DPP4 and diabetes mellitus: In the recently announced updated positional statement of the American Diabetes Association and the European Association for the Study of Diabetes (EASD) for management of hyperglycemia in type 2 diabetes, metformin was recommended as first-line therapy, and combined therapy of metformin and incretin-based therapy, such as GLP-1R agonists and DPP–4 inhibitors, was recommended as second-line therapy [36].