Long term exposure to ambient fine particulate matter and incidence of stroke: prospective cohort study from the China-PAR project

• Type of Material: Article
• Authors: Keyong Huang, Chinese Academy of Sciences; Fengchao Liang, Chinese Academy of Sciences; Xueli Yang, Chinese Academy of Sciences; Jianxin Li, Chinese Academy of Sciences; Qingyang Xiao, Tsinghua University; Jichun Chen, Chinese Academy of Sciences; Jie Cao, Chinese Academy of Sciences; Chong Shen, Nanjing Medical University; Ling Yu, Fujian Provincial Hospital; Fanghong Lu, Shandong Academy of Medical Sciences; Xianpinq Wu, Sichuan Center for Disease Control and Prevention; Liancheng Zhao, Chinese Academy of Sciences; Xigui Wu, Chinese Academy of Sciences; Ying Li, Chinese Academy of Sciences; Dongsheng Hu, Shenzhen University; Jianfeng Huang, Chinese Academy of Sciences; Yang Liu, Emory University; Xiangfeng Lu, Chinese Academy of Sciences; Dongfeng Gu, Chinese Academy of Sciences
• Language: English
• Date: 2019-12-30
• Publisher: BMJ Publishing Group
• Publication Version: Final Published Version
• Copyright Statement: © 2019 BMJ Publishing Group Ltd.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1136/bmj.l6720
• Title of Journal or Parent Work: BMJ: British Medical Journal
• Volume: 367
• Start Page: l6720
• End Page: l6720
• Grant/Funding Information: This work was supported by the National Key Research and Development Program of China (2017YFC0211703, and 2016YFC0206503), National Natural Science Foundation of China (91643208), Chinese Academy of Medical Science Innovation Fund for Medical Sciences (2017-I2M-1-004), and the China Medical Board (15-220).
• Keywords: Trends; Blood pressure; Life Sciences & Biomedicine; Medicine, General & Internal; PM2.5 concentrations; Science & Technology; Mortality; Air pollution; Risk; General & Internal Medicine; Cardiovascular disease; Global burden; Association; Events
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Public Health; Health Sciences, Occupational Health and Safety; Environmental Sciences

Abstract

Objective: To study the effect of long term exposure to ambient fine particulate matter of diameter ≤2.5 μm (PM 2.5) on the incidence of total, ischemic, and hemorrhagic stroke among Chinese adults. Design: Population based prospective cohort study. Setting: Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project carried out in 15 provinces across China. Participants: 117 575 Chinese men and women without stroke at baseline in the China-PAR project. Main outcome measures: Incidence of total, ischemic, and hemorrhagic stroke. Results: The long term average PM 2.5 level from 2000 to 2015 at participants' residential addresses was 64.9 μg/m 3, ranging from 31.2 μg/m 3 to 97.0 μg/m 3. During 900 214 person years of follow-up, 3540 cases of incident stroke were identified, of which 63.0% (n=2230) were ischemic and 27.5% (n=973) were hemorrhagic. Compared with the first quarter of exposure to PM 2.5 (<54.5 μg/m 3), participants in the highest quarter (>78.2 μg/m 3) had an increased risk of incident stroke (hazard ratio 1.53, 95% confidence interval 1.34 to 1.74), ischemic stroke (1.82, 1.55 to 2.14), and hemorrhagic stroke (1.50, 1.16 to 1.93). For each increase of 10 μg/m 3 in PM 2.5 concentration, the increased risks of incident stroke, ischemic stroke, and hemorrhagic stroke were 13% (1.13, 1.09 to 1.17), 20% (1.20, 1.15 to 1.25), and 12% (1.12, 1.05 to 1.20), respectively. Almost linear exposure-response relations between long term exposure to PM 2.5 and incident stroke, overall and by its subtypes, were observed. Conclusions: This study provides evidence from China that long term exposure to ambient PM 2.5 at relatively high concentrations is positively associated with incident stroke and its major subtypes. These findings are meaningful for both environmental and health policy development related to air pollution and stroke prevention, not only in China, but also in other low and middle income countries.