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Air pollution interacts with past episodes of bronchiolitis in the development of asthma
Author(s) -
Kim B. J.,
Seo J. H.,
Jung Y. H.,
Kim H. Y.,
Kwon J. W.,
Kim H. B.,
Lee S. Y.,
Park K. S.,
Yu J.,
Kim H. C.,
Leem J. H.,
Lee J. Y.,
Sakong J.,
Kim S. Y.,
Lee C. G.,
Kang D. M.,
Ha M.,
Hong Y. C.,
Kwon H. J.,
Hong S. J.
Publication year - 2013
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/all.12104
Subject(s) - bronchiolitis , asthma , medicine , odds ratio , allergy , confidence interval , pediatrics , environmental health , respiratory system , immunology
Background Exposure to ambient air pollution and bronchiolitis are risk factors for asthma. The aim of this study was to investigate the effect of air pollution on the development of asthma in children with past episodes of bronchiolitis. Methods A prospective 2‐year follow‐up survey consisting of parental responses to the I nternational S tudy of A sthma and A llergies in C hildhood ( ISAAC ) questionnaire, and allergy evaluations were conducted in 1743 children with a mean age of 6.8 years. Recent 5‐year exposure to air pollution was estimated using a geographic information system. Results Higher exposure to ozone was associated with airway hyper‐responsiveness ( PC 20 ≤ 16 mg/ml) at enrollment (odds ratio [ OR ] = 1.60, 95% CI [confidence interval] = 1.13–2.27) and with new episodes of wheezing during the 2‐year period ( OR = 1.92, 95% CI = 0.96–3.83). Past episodes of bronchiolitis were associated with both current wheezing and physician‐diagnosed asthma. When the two factors were combined, the prevalence of bronchial hyper‐reactivity ( OR = 2.96, 95% CI = 1.41–6.24) and new wheezing ( OR = 4.17, 95% CI = 0.89–19.66) as well as current wheezing and physician‐diagnosed asthma was even greater ( P for trend <0.05 for all). In children with both risk factors, lung function was significantly decreased, with atopic children being particularly vulnerable. Conclusion In children, the interaction between air pollution and past episodes of bronchiolitis resulted in a greater prevalence of asthma and pointed to an association with bronchial hyper‐reactivity and decreased lung function. These results suggest mechanisms underlying the development of asthma.