Association of manganese superoxide dismutase Ala16Val gene polymorphism with diabetic retinopathy risk in type 2 diabetes: A systematic review and meta-analysis

Background: Diabetic retinopathy (DR) is renowned as a prominent cause of visual impairment worldwide. The association between manganese superoxide dismutase (MnSOD) gene, Ala16Val (rs4880), and DR susceptibility in people with type 2 diabetes mellitus (T2DM) remains contentious. Objective: This meta-analysis aims to evaluate risk of DR in T2DM patients with MnSOD Ala16Val polymorphism. Methods: A literature search was conducted using MEDLINE, Scopus, Web of Science, ScienceDirect, EMBASE, and grey literature to identify potential studies assessing the link between MnSOD polymorphism and DR risk among T2DM patients. The data was further analyzed in fixed/random effect models using RevMan 5.3 under five genetic models. Results: Six studies comprising 2,132 subjects from four distinct ethnicities were included. The present study revealed that MnSOD gene polymorphism was associated with a significantly increasing DR risk in T2DM patients under the co-dominant model (VV vs. AA) (OR 1.87 1.42, 2.46, p<0.0001) and dominant model (VV+AV vs. AA) (OR 1.85 1.02, 3.33, p=0.0400). Conclusions: T2DM individuals with rs4880 VV alleles are more susceptible to DR development, making them as a potential marker for heightened DR susceptibility in T2DM patients, laying the foundation for a gene panel to assess their susceptibility to develop DR. © 2024 Elsevier B.V., All rights reserved.