Short-term Effects Of Particulate Matter On Stroke Attack:Meta-regression And Meta-analyses

Objective:To assess the relationship between particulate matter and stroke subtypes attack.Methods:Meta-analyses, meta-regression and subgroup analyses were conducted to investigate the association between short-term effects of exposure to particulate matter and the morbidity of different stroke subtypes from a number of epidemiologic studies (from1997to2012).Results:Nineteen articles were identified. Odds ratio (OR) of stroke attack associated with particular matter ("thoracic particles"[PM10]<10um in aerodynamic diameter,"fine particles"[PM2.5]<2.5μm in aerodynamic diameter) increment of10μg/m3was as effect size. PM10exposure was related to an increase in risk of stroke attack (OR per10μg/m3=1.004,95%CI:1.001-1.008) and PM2.5exposure was not significantly associated with stroke attack (OR per10μg/m3=0.999,95%CI (Confidence interval):0.994-1.003). But when focused on stroke subtypes, PM2.5(OR per10μg/m3=1.025;95%CI,1.001-1.049) and PM10(OR per10μg/m3=1.013;95%CI,1.001-1.025) exposure were statistically significantly associated with an increased risk of ischemic stroke attack, while PM2.5(all the studies showed no significant association) and PM10 (OR per10μg/m3=1.007;95%CI,0.992-1.022) exposure were not associated with an increased risk of hemorrhagic stroke attack. Meta-regression found study design and area were two effective covariates.Conclusion:PM2.5and PM10had different effects on different stroke subtypes. In the future, it’s worthwhile to study the effects of PM to ischemic stroke and hemorrhagic stroke, respectively.