Influences of Asthma and Household Environment on Lung Function of Children and Adolescents: the Third National Health and Nutrition Examination Survey
We examined influences of asthma and household environment (passive smoking, gas stove use, and having a dog or cat), on seven measures of spirometric lung function in 8-16 yearold subjects, as measured in the Third National Health and Nutrition Examination Survey (NHANES III). In regression models, independent variables included age, anthropometric measurements, asthma status, and household environmental factors. Regressions were weighted by the NHANES III examination sample weighting factor, and were adjusted for clustering in the sampling design. There were distinct gender differences in results. In girls, lung function was lowest in active asthmatics taking prescription respiratory medicine, whereas lung function in other active and inactive asthmatics did not differ greatly from that in non-asthmatics. In boys, however, all asthmatic groups had substantially lower lung function than non-asthmatics. Lung function differences between active asthmatics and non-asthmatics were stable with increasing age. However, lung function of inactive asthmatic girls and boys returned to, and diverged from, non-asthmatics' levels, respectively. In asthmatic girls, passive smoking was associated with increased lung function, and gas stove use was associated with reduced lung function in subjects not taking prescription respiratory medicine.