In this cohort study, patients with type 2 diabetes mellitus and eGFR < 30 mL/min per 1.73 m2 with a first prescription for GLP-1RAs or dipeptidyl peptidase 4 inhibitors (DPP-4is) from 2012 to 2021 (n = 125,392) were enrolled. This evidence concerns the gene DPP4 and diabetes mellitus.