Public Health GIS Unit, School of Health and Related Research, University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK.
Int J Health Geogr. 2014 Jun 17;13:23. doi: 10.1186/1476-072X-13-23.
Evidence linking outdoor air pollution and incidence of ischemic stroke subtypes and severity is limited. We examined associations between outdoor PM10 and NO2 concentrations modeled at a fine spatial resolution and etiological and clinical ischemic stroke subtypes and severity of ischemic stroke.
We used a small-area level ecological study design and a stroke register set up to capture all incident cases of first ever stroke (1995-2007) occurring in a defined geographical area in South London (948 census output areas; population of 267839). Modeled PM10 and NO2 concentrations were available at a very fine spatial scale (20 meter by 20 meter grid point resolution) and were aggregated to output area level using postcode population weighted averages. Ischemic stroke was classified using the Oxford clinical classification, the Trial of Org 10172 in Acute Stroke Treatment (TOAST) etiological classification, National Institutes of Health Stroke Scale (NIHSS) score and a pragmatic clinical severity classification based on Glasgow coma score, ability to swallow, urinary continence and death <2 days of stroke onset.
Mean (SD) concentrations were 25.1 (1.2) ug/m(3) (range 23.3-36.4) for PM10 and 41.4 (3.0) ug/m(3) (range 35.4-68.0) for NO2. There were 2492 incident cases of ischemic stroke. We found no evidence of association between these pollutants and the incidence of ischemic stroke subtypes classified using the Oxford and TOAST classifications. We found no significant association with stroke severity using NIHSS severity categories. However, we found that outdoor concentrations of both PM10 and NO2 appeared to be associated with increased incidence of mild but not severe ischemic stroke, classified using the pragmatic clinical severity classification. For mild ischemic stroke, the rate ratio in the highest PM10 category by tertile was 1.20 (1.05-1.38) relative to the lowest category. The rate ratio in the highest NO2 category was 1.22 (1.06-1.40) relative to the lowest category.
We found no evidence of association between outdoor PM10 and NO2 concentrations and ischemic stroke subtypes but there was a suggestion that living in areas with elevated outdoor PM10 and NO2 concentrations might be associated with increased incidence of mild, but not severe, ischemic stroke.
将户外空气污染与缺血性中风亚型和严重程度联系起来的证据有限。我们研究了在精细空间分辨率下建模的户外 PM10 和 NO2 浓度与病因学和临床缺血性中风亚型以及缺血性中风严重程度之间的关系。
我们使用小区域水平的生态研究设计和一个中风登记处，该登记处旨在捕获发生在伦敦南部一个特定地理区域内的所有首次中风病例（1995-2007 年）（948 个普查输出区；人口 267839 人）。PM10 和 NO2 浓度的模型可在非常精细的空间尺度上获得（20 米×20 米网格点分辨率），并通过邮政编码人口加权平均值汇总到输出区级别。缺血性中风采用牛津临床分类、组织 10172 急性中风治疗试验（TOAST）病因分类、美国国立卫生研究院中风量表（NIHSS）评分和基于格拉斯哥昏迷评分、吞咽能力、尿失禁和发病后 2 天内死亡的实用临床严重程度分类进行分类。
PM10 的平均（标准差）浓度为 25.1（1.2）μg/m3（范围为 23.3-36.4），NO2 的浓度为 41.4（3.0）μg/m3（范围为 35.4-68.0）。共有 2492 例缺血性中风病例。我们没有发现这些污染物与使用牛津和 TOAST 分类的缺血性中风亚型之间存在关联的证据。我们没有发现 NIHSS 严重程度分类与中风严重程度之间存在显著关联。然而，我们发现，使用实用临床严重程度分类，户外 PM10 和 NO2 的浓度似乎与轻度但非重度缺血性中风的发生率增加有关。对于轻度缺血性中风，最高 PM10 类别的比率比最低类别高 1.20（1.05-1.38）。最高 NO2 类别的比率比最低类别高 1.22（1.06-1.40）。
我们没有发现户外 PM10 和 NO2 浓度与缺血性中风亚型之间存在关联的证据，但有迹象表明，生活在户外 PM10 和 NO2 浓度较高的地区可能与轻度但非重度缺血性中风的发生率增加有关。
