Background: Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthmatic patients are lacking. Objective: We sought to investigate pollution effects in a longitudinal asthma study and effect modification by controller medications. Methods: We examined associations of lung function and methacholine responsiveness (PC20) with ozone, carbon monoxide (CO), nitrogen dioxide, and sulfur dioxide concentrations in 1003 asthmatic children participating in a 4-year clinical trial. We further investigated whether budesonide and nedocromil modified pollution effects. Daily pollutant concentrations were linked to ZIP/postal code of residence. Linear mixed models tested associations of within-subject pollutant concentrations with FEV1 and forced vital capacity (FVC) percent predicted, FEV1/FVC ratio, and PC20, adjusting for seasonality and confounders.
Ierodiakonou, D., Zanobetti, A., Coull, B. A., Melly, S., Postma, D. S., Boezen, H. M., … Gold, D. R. (2016). Ambient air pollution, lung function, and airway responsiveness in asthmatic children. Journal of Allergy and Clinical Immunology, 137(2), 390–399. https://doi.org/10.1016/j.jaci.2015.05.028