Endothelial nitric oxide synthase gene G894T polymorphism and risk assessment for pregnancy-induced hypertension: evidence from 11 700 subjects.

Recent studies have reported the association between endothelial nitric oxide synthase (eNOS) gene G894T polymorphism and pregnancy-induced hypertension (PIH). However, the results have been inconsistent. We conducted a comprehensive meta-analysis to explore this association. A total of 36 case-control studies involving 4028 PIH cases and 7672 controls were ultimately included. In the overall analysis, no association was identified between eNOS gene G894T polymorphism and PIH risk in any of the genetic models. In the subgroup analysis, the results showed that T-allele carriers had a higher risk of PIH than those with the G allele in Asians (G vs. T: odds ratio (OR)=0.76, 95% confidence interval (CI)=0.63-0.91, P=0.002; GT+TT vs. GG: OR=1.32, 95% CI=1.09-1.59, P=0.004; TT vs. GT+GG: OR=1.96, 95% CI=1.26-3.06, P=0.003; TT vs. GG: OR=1.99, 95% CI=1.27-3.11, P=0.003; GT vs. GG: OR=1.23, 95% CI=1.05-1.43, P=0.009). For Latin American and African populations, the association between G894T polymorphism and susceptibility to PIH was only observed in the dominant model. However, no association was observed in Europeans and Americans. Therefore, eNOS gene G894T polymorphism was related to PIH risk, especially for Asians.