Investigating Overweight/Obesity as a Susceptibility Factor for Secondhand Smoke in Childhood Asthma

项目摘要 儿童哮喘和肥胖是美国紧迫的健康流行病， 对来自低收入家庭的少数群体儿童的影响尤为严重。哮喘 在肥胖儿童中往往更严重且难以治疗。一个新兴的解释性假设是 这些儿童可能更容易受到空气污染的影响。二手烟占主导地位 室内空气污染源，特别是在市中心，高达80%的哮喘儿童 经常暴露。二手烟对体重的不同影响尚不清楚。 我们假设二手烟对超重或肥胖的儿童更有害 与哮喘的关系，并且这种关系可能与炎症和氧化应激的差异有关。 因为肥胖与炎症基础水平升高有关，哮喘与 增强炎症和氧化应激，我们认为这是一个合理的生物学机制。 我们发现了来自国家健康和营养委员会的令人信服的初步证据， 检查调查（NHANES），超重或肥胖的儿童报告更大的症状时， 与正常体重的儿童相比，该项目扩展了这一成果， 分析到地方一级，在更明确的儿童群体谁有症状和血液 生物标志物评估。本研究将在（1）两个大型观察性队列的儿童中进行， 哮喘，比较那些谁是和不暴露于二手烟，并在（2）干预 一组哮喘儿童，他们都暴露于二手烟， 二手烟暴露通过使用先进的空气净化器，比较哮喘的差异 体重正常者与超重或肥胖者之间的改善。 由于身体质量指数是一个不完美的肥胖标志物，本项目还将研究是否有其他不同的 通过生物电阻抗估计的肥胖、腰围和体脂百分比的测量 分析，比身体质量指数更好地识别这一弱势群体。

PROJECT SUMMARY Childhood asthma and obesity are pressing health epidemics in the United States that disproportionately impact children who are minorities and come from households with lower incomes. Asthma in obese children tends to be more severe and refractory to treatment. An emerging explanatory hypothesis is that these children may be more vulnerable to components of air pollution. Secondhand smoke is a dominant source of indoor air pollution, particularly in the inner city, where up to 80% of children with asthma are regularly exposed. The differential effects of secondhand smoke based on weight are not known. We hypothesize that secondhand smoke is preferentially deleterious to overweight or obese children with asthma, and that this relationship may correlate with differences in inflammation and oxidative stress. Because obesity is associated with basal elevations in inflammation and because asthma is associated with enhanced inflammation and oxidative stress, we believe that this is a plausible biologic mechanism. We have discovered compelling preliminary evidence from the National Health and Nutrition Examination Survey (NHANES) that children who are overweight or obese report greater symptoms when exposed to secondhand smoke as compared to normal weight children. This project extends the results of this analysis to a local level, in more well-characterized cohorts of children who have both symptom and blood biomarker assessment. This study will be performed in (1) two large observational cohorts of children with asthma, comparing those who are and are not exposed to secondhand smoke, and in (2) an interventional cohort of children with asthma who are all exposed to secondhand smoke and have subsequent reductions in secondhand smoke exposure through the use of an advanced air purifier, comparing differences in asthma improvement between those who are normal weight and overweight or obese. As body mass index is an imperfect marker for adiposity, this project will also examine if other different measures of adiposity, waist circumference and percentage body fat as estimated by bioelectrical impedance analysis, perform better than body mass index in identifying this vulnerable group.