Ambient Particles and Ischemic and Hemorrhagic Stroke

描述（由申请人提供）：中风是美国和加拿大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。许多流行病学研究发现，颗粒空气污染的短期增加与心血管发病率和死亡率之间存在关联。暴露于颗粒物也可能增加缺血性和/或出血性中风的风险，但这一假设仅通过行政记录或死亡证明的数据进行了检验。通过对加拿大安大略省12个医疗中心2003年至2008年间住院治疗的16000名急性中风患者进行前瞻性研究质量数据的病例交叉研究，我们旨在验证以下假设：1)环境颗粒物水平的短期增加可以加速急性缺血性和出血性中风的发作；2)在极短期暴露（小时）和中期暴露（天）后，暴露于环境颗粒物到中风症状发作的诱导时间将可量化；3)患有心血管合并症的患者，包括II型糖尿病、既往中风和冠状动脉疾病，最容易受到这些影响。患者数据将从加拿大卒中网络（RCSN）基于人群的登记处获得。个人暴露于环境颗粒物和其他环境污染物的情况将使用居住地的邮政编码和来自参与医院集水区空气质量监测仪的每小时监测数据进行评估。通过更好地量化环境空气污染与特定中风亚型之间的关系，并通过确定易感人群，该项目的结果可能为未来的机制研究规划提供信息，并可能对中风预防产生影响。与以往的研究相比，该应用程序提供了几个优势，包括大量未选择的急性中风（缺血性和出血性）患者中风症状发作时间和重要临床协变量的信息。此外，该应用程序反映了与加拿大中风网络研究人员的新合作，并为未来的合作项目奠定了基础。公共卫生相关性：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。有证据表明，空气微粒污染的短期增加可能会引发一些人中风。在这项研究中，我们将评估16,000名中风患者，以评估空气污染作为中风发作的潜在触发因素的影响。

DESCRIPTION (provided by applicant): Stroke is a leading cause of long-term disability in the United States and Canada and the third leading cause of death after heart disease and cancer. Many epidemiologic studies have found an association between short-term increases in particulate air pollution and cardiovascular morbidity and mortality. Exposure to particulate matter may also increase the risk of ischemic and/or hemorrhagic stroke, but this hypothesis has only been examined using data from administrative records or death certificates. By conducting a case-crossover study using prospectively collected research-quality data from >16,000 patients hospitalized between 2003 and 2008 with acute stroke in 12 medical centers across Ontario, Canada, we aim to test the following hypotheses: 1) Short-term increases in ambient levels of particulate matter can precipitate the onset of acute ischemic and hemorrhagic stroke; 2) the induction time from ambient particulate matter exposure to the onset of stroke symptoms will be quantifiable after very short-term exposures (hours) and after intermediate-term exposure (days); 3) patients with cardiovascular co-morbid conditions including type II diabetes, previous stroke and coronary artery disease will be most susceptible to these effects. Patient data will be obtained from the population-based Registry of the Canadian Stroke Network (RCSN). Individuals' exposures to ambient particulate matter and other ambient pollutants will be assessed using postal code of residence and hourly monitoring data from air quality monitors located in the catchment areas of participating hospitals. By better quantifying the relationship between ambient air pollution and specific stroke subtypes and by identifying susceptible populations, the results of this project may inform the planning of future mechanistic studies and may have implications for stroke prevention. This application offers several advantages over previous studies, including information on the timing of stroke symptom onset and important clinical covariates in a very large number of unselected patients with acute stroke (ischemic and hemorrhagic). Moreover, this application reflects a new collaboration with investigators from the Canadian Stroke Network and lays the groundwork for future collaborative projects. PUBLIC HEALTH RELEVANCE: Stroke is a leading cause of long-term disability in the United States and the third leading cause of death after heart disease and cancer. There is some evidence that short-term increases in particulate air pollution may trigger the onset of stroke in some people. In this study, we will evaluate 16,000 patients with stroke to evaluate the effect of air pollution as a potential trigger of stroke onset.