Incretin mimetics and dipeptidyl peptidase-IV inhibitors: potential new therapies for type 2 diabetes mellitus.
The emergence of the glucoregulatory hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide has expanded our understanding of glucose homeostasis. In particular, the glucoregulatory actions of the incretin hormone GLP-1 include enhancement of glucosedependent insulin secretion, suppression of inappropriately elevated glucagon secretion, slowing of gastric emptying, and reduction of food intake. Two approaches have been developed to overcome rapid degradation of GLP-1. One is the use of agents that mimic the enhancement of glucose-dependent insulin secretion, and potentially other antihyperglycemic actions of incretins, and the other is the use of dipeptidyl peptidase-IV inhibitors, which reduce the inactivation of GLP-1, increasing the concentration of endogenous GLP-1. The development of incretin mimetics and dipeptidyl peptidase-IV inhibitors opens the door to a new generation of antihyperglycemic agents to treat several otherwise unaddressed pathophysiologic defects of type 2 diabetes mellitus. We review the physiology of glucose homeostasis, emphasizing the role of GLP-1, the pathophysiology of type 2 diabetes mellitus, the clinical shortcomings of current therapies, and the potential of new therapies -- including the newly approved incretin mimetic exenatide -- that elicit actions similar to those of GLP-1.
Triplitt
Curtis
C
Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, and Texas Diabetes Institute, San Antonio, Texas 78229, USA. curtis.triplitt@uhs-sa.com
Wright
Alison
A
Chiquette
Elaine
E
D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006706:Homeostasis; D007004:Hypoglycemic Agents / Q000627:therapeutic use*
D004791:Enzyme Inhibitors; D007004:Hypoglycemic Agents; D052216:Glucagon-Like Peptide 1; D018819:Dipeptidyl Peptidase 4; D005947:Glucose