Genetic polymorphisms (Pro197Leu of Gpx1, +35A/C of SOD1, −262C/T of CAT), the level of antioxidant proteins (GPx1, SOD1, CAT) and the risk of distal symmetric polyneuropathy in Polish patients with type 2 diabetes mellitus

Abstract

PurposeOxidative stress and impaired anti-oxidant defense are regarded as contributory factors for distal symmetric polyneuropathy (DSPN). The purpose of the study was to evaluate the plasma level of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) and the association between polymorphic variants in genes encoding for GPx1, SOD, CAT and the risk of DSPN in T2DM patients. Material/methodsWe included 401 individuals: 110 T2DM patients with DSPN, 135 T2DM patients without DSPN, and 156 control subjects with normoglycemia, and without DSPN. We employed RFPL-PCR to genotype polymorphic variants Pro197Leu of Gpx1, +35A/C of SOD1, −262C/T of CAT and ELISA tests to measure plasma level of SOD1, GPx1 and CAT. The odds ratios (ORs) and 95% confidence intervals (CIs) for each genotype and allele were calculated. ResultsThere was a significant decrease in the level of GPx1 (p<0.05), SOD1 (p<0.05) in T2DM patients with DSPN compared to healthy subjects. T2DM patients without DSPN showed a statistically lower serum level of GPX1 (p<0.05) than healthy subjects. SOD 1 and CAT levels were lower in T2DM patients with DSPN compared to T2DM patients without DSPN (p<0.05). The genetic analysis revealed the lack of association between examined polymorphic variants and the risk of DSPN. ConclusionsThe examined polymorphic variants are not associated with DSPN in Polish T2DM patients. The obtained results suggest that disturbances in antioxidant defense system may play significant role in the development and progression of DSPN.