T-786C polymorphism in the endothelial nitric oxide synthase gene is associated with increased risk of coronary artery disease in a Chinese population

Abstract

Background/aims: Many investigations have revealed that genetic influences can have an important impact on the incidence and progression of coronary artery disease (CAD). The aim of this research was to discover whether the T-786C polymorphism in the promoter 5'-flanking region of the gene for endothelial nitric oxide synthase (eNOS) is associated with CAD.

Methods: 622 Chinese Han subjects were enrolled in this case-control study. 312 had CAD confirmed by coronary angiography and 310 were healthy controls. Total genomic DNA was extracted from whole blood and genotype at position -786 of the eNOS gene determined by polymerase chain reaction-restriction fragment length polymorphism.

Results: The allelic frequencies were in Hardy-Weinberg equilibrium. The minor allele frequency of the T-786C polymorphism was higher in the CAD group than in controls: after adjustment for age, sex, body mass index, smoking status, plasma glucose and presence of hypertension, the odds ratio for the risk of CAD in T-786C allele carriers was 1.739 (1.215-2.490) in comparison to individuals without the minor allele. In a stratified analysis, the association between T-786C genotype and CAD risk was greater in men, individuals > or =60 years of age, smokers, hypertensives and subjects with a body mass index > or =25. The T-786C polymorphism was associated with higher total and low-density lipoprotein cholesterol levels in control but not in CAD subjects.

Conclusions: The T-786C polymorphism of the eNOS gene appears to be an independent risk factor for CAD in Chinese Hans. This finding requires confirmation in prospective studies and in studies of other populations.