DM-without-metformin group had a significantly smaller BMI and less insulin use than DM-with-metformin group (mean [SD] BMI: DM-without-metformin group; 31.9 [9.4] vs DM-with-metformin group; 34.0 [9.2], t-test p = 0.01) (rate of insulin user: DM-without-metformin group; 45.0% vs DM-with-metformin group; 85.2%, chi-square test p < 0.001) (Table 1). This evidence concerns the gene INS and diabetes mellitus.