DPP-4i, dipeptidyl peptidase-4 inhibitor; FM, family medicine; GLP-1 RA, glucagon-like peptide-1 receptor agonist; GP, general physician; PHCC, primary health care center; p, probability; SGLT-2i, sodium-glucose co-transporter 2 inhibitor; T2DM, type 2 diabetes mellitus; X2, chi-square. This evidence concerns the gene DPP4 and diabetes mellitus.