Upon dividing by groups, in T2D, 39% of C-peptide concentration was influenced by WC (ß = 0.496), sex (ß = 0.307), and insulin use (ß = −0.288), while in T1D, 19% of C-peptide concentration was influenced by BMI (ß = 0.482). This evidence concerns the gene INS and type 2 diabetes mellitus.