The relation of adult bronchial responsiveness to serious childhood respiratory illness in the ECRHS

Background: Respiratory symptoms in adulthood have been found to be associated with childhood respiratory infection, but few studies have analyzed adult bronchial responsiveness (BHR) with adequate adjustment for known risk factors. Objective: To estimate the relation of BHR with serious childhood respiratory infections in a large population study. Methods: The European Community Respiratory Health Survey (ECRHS) was a cross-sectional population-based survey in 34 centers. Data on serious respiratory infections before the age of 5 years and possible confounders were obtained from a questionnaire administered in the clinic. Blood samples were taken for measurement of total immunoglobulin E (IgE) and specific IgE to four common allergens, and spirometry and bronchial challenge with methacholine were performed. A continuous measure of BHR was analyzed by multiple regression, in 11,282 participants, in relation to serious respiratory infection and other potential risk factors, adjusted for center and major determinants of adult BHR. Results: Those reporting a serious childhood respiratory infection had greater BHR, by an amount corresponding to approximately 0.23 doubling doses (95% confidence interval 0.02-0.44) of the amount of methacholine causing a 20% fall (PD₂₀) in forced expiratory volume in 1 s (FEV₁). All childhood factors explained less than 0.3% of variation in BHR in addition to over 20% by factors measured in adulthood. The relation of BHR to BMI was confined to smokers. Conclusions: We found an effect of serious childhood respiratory infection on adult BHR, but this was small in comparison to relations of BHR to IgE-sensitization and airway caliber.