with 11 physically active EIB positive subjects (eight men, three women; mean (SD) age 22.8 (6.8) years). Six hours before each of the following challenges 10 mg montelukast or placebo was ingested: (a) a six minute, cold air (−3°C) maximal effort work accumulation cycle ergometer exercise; (b) EVH, breathing 5% CO₂ compressed air at 85% maximal voluntary ventilation for six minutes. Spirometry was performed before and 5, 10, and 15 minutes after the challenge. At least 48 hours was observed between challenges.

Results: No differences in forced expiratory volume in one second (FEV₁) were found after the two challenges. Exercise and EVH resulted in falls in FEV₁ of 22.4 (18.0) and 25.6 (16.8) respectively. Falls in FEV₁ after montelukast were less than after placebo (10.6 (10.6) and 14.3 (11.3) after exercise and EVH respectively; p<0.05). Montelukast provided protection against bronchoconstriction (59% and 53%; p<0.05) for eight exercising subjects and 10 EVH subjects; no protection was afforded for three exercising and one EVH challenged subject.

Conclusions: Both exercise and EVH were potent stimuli of airway narrowing. A single dose of montelukast provided reasonable protection in attenuating bronchoconstriction from either exercise or EVH. The similar protection by montelukast suggests that EVH is a suitable laboratory surrogate for EIB evaluation.