Influence of nitric oxide synthase gene polymorphism (G894T) on carotid artery intima-media thickness in adults: the Bogalusa Heart Study

Nitric oxide generated by the vascular endothelial nitric oxide synthase (eNOS) plays an important role in the regulation of vascular structure/function and blood pressure. However, information is scant regarding the influence of G894T polymorphism of the eNOS gene on arterial wall thickness in asymptomatic young adults. This aspect was examined for G894T polymorphism in 661 White and Black subjects, aged 25 to 43 years (73.2% White; 39.5% male). Arterial vascular changes were assessed by common carotid intima-media thickness (IMT) using B-mode ultrasonography. The variant T allele frequency of G894T was significantly higher in Whites compared with Blacks (0.339 vs. 0.102; P < .0001). In bivariate analysis, adjusted for gender, age, mean arterial blood pressure, and/or race, carotid IMT was marginally lower in carriers vs. non-carriers of T allele in Whites (P = .07), but significantly lower for the total number of subjects (P = .04). In multivariable regression analysis, adjusted for gender, age, mean arterial pressure, body mass index (BMI), low-density lipoprotein cholesterol, triglycerides/high-density lipoprotein cholesterol ratio, homeostasis model assessment of insulin resistance, smoking, and race (in the total sample), the variant allele was independently associated with lower carotid IMT in both the White subjects (P = .04), and total sample (P = .03). These results suggest that the allelic variation of G894T polymorphism of the eNOS gene beneficially influences vascular changes as measured by carotid IMT in asymptomatic young adults.