Association study between superoxide Dismutases gene polymorphisms and development of diabetic retinopathy and cataract in Iranian patients with type two diabetes mellitus.

PURPOSE: Reactive oxygen species (ROS) plays pathological roles on development of diabetic retinopathy (DR) and cataract. Superoxide dismutases (SODs) are a set of enzymes to eliminate ROS and cell protection. Based on the diminished activities of SOD1 during DR and cataract, the polymorphisms within SOD1 gene may be associated with these disorders. This study assessed the relationship between SOD1 -251A/G (rs2070424) and SOD1 + 35A/C (rs2234694) gene polymorphisms and DR and cataract in Iranian patients with type 2 diabetes mellitus (T2DM).
METHODS: Totally, 141 cases (73 patients with cataract and 68 with DR) with a at least five years history of T2DM and 119 age/gender matched persons without history of DM were included in the case and control groups, respectively. Genomic DNA was extracted from peripheral venous blood cells and genotyping of 251A/G and + 35A/C polymorphisms was done using PCR-RFLP technique. Statistical analysis was done using SPSS version 22.
RESULTS: Results showed SOD1 -251A/G and + 35A/C genotype frequency were significantly associated (1.9 folds) with cataract (P = 0.045, OR = 0.524, 95% CI = 0.277-0.991 and P = 0.037, OR = 0.505, 95% CI = 0.265-.0965, respectively). Instead, no significant differences found between SOD -251A/G (P = 0.053, OR = 0.52, 95% CI = 0.276-1.014) and + 35A/C (P = 0.073, OR = 0.547, 95% CI = 0.281-1.063) polymorphisms and DR. Multivariate Logistic Regression model showed significant relationship between BMI, HDL and TC levels and independent predictors of T2DM (P < 0.05).
CONCLUSIONS: Based on the results, there was significant association between SOD1 gene polymorphisms and cataract in patients with T2DM. Therefore, SOD1 gene polymorphisms might be a potential marker for increased risk of cataract in patients with T2DM. © Springer Nature Switzerland AG 2021.