Accordingly, in short-term studies (1–9 days in duration), head-to-head comparisons in patients with T2DM have shown that when used at their therapeutic doses, sitagliptin (100 mg once daily) and saxagliptin (5 mg once daily) all achieve the same maximal and trough levels of DPP4 inhibition [84] and are associated with similar enhancements of intact incretin hormone concentrations [85,86]. Here, DPP4 is linked to type 2 diabetes mellitus.