Kelly A, Sheikh S, Stefanovski D, et al. - In pancreatic insufficient cystic fibrosis (PI-CF), a possible contribution of impaired incretin secretion to the defective insulin secretion and abnormal glucose tolerance (AGT) is suggested that correlate with worse clinical outcomes . Researchers herein examined if dipeptidyl peptidase-4 (DPP-4) inhibitor-induced elevations in intact incretin hormone (glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]) concentrations augment insulin secretion and glucagon suppression and lower post prandial glycemia in PI-CF with AGT. They randomized 26 adults from Children’s Hospital of Philadelphia and University of Pennsylvania CF Center with PI-CF and AGT (defined by oral glucose tolerance test glucose [mg/dL]: early glucose intolerance [1-hour ≥155 & 2-hour <140], impaired glucose tolerance [2-hour ≥140 and <200 mg/dl], or diabetes [2-hour ≥200]) to a 6-month double-blind trial of DPP-4 inhibitor sitagliptin 100 mg daily or matched-placebo. Of these, 24 completed the trial (n = 12 sitagliptin; n=12 placebo). Outcomes revealed that sitagliptin intervention augmented meal-related incretin responses in glucose intolerant PI-CF, along with improved early insulin secretion and glucagon suppression without affecting postprandial glycemia.