In 2008, the Food and Drug Administration proposed a 2-step process for the approval of oral glucose-lowering therapies for type 2 diabetes that included an initial approval contingent on effective hemoglobin A 1c reduction and then a postmarketing cardiovascular outcomes trial with predefined end points, longer follow-up, and a higher risk population to demonstrate "noninferiority" to placebo. Incretin-based therapies were the first drugs to be evaluated under the new guidance policy. Glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide are incretin hormones secreted from the small intestine after meals and lower glucose levels by increasing β-cell insulin secretion, decreasing glucagon release, improving satiety, and slowing gut motility. Glucagon-like peptide-1 is rapidly deactivated by the enzyme dipeptidyl peptidase 4 (DPP4). The incretin axis can be pharmacologically enhanced either through injections of GLP-1 mimetics to achieve supraphysiologic levels or by inhibition of DPP4, which prolongs the half-life of physiologic levels of GLP-1, thus prolonging its action, although to a lesser extent than exogenous GLP-1 agonist. In preclinical experiments, both GLP-1 agonists and DPP4 inhibitors promoted nonglycemic-mediated cardioprotective actions. 1 There were no signals of any cardiovascular harm in any of the incretin-based clinical development programs and, in fact, there were data to suggest direct cardioprotective and vasculoprotective benefits. 2 To date, 3 DPP4 inhibitors (saxagliptin, 3 alogliptin, 4 and sitagliptin 5) and 1 GLP-1 agonist (lixisenatide 6) have published the primary results of their cardiovascular outcomes trials. On balance, the studies were more similar than different. Two studies enrolled patients following an acute coronary syndrome, 4,6 while the other 2 enrolled stable patients of whom most had established cardiovascular disease. 3,5 The primary results of the trials were also similar. Each easily met the noninferiority boundary with an upper bound of the 95% CI well below 1.3 for their primary and secondary composite end points. In fact, the event curves of each trial seemed to intertwine and the hazard ratios all fell within a few hundredths of a decimal point of 1.00. These safety data alone in almost 43 000 patients with type 2 diabetes are an important advance in understanding the cardiovascular risk profile of drugs to treat diabetes. Among the different trial results, the most unexpected finding was a 27% increased relative risk of hospitalization for