Airway Response to Methacholine following Eucapnic Voluntary Hyperpnea in Athletes

AimTo evaluate the changes in airway responsiveness to methacholine inhalation test (MIT) when performed after an eucapnic voluntary hyperpnea challenge (EVH) in athletes.MethodsTwo MIT preceded (visit 1) or not (visit 2) by an EVH, were performed in 28 athletes and 24 non-athletes. Twelve athletes and 13 non-athletes had airway hyperresponsiveness (AHR) to methacholine, and 11 athletes and 11 non-athletes had AHR to EVH (EVH+).ResultsThe MIT PC20 post-EVH was significantly lower compared to baseline MIT PC20 by 1.3±0.7 doubling-concentrations in EVH+ athletes only (p20 post-EVH and EVH+/EVH- status and athlete/nonathlete status was found (Adjusted R2=0.26 and pConclusionThe responsiveness to methacholine was increased by a previous indirect challenge in EVH+ athletes only. The mechanisms for such increase remain to be determined. MIT and EVH should ideally be performed on separate occasions as there is a small but possible risk to obtain a false-positive response to methacholine when performed immediately after the EVH.Trial RegistrationClinicalTrials.gov NCT00686491