To determine the effect of different antidiabetic drugs on the outcomes of patients with COVID-19 and T2DM, we used the data of patients with COVID-19 from December 2019 to August 2021 in Hubei Province, China, to compare common antidiabetic drugs, such as insulin, metformin, alpha-glycosidase inhibitors, sulfonylureas, glinides, and DPP4 inhibitors. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.