The relationship between polymorphic variants of the endothelial NO-synthase gene and the course of diabetic nephropathy in patients with type 2 diabetes mellitus

Abstract

Objective — to identify a possible association between the endothelial nitric oxide synthase (eNOS) gene G894T (rs1799983) polymorphism and the markers of renal function and glucose metabolism in patients with type 2 diabetes mellitus (DM2) with diabetic nephropathy (DN).
 Materials and methods. Examinations 126 patients with diabetic nephropathy (DN). The control group included 20 healthy individuals. Patients with DM2 were divided into two groups depending on the eNOS rs1799983 gene polymorphism: group I — patients with DN and G/G genotype eNOS G894T gene (n=80); group II — patients with DN and G/T and T/T genotypes eNOS G894T gene (n=46). Genotyping of the of the eNOS rs1799983 gene polymorphism was performed by the Taq‑Man® Fast Universal PCR Master Mix (Applied Biosystems, USA) and TaqMan® SNP Assay (Applied Biosystems, USA).
 Results. It has been established that in patients with DN, the distribution of genotypes of the G894T polymorphism of the eNOS gene corresponded to the Hardy‑Weinberg equilibrium in all groups and does not differ significantly from European populations. In diabetic patients with DN the 3 times higher total frequency of G/T and T/T genotypes eNOS G894T gene was established when compared to the control group. These findings prove the undoubted influence of the T allele on the development of DN in this group of patients. DN patients with genotypes G/T and T/T had significantly higher blood glucose and HOMA index (p <0.05) than G homozygotes (genotype G/G). Patients with DN and G/G genotype eNOS G894T gene had better glomerular filtration rate and lower albuminuria compared to patients with G/T and T/T genotypes (p <0.05).
 Conclusions. The establishing of association of eNOS gene polymorphism with the disease and further assessment of individual genetic risk is important for the development of a differentiated approach to the prevention and treatment of DN in patients with DM2 depending on the hereditary predisposition of an individual patient. Therefore, currently one of the most progressive approaches is to develop a strategy for early diagnosis, prognosis and preventive therapy of the disease using genetic markers.