title: Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up, what is down?
abstract: The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency is the rationale for replacing endogenous incretins with GLP-1 receptor agonists or re-normalising active GLP-1 concentrations with dipeptidyl peptidase-4 inhibitors. This review summarises the literature on this topic, including a meta-analysis of published studies on GLP-1 secretion in individuals with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some of the variations in published findings of group differences in GLP-1 responses to nutrient intake.
authors.affiliation: Diabeteszentrum Bad Lauterberg, Bad Lauterberg im Harz, Germany. M.Nauck@diabeteszentrum.de
authors.forename: M A
authors.initials: MA
authors.lastname: Nauck
authors.forename: I
authors.initials: I
authors.lastname: Vardarli
authors.forename: C F
authors.initials: CF
authors.lastname: Deacon
authors.forename: J J
authors.initials: JJ
authors.lastname: Holst
authors.forename: J J
authors.initials: JJ
authors.lastname: Meier
mesh_terms: D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D006801:Humans; D054795:Incretins / Q000378:metabolism; D015201:Meta-Analysis as Topic; D008954:Models, Biological
chemical_list: D054795:Incretins; D052216:Glucagon-Like Peptide 1