SOD2 and type 2 diabetes mellitus: T2DM: type 2 diabetes mellitus; SGLT2i: sodium-glucose cotransporter 2 inhibitors; SOD: superoxide dismutase; MnSOD: manganese superoxide dismutase; TAC: total antioxidant capacity; R-SH: sulfhydryl groups; CAT: catalase; n: number of patients.