Effects of stress and the social environment on childhood asthma in the children' s health study

UnrestrictedChildhood asthma prevalence is often higher in areas of low socioeconomic status (SES), but such disparities are not explained by individual-level risk factors. Unexplained geographic variation in asthma may reflect an incomplete understanding of asthma etiology. In particular, there is growing interest in the role of chronic stress in the development of asthma. A series of analyses examined associations of asthma with areas of low SES and an indicator of stress using data from two cohorts of the Children 's Health Study based in Southern California. In the first analysis, children with higher parental stress were significantly more susceptible to the effects of two sources of reactive oxygen species, traffic-related pollution and in utero tobacco smoke exposure, on incident asthma, which suggests that oxidative stress pathways may be important for the development of asthma. In the second analysis, children from communities with high male unemployment were 12% less likely to report lifetime asthma after adjusting for individual-level risk factors. However, additional analyses in this same study population suggested that children from communities with high male unemployment and poverty may be at increased risk for incident asthma, indicating that results from cross-sectional versus prospective studies may be less accurate and/or negatively biased.; In the third analysis, increased risk for incident asthma was observed in subjects attending schools receiving Title I funds compared to those from schools without funding (HR 1.71, 95% CI 1.14-2.58), and residing in communities with higher rates of larceny crime (HR 1.31, 95% CI 1.08-1.60 across interquartile range of 570 incidents per 100,000 population). These results were not explained by individual-level risk factors for asthma, although the effect of the larceny crime rate was partially positively confounded by residential exposure to traffic-related pollution. Increased risk for asthma in areas of low SES may be related to unmeasured factors of the physical environment found in areas of high deprivation, or they may be a marker for stressful environments. These results indicate that further investigation of the social environment could both elucidate the role of risk factors such as stress in mediating contextual effects and identify new avenues for disease prevention