Features of clinical and diagnostic parameters of distal symmetrical polyneuropathy in patients with type 2 diabetes mellitus in the dynamics of treatment depending on the endothelial nitric oxide synthase gene G894T polymorphism

Background. The purpose of the study is to determine the dynamics of clinical and laboratory characteristics and functional state of peripheral nerves in patients with type 2 diabetes mellitus (DM) complicated by distal symmetrical polyneuropathy (DSPN) depending on the frequency distribution of the G894T genotypes of endothelial NO-synthase (eNOS) gene polymorphism during the recommended therapy. Mate­rials and methods. 110 patients were examined, they were divided into groups: with initial manifestations of DSPN — 32 (29.1 %), with moderate course — 58 (52.7 %) and with severe course — 20 (18.2 %). Patients received L-arginine preparation during basic treatment. All patients were neurologically examined using Neuropathic Symptomatic Score, Neuropathic Dysfunctional Score, electroneuromyographic testing of the peripheral nerves of the lower extremities; parameters of carbohydrate metabolism, pro- and antioxidant defense, functional state of the endothelium were evaluated. Results. In patients with DSPN and type 2 DM, homozygotes for the minor T allele of the eNOS gene G894T polymorphism, the likelihood of developing severe complications of diabetic polyneuropathy increases: the odds ratio was 2.91 (95 % confidence interval 1.19–7.14; p < 0.05). In patients with GT and GG genotypes, the highest efficacy of the recommended therapy is determined, in contrast to patients with homozygous TT genotype, whose dynamics of clinical, laboratory and functional indicators was significantly lower. Conclusions. Homozygotes for the minor T allele of the eNOS gene G894T polymorphism have an increase in the incidence and the severity of DSPN course on the background of type 2 DM, and also a less stable effect from the treatment of this complication