Incretins and other peptides in the treatment of diabetes

Diabet Med. 2007 Mar;24(3):223-32. doi: 10.1111/j.1464-5491.2006.02071.x.

Abstract

Glucagon-like peptide-1 (7-36) amide (GLP-1) is a gut hormone, released postprandially,which stimulates insulin secretion and insulin gene expression as well as pancreatic B-cell growth. Together with glucose-dependent insulinotropic polypeptide (GIP), it is responsible for the incretin effect which is the augmentation of insulin secretion following oral administration of glucose. Patients with Type 2 diabetes have greatly impaired or absent incretin-mediated insulin secretion which is mainly as a result of decreased secretion of GLP-1. However,the insulinotropic action of GLP-1 is preserved in patients with Type 2 diabetes,and this has encouraged attempts to treat Type 2 diabetic patients with GLP-1.GLP-1 also possesses a number of potential advantages over existing agents for the treatment of Type 2 diabetes. In addition to stimulating insulin secretion and promoting pancreatic B-cell mass, GLP-1 suppresses glucagon secretion,delays gastric emptying and inhibits food intake. Continuous intravenous and subcutaneous administration significantly improves glycaemic control and causes reductions in both HbA1c and body weight. However, GLP-1 is metabolized extremely rapidly in the circulation by the enzyme dipeptidyl peptidase IV(DPP-IV). This is the probable explanation for the short-lived effect of single doses of native GLP-1, making it an unlikely glucose-lowering agent. The DPP-IV resistant analogue, exenatide, has Food and Drug Administration (FDA) approval for the treatment of Type 2 diabetes and selective DPP-IV inhibitors are underdevelopment. Both approaches have demonstrated remarkable efficacy in animal models and human clinical studies. Both are well tolerated and appear to have advantages over current therapies for Type 2 diabetes, particularly in terms of the effects on pancreatic B-cell restoration and potential weight loss.

Publication types

  • Review

MeSH terms

  • Diabetes Mellitus, Type 2 / drug therapy*
  • Dipeptidyl Peptidase 4 / metabolism
  • Exenatide
  • Glucagon-Like Peptide 1 / metabolism
  • Glucagon-Like Peptide 1 / therapeutic use*
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Insulin-Secreting Cells / metabolism*
  • Peptides / metabolism
  • Peptides / therapeutic use
  • Venoms / metabolism
  • Venoms / therapeutic use
  • Weight Loss / drug effects*

Substances

  • Hypoglycemic Agents
  • Peptides
  • Venoms
  • Glucagon-Like Peptide 1
  • Exenatide
  • Dipeptidyl Peptidase 4