GSTM1 and GSTT1 polymorphisms and risk of preeclampsia: a system review and meta-analysis

Objective: Oxidative stress is thought to play an important role in the pathophysiology of pre-eclampsia. The glutathione S-transferases (GST) are a group of enzymes that protect cells from oxidative stress. Published data on the association between the GSTT1 and GSTM1 polymorphisms and pre-eclampsia risk are controversial. A meta-analysis was performed to assess whether the polymorphisms of GSTT1 and GSTM1 are associated with pre-eclampsia risk. Methods: Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases were searched to identify eligible studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for GSTT1 and GSTM1 polymorphisms and pre-eclampsia were appropriately derived from fixed-effects or random effects models. Results: A total of 11 studies were enrolled in this meta-analysis. The pooled analyses revealed that polymorphisms of GSTT1 and GSTM1 was not associated with pre-eclampsia risk. Heterogeneity among studies was founded in GSTT1 polymorphism. Galbraith plot analyses were performed to assess the source of heterogeneity and one study was found to be contributor of heterogeneity. The heterogeneity decreased significantly after excluding that study. Conclusion: Present meta-analysis reveals that GSTT1 and GSTM1 polymorphisms may be not correlated to pre-eclampsia risk.