Relationship between dysfunctional breathing and exercise-induced bronchoconstriction in athletic populations

Introduction: Dysfunctional breathing (DB) may mimic and/or coexist with exercise-induced bronchoconstriction (EIB) and tools to aid diagnosis precision are needed. Aims and objectives: The aim of this study was to evaluate the relationship between the score of a commonly used questionnaire to detect DB, namely the Nijmegen questionnaire (NQ) and objective evidence of EIB, from indirect bronchoprovocation testing. Methods: One hundred and four athletes (Mean +/- SD age: 23.1±4.4 yrs.; n=79 (76%) males; n=62 (59.6%) elite athletes); underwent an eucapnic voluntary hyperpnoea (EVH) challenge and completed the NQ. A cut-off value of ?10% in FEV1 fall from baseline in EVH post challenge and a score of ? 23 in the NQ were considered positive results. Results: Fifty-two (50%) participants had a positive EVH challenge and 17 (16.4%) had a positive NQ score. We found no relationship between mean NQ scores and the maximal fall in FEV1 post-EVH challenge (r= -0.09; p=0.37). The sensitivity, specificity, positive predicted value (PPV) and negative predicted value (NPV) of a positive NQ score predicting EIB were 15.38%, 82.69%, 47.06% and 49.43%, respectively. Conclusions: We found a poor relationship between NQ score and the outcome of the EVH challenge. Dysfunctional breathing may be best assessed using different objective measures than those used for diagnosis of obstructive airway disease