title: Glutathione S-transferase M1 polymorphism and endometriosis susceptibility: a meta-analysis.
abstract: BACKGROUND
  Many studies have investigated the association between glutathione S-transferase M1 (GSTM1) null genotype and the risk of endometriosis. However, the effect of the GSTM1 null genotype on endometriosis is still unclear because of apparent inconsistencies among those studies. A meta-analysis was performed to characterize the relationship more accurately. PubMed, Embase, and Web of Science were searched.
  
  
  OBJECTIVE
  To derive a more precise estimation of the relationship, a meta-analysis was performed.
  
  
  METHODS
  We estimated the summary odds ratio (OR) with a 95% confidence interval (95% CI) to assess the association. Up to 24 case-control studies with 2,684 endometriosis cases and 3,119 control cases were included into this meta-analysis.
  
  
  RESULTS
  Meta-analysis of the 24 studies showed that GSTM1 null genotype was associated with the risk of endometriosis (random effects OR=1.66, 95% CI 1.23 to 2.24). In the subgroup analysis by ethnicity, increased risks were found for both Caucasians (OR=1.26, 95% CI 1.04-1.51) and Asians (OR=1.28, 95% CI 1.06-1.55). No evidence of publication bias was observed.
  
  
  CONCLUSIONS
  In conclusion, this meta-analysis suggests that the GSTM1 null genotype increases the overall risk of endometriosis.
authors.affiliation: Department of Gynaecology, Shi Jia Zhuang the Third Hospital, Shi Jia Zhuang 050011, China.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.affiliation: Reproductive Medicine Center, Zhongnan Hospital, Wuhan University, 169, Donghu Road, Hubei Province, Wuhan 430071, China. Electronic address: yuanzhenzhang62@126.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004715:Endometriosis / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D011110:Polymorphism, Genetic; D055815:Young Adult
chemical_list: D005982:Glutathione Transferase
keywords: Endometriosis; Endométriose; GSTM1; Meta-analysis; Méta-analyse; Polymorphism; Polymorphisme