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）的主要基础病理生理学。通过超声测量颈动脉壁的厚度，已经报道了成人中空气污染和亚临床动脉粥样硬化之间的显著关联。颈动脉内膜中层厚度（CIMT）是亚临床动脉粥样硬化的既定标志物。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。该项目追求的假设是，长期暴露于来自户外的局部和区域空气污染物会促进生命早期的动脉粥样硬化形成，导致10- 12岁儿童CIMT的差异。将在来自南加州13个社区的650名随访儿童中评估CIMT和协变量。来自非吸烟家庭的终身居民将从一项正在进行的空气污染与健康的队列研究中选出。平均而言，儿童在家中和学校的时间超过80%。因此，暴露评估将基于在每个儿童的家中和学校室内以及选定的室外地点测量的来自室外的细颗粒物（PM2.5）。一个哈佛长期采样器将在九个月的时间内收集每个地点的PM2. s。PM2. s的光反射率用作本地移动的源排放的标志，并且硫质量指示区域PM2. s。将通过问卷调查评估在家和学校的室内时间、通勤时间和户外活动时间。微环境浓度和时间-活动信息将提供投入，以得出每个儿童接触当地和区域污染的情况。CIMT和个人终生暴露于当地和区域性室外污染之间的关联将在多层次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。炎症性空气污染物代表着无处不在的暴露，数百万美国儿童生活在超过现行政府标准的地区。从生物学角度来看，暴露于当地和区域环境污染物会影响儿童的CIMT。年轻时CIMT的微小差异在以后的生活中转化为临床相关的CVD-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.