Clinical application of incretin-based therapy: therapeutic potential, patient selection and clinical use

Incretin-based therapies address the progressive nature of type 2 diabetes mellitus, not only by addressing glucose control but also with weight-neutral (i.e., dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin) and weight-reducing effects (i.e., glucagonlike peptide-1 [GLP-1] receptor agonists exenatide and liraglutide). Preclinical data suggest that incretin-based therapies may also preserve beta-cell function, holding promise of a truly disease-modifying therapy. This article examines clinical trial data and accepted algorithms with a view toward elucidating the application of these agents in routine clinical practice. We propose a systematic approach to treatment, addressing (1) patient selection, (2) optimal treatment combinations, and (3) timing and guidance for both initiation and intensification of therapy. The GLP-1 receptor agonists, for example, could be particularly beneficial in patients whose weight significantly increases cardiovascular risk. Early use of these agents may be effective in preventing diabetes in those at risk, or in halting or retarding disease progression in patients with frank diabetes. Additional clinical investigation will be required to test such hypotheses. Given the ever-increasing incidence of diabetes worldwide, the link between obesity and the development of type 2 diabetes, and the need for more effective, weight-focused, convenient and sustainable treatments, the data from such studies will be invaluable to further clarify the role of the incretins in the management of patients with type 2 diabetes.