Determinants of response to eucapneic hyperventilation with cold air in a population-based study.

A population-based, epidemiologic investigation conducted in children, adolescents, and young adults analyzed the response to eucapneic hyperventilation with cold air as a continuous variable to better define factors that influence the expression of bronchial responsiveness. Among respiratory illness/symptom variables, only the report of asthma or persistent wheeze in the previous year and the report of a respiratory illness that led to activity restriction were significantly associated with response to cold air. Furthermore, a low, prechallenge FEF/FVC ratio was a significant predictor of response, especially among those subjects who reported a respiratory illness that led to activity restriction. This relationship was not observed for a low prechallenge FEF.