Usual diabetes treatment received concomitantly by the participants was diet only (n = 9) or diet plus oral agents (metformin, n = 48; sulfonylurea, n = 43; dipeptidyl peptidase-4 inhibitors, n = 11; glucagon-like peptide-1 agonist, n = 1; acarbose, n = 4; metformin + pioglitazone, n = 1). This evidence concerns the gene DPP4 and diabetes mellitus.