title: Glutathione S-transferase P1 Ile105Val Polymorphism and Male Infertility Risk: An Updated Meta-analysis.
abstract: BACKGROUND
  Several studies concerning the association between glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism and male infertility risk have reported controversial findings. The present study was aimed to explore this association using a meta-analysis.
  
  
  METHODS
  The PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Wanfang databases were searched. Odds ratios (OR s) with 95% confidence intervals (CI s) were calculated to estimate the strength of the association.
  
  
  RESULTS
  A total of 3282 cases and 3268 controls in nine case-control studies were included. There was no significant association between GSTP1 Ile105Val polymorphism and male infertility in the overall population, but significant associations were found under the dominant (OR = 1.23, 95% CI = 1.04-1.46, I2 = 32.2%) and heterozygote (OR = 1.29, 95% CI = 1.08-1.53, I2 = 26.8%) models after excluding studies for which the data did not satisfy Hardy-Weinberg equilibrium (HWE). Similarly, subgroup analyses revealed no significant association in Asians or Chinese population although a significant association was apparent among Chinese population in studies with HWE under the heterozygote model (OR = 1.25, 95% CI = 1.03-1.52, I2 = 44.1%). Significant heterogeneity could be observed in some genetic models, but this heterogeneity was not significant when stratified by HWE. No evidence for publication bias was found.
  
  
  CONCLUSIONS
  The GSTP1 Ile105Val polymorphism might not be associated with male infertility risk, and thus additional well-designed studies with larger sample size are warranted.
authors.affiliation: Department of Obstetrics and Gynaecology, Reproductive Medicine Center, The First People's Hospital of Foshan, Foshan, Guangdong 528000, China.
authors.forename: Xue-Kun
authors.initials: XK
authors.lastname: Huang
authors.affiliation: Department of Obstetrics and Gynaecology, Reproductive Medicine Center, The First People's Hospital of Foshan, Foshan, Guangdong 528000, China.
authors.forename: Yong-Han
authors.initials: YH
authors.lastname: Huang
authors.affiliation: Department of Obstetrics and Gynaecology, Reproductive Medicine Center, The First People's Hospital of Foshan, Foshan, Guangdong 528000, China.
authors.forename: Juan-Hua
authors.initials: JH
authors.lastname: Huang
authors.affiliation: Department of Dermatology, Institute of Dermatology, Guangzhou Medical University, Guangzhou, Guangdong 510095; Department of Dermatology, Institute of Dermatology, Guangzhou Institute of Dermatology, Guangzhou, Guangdong 510095, China.
authors.forename: Jing-Yao
authors.initials: JY
authors.lastname: Liang
mesh_terms: D044466:Asian People; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D051549:Glutathione S-Transferase pi / Q000235:genetics*; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D051549:Glutathione S-Transferase pi