Association of the genetic variants of endothelial nitric oxide synthase gene with angiographically defined coronary artery disease and myocardial infarction in South Indian patients with type 2 diabetes mellitus

IntroductionThe polymorphic variants of endothelial nitric oxide synthase (eNOS) gene have been implicated in endothelial dysfunction and are highly relevant to macroangiopathies. We investigated the relationship between eNOS gene T-786C, G894T, intron 4a/b polymorphisms and coronary artery disease (CAD) in South Indian type 2 diabetic (T2DM) individuals.MethodsWe screened 283 T2DM patients, inclusive of 160 with angiographically defined CAD, 73 with myocardial infarction (MI), 89 without MI and 121 T2DM individuals with no evidence of CAD for eNOS gene polymorphisms.ResultsThere appeared to be a significant difference in the genotype and allele distribution of eNOS T-786C polymorphism between T2DM groups with and without CAD (p = 0.004), albeit no significant association with MI was observed. The frequencies of TC and CC genotypes and − 786C allele were considerably higher in patients with triple vessel disease (TVD) as compared to those without CAD (p = 0.003), thereby associating this polymorphism with severity of CAD. Genotype and allele distributions of G894T and intron 4a/b polymorphisms were not significantly different between T2DM subjects with and without CAD/MI. Significant linkage disequilibrium was observed between intron 4a/b and T-786C polymorphisms. Multiple logistic regression analysis revealed a significant and independent association of eNOS T-786C polymorphism and other putative risk factors with CAD/TVD in T2DM individuals.ConclusionsThese findings reveal a significant association between eNOS T-786C polymorphism, CAD/TVD and coincident putative risk factors in T2DM individuals in South Indian population.