title: Apolipoprotein E gene polymorphism and the risk of intracerebral hemorrhage: a meta-analysis of epidemiologic studies.
abstract: BACKGROUND
  Studies investigating the association between the apolipoprotein E (APOE) gene polymorphism and the risk of intracerebral hemorrhage (ICH) have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship.
  
  
  METHODS
  Published literature from the National Library of Medline and Embase databases were retrieved. Odds ratio (OR) and 95% confidence interval (CI) were calculated in fixed- or random-effects models when appropriate. Subgroup analyses were performed by race.
  
  
  RESULTS
  This meta-analysis included 11 case-control studies, which included 1,238 ICH cases and 3,575 controls. The combined results based on all studies showed that ICH cases had a significantly higher frequency of APOE ϵ4 allele (OR= 1.42, 95% CI= 1.21,1.67, P<0.001). In the subgroup analysis by race, we also found that ICH cases had a significantly higher frequency of APOE ϵ4 allele in Asians (OR= 1.52, 95% CI= 1.20,1.93, P<0.001) and in Caucasians (OR= 1.34, 95% CI= 1.07,1.66, P=0.009). There was no significant relationship between APOE ϵ2 allele and the risk of ICH.
  
  
  CONCLUSIONS
  Our meta-analysis suggested that APOE ϵ4 allele was associated with a higher risk of ICH.
authors.forename: Rongjun
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Third Hospital of Chinese PLA, 45 Dongfeng Road, Jin Tai District, Baoji 721004, Shanxi Province, China. xfwang13@hotmail.com.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.forename: Zongchun
authors.initials: Z
authors.lastname: Tang
authors.forename: Jianxin
authors.initials: J
authors.lastname: Liu
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Yang
authors.forename: Youbing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yijun
authors.initials: Y
authors.lastname: Wei
authors.forename: Wenyin
authors.initials: W
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Jialong
authors.initials: J
authors.lastname: Li
authors.forename: Bobo
authors.initials: B
authors.lastname: Chen
authors.forename: Kunhu
authors.initials: K
authors.lastname: Zhang
mesh_terms: D001057:Apolipoproteins E / Q000235:genetics*; D016022:Case-Control Studies; D002543:Cerebral Hemorrhage / Q000235:genetics*; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D011110:Polymorphism, Genetic; D020033:Protein Isoforms / Q000235:genetics; D012307:Risk Factors
chemical_list: D001057:Apolipoproteins E; D020033:Protein Isoforms