NOS3 polymorphisms are associated with arterial stiffness in children with type 1 diabetes

OBJECTIVE - Type I diabetes is associated with endothelial dysfunction, arterial stiffness, and an increased risk of cardiovascular disease (CVD) events. We previously demonstrated increased arterial stiffness in children with type I diabetes compared with control subjects. However, traditional CVD risk factors did not explain the difference in arterial stiffness. Furthermore, children with type I diabetes displayed notable within-group variation in arterial stiffness. We hypothesized that polymorphisms in the NOS3 gene may be associated With the differences seen in arterial stiffness within the population of children with type I diabetes. RESEARCH DESIGN AND METHODS - Thirty-six consecutively enrolled subjects aged 10-21 years with type I diabetes were studied. Subjects underwent radial tonometry in a fasting state. A corrected augmentation index (AI(75)) was the primary measure of arterial stiffness. Genotypes were determined for the NOS3 - 786T -> C and Glu298 -> Asp polymorphisms by pyrosequencing. AI(75) values by genotype groups were compared by ANOVA and multivariate analysis. RESULTS - Median (interquartile range) AI(75) values for -786TT and -786C carriers were -3.5 (-8.8 to 2.3) and 11.0 (6.0 to 14.4), respectively (P = 0.01); Al-75 values for Glu298GIu patients and Asp298 carriers were 2.3 (-4.0 to 13.0) and 7.3 (-2.0 to 11.5), respectively (P = 0.59). In univariate analysis, age, sex, BMI percentile, and -786T -> C genotype were significantly associated with AI(75). The multivariate model, which included these four variables, was significantly associated with AI(75) (P = 0.002, R-2 = 0,40). CONCLUSIONS - This is the first reported association between -786T -> C and arterial stiffness in type I diabetes. Larger studies are needed to confirm this observation for potential translation to risk assessment.