In contrast, the 2-h insulin [30.08 (17.83–63.43) vs. 18.71 (11.37–28.20) mmol/L, P = 0.015], fasting C-peptide (2.40 ± 0.87 vs. 1.94 ± 0.90 nmol/mL, P = 0.042), and 2-h C-peptide concentrations (6.00 ± 3.00 vs. 3.82 ± 1.73 nmol/mL, P = 0.001) were higher in the T2DM group than in the DR group. This evidence concerns the gene INS and type 2 diabetes mellitus.