Association of Exposure to particular matter and Carotid Intima-Media Thickness: A Systematic Review and Meta-Analysis.
BACKGROUND
Long time exposure to particular matter has been linked to myocardial infarction, stroke and blood pressure, but its association with atherosclerosis is not clear. This meta-analysis was aimed at assessing whether PM₂.₅ and PM₁₀ have an effect on subclinical atherosclerosis measured by carotid intima-media thickness (CIMT).


METHODS
Pubmed, Ovid Medline, Embase and NICK between 1948 and 31 March 2015 were searched by combining the keywords about exposure to the outcome related words. The random-effects model was applied in computing the change of CIMT and their corresponding 95% confidence interval (95% CI). The effect of potential confounding factors was assessed by stratified analysis and the impact of traffic proximity was also estimated.


RESULTS
Among 56 identified studies, 11 articles satisfied the inclusion criteria. In overall analysis increments of 10 μg/m³ in PM₂.₅ and PM₁₀ were associated with an increase of CIMT (16.79 μm; 95% CI, 4.95-28.63 μm and 4.13 μm; 95% CI, -5.79-14.04 μm, respectively). RESULTS shown in subgroup analysis had reference value for comparing with those of the overall analysis. The impact of traffic proximity on CIMT was uncertain.


CONCLUSIONS
Exposure to PM₂.₅ had a significant association with CIMT and for women the effect may be more obvious.
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. lxlryyc@sina.com.
Xiaole
X
Liu
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. lianhui1988@163.com.
Hui
H
Lian
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. yanping.ruan@163.com.
Yanping
Y
Ruan
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. 18911122174@163.com.
Ruijuan
R
Liang
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. zhaoxy0909@sina.com.
Xiaoyi
X
Zhao
Leeds Institute of Cardiovascular & Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK. medmnr@leeds.ac.uk.
Michael
M
Routledge
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China. Fan@pumch.cn.
Zhongjie
Z
Fan
D000393:Air Pollutants / Q000633:toxicity*; D050197:Atherosclerosis / Q000453:epidemiology*; D059168:Carotid Intima-Media Thickness; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D052638:Particulate Matter / Q000633:toxicity*
D000393:Air Pollutants; D052638:Particulate Matter
PM10; PM2.5; air pollution; carotid intima-media thickness; meta-analysis; subclinical atherosclerosis