The Danish Cancer Society, Institute of Cancer Epidemiology, Strandboulevarden 49, 2100 Copenhagen, Denmark.
Eur Heart J. 2010 Aug;31(16):2034-40. doi: 10.1093/eurheartj/ehq188. Epub 2010 Jun 10.
The relevance of ultrafine particles (UFPs, particles <0.1 microm diameter), the smallest fraction of ambient particulate matter, on stroke morbidity has not been documented. We studied the effects of short-term changes in exposure to these particles on stroke, separately for ischaemic and haemorrhagic strokes, mild and severe strokes, and ischaemic strokes with (likely embolic) and without (likely thrombotic) atrial fibrillation (AF).
We used a time-stratified case-crossover design to study the association between short-term exposure to UFPs, particulate matter <10 microm in diameter (PM(10)), nitrogen oxides (NO(x)) and carbon monoxide (CO) (measured at single background station) and hospital admissions for stroke in Copenhagen (2003-2006). Of 7485 stroke admissions, 6798 were ischaemic and 687 haemorrhagic, 3485 mild, and 2248 severe. Of the ischaemic stroke cases, 1204 had AF and 5273 did not. We found significant positive association with exposure to UFPs, NO(x) and CO, and ischaemic strokes, and UFPs and NO(x) and mild strokes, 4 days before admission. The strongest associations were with UFPs. Exposure to UFPs lead to a 21% increase in hospital admissions (per interquartile range of 5-day averages; 95% confidence interval 4-41%) for mild ischaemic stroke of without AF (likely thrombotic origin).
Our results indicate possible effects of traffic-related air pollution, mainly UFPs, on hospital admissions for ischaemic stroke, especially for mild ischaemic stroke of likely thrombotic origin (without AF). These are novel findings regarding the relevance of UFPs and the heterogeneous effect of air pollution on the severity and origin of stroke, and need confirmation by other data.
超细颗粒（UFPs，直径<0.1 微米的颗粒）是环境颗粒物中最小的一部分，其与中风发病率之间的相关性尚未得到证实。我们研究了短期暴露于这些颗粒对中风的影响，分别针对缺血性和出血性中风、轻度和重度中风，以及伴有（可能为栓塞性）和不伴有（可能为血栓性）心房颤动（AF）的缺血性中风。
我们使用时间分层病例交叉设计来研究短期暴露于 UFPs、直径<10 微米的颗粒物（PM（10））、氮氧化物（NOx）和一氧化碳（CO）（在单个背景站测量）与哥本哈根（2003-2006 年）因中风住院之间的关联。在 7485 例中风住院患者中，6798 例为缺血性，687 例为出血性，3485 例为轻度，2248 例为重度。在缺血性中风病例中，1204 例有 AF，5273 例没有。我们发现，在入院前 4 天，暴露于 UFPs、NOx 和 CO 与缺血性中风以及 UFPs 和 NOx 与轻度中风之间存在显著的正相关关系。与其他污染物相比，与 UFPs 的相关性最强。暴露于 UFPs 导致轻度无 AF（可能为血栓性起源）缺血性中风的住院人数增加 21%（五分位距 5 天平均值的差异；95%置信区间 4-41%）。
我们的研究结果表明，交通相关空气污染，主要是 UFPs，可能对缺血性中风的住院人数产生影响，特别是对无 AF（可能为血栓性起源）的轻度缺血性中风。这些是关于 UFPs 的相关性以及空气污染对中风严重程度和起源的异质影响的新发现，需要其他数据进行证实。
