Pathophysiological Study of the Increase in Pancreatic Volume in Type 2 Diabetes Treatments.

The incretinomimetics and the inhibitors of dipeptidyl peptidase-4 (DPP-4) are new treatments for diabetes. The incretinomimetics are analogs of Glucagon Like Peptide 1 (GLP-1), secreted from endocrine L-cells of the colon and terminal ileum peptide. Serum GLP-1 increase rapidly after a meal. But its degradation is also fast. It acts on the hypothalamus by reducing appetite and food intake, on the stomach by delaying gastric emptying and the level of beta islet cells by inducing the synthesis and secretion of insulin (1). The incretinomimetics currently marketed in Belgium (March 2014) are exenatide (Byetta ®), liraglutide (Victoza ®), lixisenatide (Lyxumia ®) and very soon (April 2014) extended-release exenatide (Bydureon ®). The DPP-4 prevent the degradation of GLP-1. The DPP-4 currently marketed (March 2014) are sitagliptin (Januvia ®), vildagliptin (Galvus ®), saxagliptin (Onglyza ®) and (Trajenta ®) linagliptin.

In diabetic patients, these treatments allow a significant reduction in fasting plasma glucose and postprandial, with a low risk of hypoglycemia and no weight gain (and sometimes weight loss) (2).

Their place in the management of type 2 diabetes is considered or in combination with metformin, when diabetes is inadequately controlled despite maximal dose of the latter, or when patients are intolerant to metformin.

A study to evaluate the safety of 'incretinomimetics therapy "showed an increase in pancreatic weight of 40% (3). Indeed, in a cohort of 34 pancreatic organ donors from brain death, 20 patients were diabetic and 8 as incretin mimetics for over 1 year. An increase in pancreatic mass on average 40% was observed compared to diabetic patients without this treatment.

This study also demonstrated an increase in the mass of beta cells without restoring insulin function. The advanced for this mass increase without a significant increase of cell size is a hypothesis decreased apoptosis of beta cells.