DPP4 and diabetes mellitus: Although metformin and other interventions such as acarbose, sulfonylurea, thiazolidinedione, dipeptidyl peptidase 4 (DPP4) inhibitor, etc. are currently used to treat type 2 diabetes mellitus (T2DM), many patients with T2DM progress to develop DCM, and this has been associated with diabetes-related deaths globally.