title: Alcohol intake and risk of stroke: a dose-response meta-analysis of prospective studies.
abstract: BACKGROUND
  Alcohol intake is inconsistently associated with the risk of stroke morbidity and mortality. The purpose of this study was to summarize the evidence regarding this relationship by using a dose-response meta-analytic approach.
  
  
  METHODS
  We performed electronic searches of PubMed, EMBASE, and the Cochrane Library to identify relevant prospective studies. Only prospective studies that reported effect estimates with 95% confidence intervals (CIs) of stroke morbidity and mortality for more than 2 categories of alcohol intake were included.
  
  
  RESULTS
  We included 27 prospective studies reporting data on 1,425,513 individuals. Low alcohol intake was associated with a reduced risk of total stroke (risk ratio [RR], 0.85; 95% CI: 0.75-0.95; P=0.005), ischemic stroke (RR, 0.81; 95% CI: 0.74-0.90; P<0.001), and stroke mortality (RR, 0.67; 95% CI: 0.53-0.85; P=0.001), but it had no significant effect on hemorrhagic stroke. Moderate alcohol intake had little or no effect on the risks of total stroke, hemorrhagic stroke, ischemic stroke, and stroke mortality. Heavy alcohol intake was associated with an increased risk of total stroke (RR, 1.20; 95% CI: 1.01-1.43; P=0.034), but it had no significant effect on hemorrhagic stroke, ischemic stroke, and stroke mortality.
  
  
  CONCLUSIONS
  Low alcohol intake is associated with a reduced risk of stroke morbidity and mortality, whereas heavy alcohol intake is associated with an increased risk of total stroke. The association between alcohol intake and stroke morbidity and mortality is J-shaped.
authors.affiliation: Department of Neurosurgery, Shanghai Seventh People's Hospital, Shanghai 200137, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Health Statistics, Second Military Medical University, Shanghai 200433, China.
authors.forename: Ying-Yi
authors.initials: YY
authors.lastname: Qin
authors.affiliation: Department of Health Statistics, Second Military Medical University, Shanghai 200433, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Politics, Second Military Medical University, Shanghai 200433, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Neurosurgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
authors.forename: Xian-Zhen
authors.initials: XZ
authors.lastname: Chen
authors.affiliation: Department of Neurology, Shanghai Seventh People's Hospital, Shanghai 200137, China.
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Xu
authors.affiliation: Department of VIP Special Clinic, Shanghai Seventh People's Hospital, Shanghai 200137, China.
authors.forename: Pei-Juan
authors.initials: PJ
authors.lastname: Mao
authors.affiliation: Department of Health Statistics, Second Military Medical University, Shanghai 200433, China. Electronic address: hejia63@yeah.net.
authors.forename: Jia
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Rehabilitation Institute, Shanghai Seventh People's Hospital, Shanghai 200137, China. Electronic address: zhou_ly@126.com.
authors.forename: Yu-Hao
authors.initials: YH
authors.lastname: Zhou
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology* / Q000639:trends; D000434:Alcoholic Beverages / Q000009:adverse effects; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage; D006801:Humans; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*
chemical_list: D000431:Ethanol
keywords: Alcohol intake; Dose–response; Meta-analysis; Stroke