Null genotypes of GSTM1 and GSTT1 contribute to male factor infertility risk: a meta-analysis

Objective To study the null of GSTM1, GSTT1, or GSTT1-GSTM1 and the risk of male factor infertility. Design Meta-analysis using electronic databases (Pubmed, Medline, Embase, and China National Knowledge Infrastructure) up to August 22, 2011. Setting 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. Patient(s) Male infertility patients and a fertile control group. Intervention(s) Meta-analyses by means of random-effects models and fixed-effects models. Main Outcome Measure(s) Ratio of male factor infertility. Result(s) 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. Conclusion(s) 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.