The document discusses the role of incretins in the management of diabetes. It describes how incretins like GLP-1 and GIP are released after eating to stimulate insulin production and suppress glucagon levels. However, in type 2 diabetes patients, incretin levels and effects are reduced. DPP-4 inhibitors are discussed as a treatment approach that blocks the breakdown of incretins, thereby increasing their levels and effects. Studies show that DPP-4 inhibitors like sitagliptin prolong the levels and actions of incretins, lowering glucose levels and being weight neutral. They represent a new class of diabetes drugs that mimic the normal incretin response.