DPP4 and Hypoglycemia: Early clinical trials with the GLP-1 analogue exenatide, and the dipeptidyl-peptidase 4 inhibitors (such as sitagliptin and vildagliptin, which elevate endogenous GLP-1 concentrations by preventing its breakdown) do not seem to be associated with increased risk of hypoglycaemia when used as monotherapy [49] or in combination with insulin sensitizers (metformin and PPARγ-agonists) [50–54] in short-term clinical studies of between 24 and 52 weeks, although studies with exanatide have demonstrated increased risk of hypoglycaemia if used in association with SUs [55,56].