Air Pollution and Preclinical Atherosclerosis in Elementary-School Children

描述（由申请人提供）：环境空气污染与心血管死亡率和发病率相关，是全身性炎症的原因。炎症是动脉粥样硬化的标志，动脉粥样硬化是心血管疾病（CVD）的主要潜在病理生理。空气污染与亚临床动脉粥样硬化之间的显著关联已在成人中报道，使用超声测量颈动脉壁厚度。颈动脉内膜-中膜厚度（CIMT）是亚临床动脉粥样硬化的标志。CIMT从出生开始逐渐增加，与生命早期的亚临床炎症有关，是CVD的一个强有力的决定因素。本项目的假设是，长期暴露于来自室外的局部和区域空气污染物会促进早期生活中的动脉粥样硬化，从而导致10-12岁儿童的CIMT差异。将对来自南加州13个社区的650名儿童的CIMT和协变量进行评估。将从一项正在进行的关于空气污染与健康的队列研究中选择来自非吸烟家庭的终身居民。平均而言，儿童在家里和学校度过的时间超过80%。因此，暴露评估将基于在室内、每个儿童的家和学校以及选定的室外地点测量的室外细颗粒物（PM2.5）。哈佛大学的长期采样器将收集PM2。在9个月的时间里，在每个地点进行了调查。PM2的反射率。s是当地移动源排放的标志，硫质量是区域pm2.5的标志。在家里和学校的室内时间、通勤时间和户外活动时间将通过问卷进行评估。微环境浓度和时间-活动信息将提供输入，以确定每个儿童对当地和区域污染的暴露情况。CIMT与个人终生暴露于局部和区域室外污染之间的关系将在多水平空间回归模型中进行分析。相关性：美国心脏协会建议关注儿童动脉粥样硬化的预防。炎症性空气污染物无处不在，数百万美国儿童生活在超过当前政府标准的地区。暴露于当地和区域环境污染物会影响儿童的CIMT，这在生物学上是合理的。年轻时CIMT的微小差异会在以后的生活中转化为临床相关的CVD -这是美国发病率和死亡率的主要原因

DESCRIPTION (provided by applicant): Ambient air pollution correlates with cardiovascular mortality and morbidity and is a cause of systemic inflammation. Inflammation is the hallmark of atherosclerosis, which is the primary underlying pathophysiology of cardiovascular diseases (CVD). Significant associations between air pollution and subclinical atherosclerosis have been reported in adults, using sonographically measured thickness of the carotid artery wall. Carotid intima-media thickness (CIMT) is an established marker of subclinical atherosclerosis. CIMT gradually increases from birth, is associated with subclinical inflammation in early life, and is a strong determinant of CVD. This project pursues the hypothesis that long-term exposure to local and regional air pollutants from outdoor origin promotes atherogenesis in early life, leading to differences in CIMT in 10-12yr old children. CIMT and covariates will be assessed among 650 children followed up from 13 Southern California communities. Lifetime residents from non-smoking households will be selected from an ongoing cohort study on air pollution and health. On average, children spend more than 80% of their time indoors at home and in school. Thus, exposure assessment will be based on fine particulate matter (PM2.5) from outdoor origin measured indoors in the home and school of each child and in selected outdoor locations. A Harvard long-term sampler will collect PM2.s in each location over a period of nine months. Light reflectance of PM2.s serves as a marker of local mobile source emissions and sulfur mass indicates regional PM2.s. Time spent indoors at home and school, in commuting, and in outdoor activities will be assessed by questionnaire. The microenvironmental concentrations and time-activity information will provide the input to derive exposure to local and regional pollution for each child. Associations between CIMT and personal lifetime exposure to local and regional outdoor pollution will be analyzed in multilevel spatial regression models. Relevance: The American Heart Association recommends focusing on prevention of atherosclerosis in children. Inflammatory air pollutants represent ubiquitous exposures, and millions of American children live in areas that exceed current government standards. It is biologically plausible that exposure to local and regional ambient pollutants effects CIMT in children. Small differences in CIMT at a young age translate into clinically relevant CVD later in life - the leading cause of morbidity and mortality in the U.S.