The association between endothelial nitric oxide synthase gene G894T polymorphism and hypertension in Han Chinese: a case-control study and an updated meta-analysis.

UNLABELLED: Abstract Background: The G894T (rs1799983) polymorphism in endothelial nitric oxide synthase (eNOS/NOS3) gene has been implicated in susceptibility to essential hypertension (EH) in some studies, but no clear consensus has been reached in the Chinese population. AIMS: This study aimed to investigate the association of the G894T polymorphism and EH in Han Chinese. SUBJECTS AND METHODS: First, a case-control study was performed involving 1525 subjects in northern Han Chinese to study the association between G894T variants and EH and then a meta-analysis was conducted of all available studies in Han Chinese. A total of 25 studies comprising 13,443 subjects were finally included in this meta-analysis. RESULTS: The present case-control study failed to show significant association of G894T variant with EH in northern Han Chinese. The subsequent meta-analysis showed that this polymorphism might be associated with EH in Han Chinese (p < 0.001, OR = 1.32), especially in southern Han Chinese (p < 0.001, OR = 1.59), but not in northern Han Chinese (p = 0.12, OR = 1.16). The meta-regression analysis suggested that the geographic difference of subjects was related to heterogeneity (p = 0.029). CONCLUSIONS: The relationship between the G894T polymorphism and hypertension in Han Chinese may be attributed to the difference in geographic background of subjects. It is necessary to carry out further research with a large sample size and focusing on gene-environment interactions.