Physical Activity and Dose of Air Pollution in Pediatric Urban Asthma: Impact of Minute Ventilation

项目摘要 暴露于交通相关的空气污染（TRAP）是已知的引发儿童哮喘 症状，并可能导致哮喘患病率和发病率的差异，在城市 社区.定期的体育活动可以改善哮喘症状。然而，增加 活动期间的每分钟通气量（即呼吸率x潮气量）可能会增加 污染物颗粒进入呼吸道。因此，污染可能会抵消身体健康对呼吸的好处。 活动准确评估污染和环境污染的综合影响的挑战之一是， 呼吸道上的活动是，污染物的吸入剂量可能因暴露的接近程度而异 源和分钟通气量的个体差异。因此，我们的目标是 评估儿童活动期间分钟通气量变化的个体化方法， 还考虑到家庭和学校接触TRAP的可变性。 我们假设接触TRAP和哮喘之间的正相关性 症状将是最显着的儿童是1）高度体力活动和2） 每分钟通气量会随着身体活动而增加。为了解决 这一假设，我们将利用现有的2个儿童队列， 参加内城哮喘联盟（ICAC）研究的哮喘患者。我们的第一个目标 我们将研究接触TRAP（在家中和学校评估）之间的相互作用， 使用地理信息系统（GIS）技术）和身体活动（由 经验证的问卷）。我们将在以下方面评估这些关联：1）a 320例中重度哮喘患者的横断面队列，年龄6-17岁，居住在美国10个城市 城市和2）150名轻中度哮喘患者的3年纵向队列，年龄12-16岁， 美国4个城市。对于我们的第二个目标，我们将招募40名轻度- 住在纽约市的中度哮喘患者我们会将联合收割机 运动试验（CPET），采用72小时加速度计测量，以确定幅度 增加每分钟通气量，以响应通常的儿童活动。然后我们将使用 这些值用于确定每分钟通气量的较大个体增加是否影响 TRAP暴露与哮喘症状之间的关系。具有增强 了解个体对环境引发哮喘的易感性，我们将更好地 有能力解决和补救城市居民中哮喘发病率不成比例的风险， 孩子

PROJECT SUMMARY Exposure to traffic related air pollution (TRAP) is known to trigger childhood asthma symptoms and likely contributes to the disparity in asthma prevalence and morbidity in urban communities. Regular physical activity can improve asthma symptoms. However, increased minute ventilation (ie respiratory rate x tidal volume) during activity may increase deposition of pollutant particles into the airways. Thus, pollution may offset the respiratory benefits of physical activity. One of the challenges of accurately assessing the combined effects of pollution and activity on the airways is that inhaled dose of pollutants could vary by proximity to exposure source and by individual differences in minute ventilation. Therefore, our objective is take an individualized approach to assess change in minute ventilation during childhood activities while also considering variability in home and school exposure to TRAP. We hypothesize that the positive association between exposure to TRAP and asthma symptoms will be most significant among children that are 1) highly physically active and 2) have larger increases in minute ventilation in response to physical activity. In order to address this hypothesis we will take advantage of 2 existing cohorts of children with differing severity of asthma that are enrolled in the Inner City Asthma Consortium (ICAC) studies. For our first aim we will examine the interaction between exposure to TRAP (assessed at home and school using geographic information systems (GIS) technology) and physical activity (assessed by validated questionnaire) on asthma symptoms. We will evaluate these associations in: 1) a cross-sectional cohort of 320 moderate-severe asthmatics, ages 6-17 that live in 10 urban US cities and 2) a 3 year longitudinal cohort of 150 mild-moderate asthmatics, ages 12-16 that live in 4 urban US cities. For our second aim we will recruit a sub-sample of 40 children with mild- moderate asthma that live in New York City. We will combine individual cardiopulmonary exercise testing (CPET) with 72-hour accelerometry measurements to determine the magnitude of increase in minute ventilation in response to usual childhood activities. Then we will use these values to determine if larger individual increases in minute ventilation influence the relationship between exposure to TRAP and asthma symptoms. With an enhanced understanding of individual susceptibility to environmentally triggered asthma, we will be better equipped to address and remediate the disproportionate risk of asthma morbidity among urban children.