Relationship Between the Single Nucleotide Polymorphism A35C in the Cu/Zn-Superoxide Dismutase-1 Gene and Glycemic Control in Individuals with Type 2 Diabetes Mellitus

Hyperglycemia in type 2 diabetes mellitus (T2DM) increases oxidative stress. Furthermore, the presence of the single nucleotide polymorphism A35C (SNP A35C) in Cu/Zn-superoxide dismutase1 (SOD1) gene is closely related to this increase in oxidative stress and the development and progression of T2DM and its complications. This study aimed to evaluate the association between SNP A35C (rs2234694) genotypes and glycemic control in T2DM individuals. A total of 110 individuals were evaluated for anthropometric parameters, body composition, glycemic metabolism markers (fasting serum glucose, %HbA1c, insulin, C-peptide, and HOMA-IR, -%B, -%S), and SOD activity. Individuals were grouped according to SNP A35C genotypes. Variables of interest were assessed according to groups. The T-test for independent samples or the Mann-Whitney U test was used to analyze the differences in continuous variables between groups, and the chi-square test was performed for categorical variables. A binary logistic regression model was constructed, with p < 0.05 considered significant. Overweight was found in 81.8% of individuals with T2DM. Individuals with the AC genotype for SNP A35C had higher levels of fasting serum glucose (p = 0.018) and lower values of HOMA-%B (p = 0.044). The presence of the variant allele was positively associated with higher values of fasting serum glucose (OR: 11.340; 95%IC 1.173-109.649; p = 0.036) and HOMA-IR (OR: 9.987; 95%IC 1.127-88.506; p = 0.039). Individuals with the AC genotype of SNP A35C had poorer glycemic control than individuals with the AA genotype, and the presence of the variant allele was associated with poor glycemic control in T2DM individuals.