title: Genetic effects of common polymorphisms in estrogen receptor alpha gene on osteoarthritis: a meta-analysis.
abstract: OBJECTIVE
  The estrogen receptor alpha (ESR1) gene has been implicated in the etiology of osteoarthritis (OA). However, the results are conflicting. We assessed the association of three common ESR1 polymorphisms, rs2234693, rs9340799 and rs2228480, with OA in this meta-analysis.
  
  
  METHODS
  A comprehensive search was performed to identify related studies. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed or random effects model.
  
  
  RESULTS
  15 studies (7036 cases and 9669 controls) for rs2234693 polymorphism, 14 studies (3904 cases and 6991 controls) for rs9340799 and 3 studies (331 cases and 619 controls) for rs2228480 polymorphism were identified. The final results indicated that the G allele in ESR1 rs9340799 was associated with decreased OA risk (GG+GA vs. AA: OR=0.878, 95% CI=0.792-0.972, P=0.012; G vs. A: OR=0.902, 95% CI=0.836-0.975, P=0.009). The A allele in rs2228480 might be associated with increased OA risk. But no significant association of rs2234693 polymorphism with OA susceptibility was observed.
  
  
  CONCLUSIONS
  This meta-analysis indicates rs9340799 and rs2228480 rather than rs2234693 polymorphisms are associated with the incidence of OA. Some stable associations should be further confirmed in future.
authors.affiliation: Department of Bone and Joint, The First Hospital of Jilin University Changchun 130021, Jilin, China.
authors.forename: Hecheng
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Bone and Joint, The First Hospital of Jilin University Changchun 130021, Jilin, China.
authors.forename: Weiqian
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Bone and Joint, The First Hospital of Jilin University Changchun 130021, Jilin, China.
authors.forename: Xiaodi
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Bone and Joint, The First Hospital of Jilin University Changchun 130021, Jilin, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Bone and Joint, The First Hospital of Jilin University Changchun 130021, Jilin, China.
authors.forename: Yubao
authors.initials: Y
authors.lastname: Gong
keywords: Estrogen receptor alpha; meta-analysis; osteoarthritis; polymorphism