Background The endothelial nitric oxide synthase (eNOS) G894T gene polymorphism has been suggested to be linked to the risk of essential hypertension (EH), however the results are still debatable.
Objective and Methods To assess the association between eNOS G894T gene polymorphism and EH, such electronic databases as Pubmed, Embase, Web of Science, China Biological Medicine Database (CBMD) and China National Knowledge Infrastructure (CNKI) were searched. The selection criteria were as follows: a) Evaluation of the association of eNOS G894T gene polymorphism and EH. b) EH diagnosis in compliance with EH diagnosis criteria of the World Health Organization (WHO) in 1999. c) The study results were in line with the Hardy-Weinberg equilibrium (HWE). In 23 separate studies with 11,248 subjects the relation between eNOS G894T gene polymorphism and EH was analyzed by current meta-analysis. Random effect model was used to calculate the pooled odds ratio (ORs) and its corresponding 95% confidence interval (95% CI).
Results In this eNOS G894T gene polymorphism and EH meta-analysis in the Chinese population, the distribution of T allele frequency was 0.154 for EH group and 0.128 for the control group. A significant association was found between G894T gene polymorphism and EH (p=0.0007). The pooled OR for the distribution frequency of T allele was 1.33 (95% CI:1.13-1.56, P_{heterogeneity} <0.00001). In the stratified analysis by ethnicity, there was a significant association in Han subgroup (p=0.005). The pooled OR for the distribution frequency of T allele was 1.31 (95% CI:1.09-1.59, P_{heterogeneity} <0.00001). No significant increased risk for EH was found in the non-Han subgroup (p=0.08).
Conclusion In the current meta-analysis, T allele of eNOS G894T gene was suggested to be related to the increased risk of EH in the Chinese population, particularly in those of Han ethnicity.