Indoor and Outdoor Environmental Exposures, Parental Atopy, and Physician-Diagnosed Asthma in Taiwanese Schoolchildren

Abstract

ABSTRACT. Objective. Parental atopy and environmental exposures are recognized risk factors for childhood asthma. However, the relative contributions of specific risk factors and the overall contributions of indoor and outdoor exposures remain unexplored. This study was undertaken to identify risk factors, estimate the population attributable risk of each exposure, and compare the data for boys versus girls for physician-diagnosed asthma in Taiwanese schoolchildren.Methods. During a February to June 2001 cross-sectional national survey, 35 036 6-to 15-year-old schoolchildren were chosen from 22 elementary and 22 middle schools located within 1-km catchment areas of 22 airmonitoring stations in Taiwan. The main outcome measure was physician-diagnosed asthma, as reported by the parents. We investigated hereditary and indoor and outdoor environmental factors for childhood asthma by questionnaire. The adjusted prevalences of questionnaire-determined outdoor indicators were also compared with air-monitoring data.Results. Outdoor air pollutants were associated with parent-reported perceived ambient air pollution. Physician-diagnosed asthma was reported for 8.1% of the boys (1330 of 16 441) and 5.6% of the girls (894 of 16 056). The risk of physician-diagnosed asthma was significantly associated with parental atopy and perceived ambient air pollution in both sexes. A sthma is the single most common chronic childhood disease in developed nations, 1,2 and its prevalence and severity have been reported as increasing in many countries. [3][4][5][6] The changing pattern of the disease has not been fully explained, in part because of an incomplete understanding of its pathogenesis. The change has been too rapid to be accounted for by changes in gene frequencies. It is also unlikely that the increase can be totally accounted for by changes in either clinical diagnostic patterns or increased recognition of asthma symptoms by the general population. 7 This does, however, suggest a role for environmental exposures in the cause of this evolving epidemic. 8 Many factors have been proved to be associated with the prevalence and/or attacks of asthma, including personal factors (smoking habits, genetics, age, sex, nutritional status, number of siblings, coexisting lung disease, lifestyle, allergy status, family history, and occupation) and environmental stimuli (house dust, animal danders, molds, cockroach infestation, occupational exposure, environmental tobacco smoke, indoor/outdoor air pollution, cooking fumes, aeroallergens, and climate). 9 -29 Both genetic and environmental factors are believed to contribute to the relationship. However, epidemiologic evidence concerning different effects in boys and girls in relationships between environmental exposures and childhood asthma was insufficient and warranted additional investigations.The first aim of this study was to investigate the relationship between physician-diagnosed asthma and selected risk factors in a population-based sample of 6-to 15-year-old elementary-and middleschool...

Vitamin D Deficiency as a Strong Predictor of Asthma in Children

“…Similar trends have recently been reported in the Asia-Pacific areas [5,6,7] and Arabian Gulf countries [1,2,3,4,6,8]. Asthma is one of the most common chronic diseases in Saudi Arabia, affecting more than 2 million people [9].…”

Tumour necrosis factor G-308A polymorphism modifies the effect of home dampness on childhood asthma

“…Age, sex, active smoking habits, parental atopic history, parental education, maternal smoking in pregnancy and ETS exposure at home have been reported to contribute to asthma and wheeze in childhood 6 22 25. We minimised interference from these confounders by recruiting lifelong non-smokers of similar age at study entry, and adjusting potential confounders by regression models.…”

Association between Chlamydia pneumoniae antibodies and wheezing in young children and the influence of sex

“…It has been suggested that girls are more susceptible to selected non-allergen effects in their airways, and are thus possibly more susceptible to reactive airway disease when infected with Cpn. [23][24][25] Another explanation could be that some individuals, most often girls, might have an impaired ability to eliminate Cpn when infected. 26 If persistently infected over an extended period of time, the immune system might respond with higher levels of antibodies to Cpn which may not be protective.…”