Association between endothelial NO synthase polymorphism (rs3918226) and arterial properties

BackgroundRecently, rs3918226 polymorphism in the promoter region of endothelial NO synthase (eNOS) was strongly associated with arterial hypertension in a large genome-wide association study. We investigated whether this polymorphism was associated with arterial phenotypes in a Czech general population.MethodsIn a pilot study, we genotyped 101 untreated subjects (mean age, 54.0 years). Arterial properties were measured using SphygmoCor. We used robust multivariate analysis to assess whether rs3918226 was associated with peripheral or central blood pressure, carotid-femoral pulse wave velocity (PWV) and aortic augmentation index (AIx). As independent covariates we considered sex, age, MAP, heart rate and smoking.ResultsFrequencies of rs3918226 genotypes were CC 85.2%, CT 14.8%, and TT 0%. Current smokers carrying mutated T allele had marginally higher PWV (10.0 ± 0.8 vs. 8.7 ± 0.4 m/s; P = 0.051) and significantly higher AIx (172.2 ± 6.8 vs. 153.2 ± 3.8%; P = 0.024) compared to CC homozygotes. In non-smokers we did not find any association between rs3918226 and arterial properties (P ≥ 0.62). Moreover, we did not observe any association between either peripheral or central blood pressure and the polymorphism under study (P ≥ 0.58).ConclusionsThis is the first study to explore the association of rs3918226 polymorphism in eNOS gene with arterial properties. Mutated T allele was associated with higher PWV and AIx in smokers. We hypothesize that genetic modulation of intermediate arterial phenotypes might lead to higher blood pressure. As the prevalence of T allele is low, further study with a sufficient number of subjects is warranted.