Effect of Ambient Particles on Acute Stroke Onset

中风是美国长期残疾的主要原因，也是仅次于心脏病和癌症的第三大死亡原因。识别中风发作的触发因素具有重大的公共卫生意义。许多流行病学研究发现，空气颗粒污染的短期增加与心血管疾病发病率和死亡率之间存在关联。这些影响可能是由吸入颗粒引起的神经、血液和炎症反应介导的。暴露于颗粒物也可能增加缺血性卒中的风险。最近使用行政数据库进行的研究报告了相同的结果。因此，本项目的目标是定量评估环境颗粒物短期增加与急性缺血性卒中风险之间的关联。具体地说， 我们将评估：1）颗粒物短期增加与急性缺血性卒中风险之间的相关性，2）该效应的时间过程，3）最可能导致该效应的环境颗粒物的特定成分，以及4）缺血性卒中病因亚型的效应幅度变化。为了实现这些目标，我们将使用PPG Cores的服务和专业知识，并将病例交叉方法应用于1200例急性缺血性卒中住院患者的研究。尽管任何影响的程度预计都很小，但考虑到大量人群同时处于中风风险和暴露于城市空气污染中，归因风险可能相当显著。澄清颗粒空气污染对中风发作的影响对监管机构来说很重要。此外，关于影响的时间过程和重要颗粒的识别的信息 这些成分可以提供对颗粒物诱导的心血管事件的机制的洞察。

Stroke is a leading cause of long-term disability in the US and the third leading cause of death after heart disease and cancer. The identification of triggers of stroke onset is of significant public health interest. Many epidemiologic studies have found an association between short-term increases in particulate air pollution and cardiovascular morbidity and mortality. These effects are likely mediated by neural, hematologic, and inflammatory responses to inhaled particles. Exposure to particulate matter may also increase the risk of ischemic stroke. Recent studies using administrative databases have reported equivical results. Accordingly, the goal of this Project is to quantitatively evaluate the association between short-term increases in ambient particulate matter and the risk of acute ischemic stroke. Specifically, we will evaluate: 1) the association between short-term increases in particulate matter and the risk of acute ischemic stroke, 2) the time course of this effect, 3) the specific constituents of ambient particulate matter to which the effect is most likely attributable, and 4) variation in effect magnitude by etiological subtype of ischemic stroke. To accomplish these aims we will use the services and expertise of the PPG Cores and will apply the case-crossover methodology to the study of 1200 patients hospitalized with acute ischemic stroke. Even though the magnitude of any effect is expected to be small, given the large number of people simultaneously at risk for stroke and exposed to urban air pollution, the attributable risk may be quite significant. Clarifying the impact of particulate air pollution on stroke onset is important for regulatory agencies. Additionally, information about the time course of the effect and identification of important particle constituents may provide insight into the mechanisms of particulate-induced cardiovascular events.