title: Null genotypes of GSTM1 and GSTT1 contribute to male factor infertility risk: a meta-analysis.
abstract: OBJECTIVE
  To study the null of GSTM1, GSTT1, or GSTT1-GSTM1 and the risk of male factor infertility.
  
  
  METHODS
  Meta-analysis using electronic databases (Pubmed, Medline, Embase, and China National Knowledge Infrastructure) up to August 22, 2011.
  
  
  METHODS
  The strength of the relationship between the null of GSTM1, GSTT1, and GSTT1-GSTM1 and the risk of male factor infertility was assessed by odds ratios (ORs). A total of 16 studies were identified in this meta-analysis. Among the 16 studies, 15 studies reported GSTM1null, 10 reported GSTT1, and five reported GSTM1-GSTT1.
  
  
  METHODS
  Male infertility patients and a fertile control group.
  
  
  METHODS
  Meta-analyses by means of random-effects models and fixed-effects models.
  
  
  METHODS
  Ratio of male factor infertility.
  
  
  RESULTS
  The studies provided overall OR estimates for GSTM1, GSTT1, and GSTM1-GSTT1, leading to a pooled OR of 1.41 (95% confidence interval [CI], 1.10-1.81), 1.15 (95% CI, 0.95-1.39), and 2.99 (95% CI, 2.14-4.18), respectively.
  
  
  CONCLUSIONS
  There was evidence that the null of GSTM1 and GSTM1-GSTM1 increased the risk of male factor infertility, but the null genotype of GSTT1 was not associated with an increased infertility risk. We still need further multicenter and better controlled studies to confirm these findings.
authors.affiliation: Department of Hepatobilliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Kan
authors.forename: Fang-Lei
authors.initials: FL
authors.lastname: Wu
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Guo
authors.forename: Yong-Zhong
authors.initials: YZ
authors.lastname: Wang
authors.forename: Jing-Ping
authors.initials: JP
authors.lastname: Li
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Huang
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Li
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Liu
mesh_terms: D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007248:Infertility, Male / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1