Inhibition of DPP-4 with vildagliptin improved insulin secretion in response to oral as well as "isoglycemic" intravenous glucose without numerically changing the incretin effect in patients with type 2 diabetes.

Abstract

BACKGROUND AND AIMS:

Dipeptidyl peptidase-4 (DPP-4) inhibitors block the degradation of glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. The aim of the present study was to quantitatively assess the incretin effect after treatment with the DPP-4 inhibitor vildagliptin (V) or placebo (P) in patients with type 2 diabetes.

MATERIALS AND METHODS:

Twenty-one patients (three women, 18 men) with type 2 diabetes previously treated with metformin (mean age, 59 yr; body mass index, 28.6 kg/m(2); glycosylated hemoglobin, 7.3%) were studied in a two-period crossover design. They received 100 mg V once daily or P for 13 d in randomized order. The incretin effect was measured on d 12 (75-g oral glucose) and d 13 ("isoglycemic" iv glucose) based on insulin and C-peptide determinations and insulin secretion rates (ISR).

RESULTS:

V relative to P treatment significantly increased intact incretin concentrations after oral glucose and insulin secretory responses to both oral glucose and isoglycemic iv glucose (e.g. AUC(ISR oral), by 32.7%, P = 0.0006; AUC(ISR iv), by 33.1%, P = 0.01). The numerical incretin effect was not changed (IE(ISR), V vs. P, 35.7 ± 4.9 and 34.6 ± 4.0%, P = 0.80).

CONCLUSIONS:

DPP-4 inhibition augmented insulin secretory responses both after oral glucose and during isoglycemic iv glucose infusions, with no net change in the incretin effect. Thus, slight variations in basal incretin levels may be more important than previously thought. Or, DPP-4 inhibitor-induced change in the incretin-related environment of islets may persist overnight, augmenting insulin secretory responses to iv glucose as well. Alternatively, yet unidentified mediators of DPP-4 inhibition may have caused these effects.

• Authors: Irfan Vardarli, Michael A Nauck, Lars D Köthe, Carolyn F Deacon, Jens J Holst, Anja Schweizer, James E Foley
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 96 Issue 4 Pg. 945-54 (Apr 2011) ISSN: 1945-7197 [Electronic] United States
• PMID: 21239518 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Glucose
• Dipeptidyl-Peptidase IV Inhibitors
• Incretins
• Insulin
• Nitriles
• Pyrrolidines
• DPP4 protein, human
• Dipeptidyl Peptidase 4
• Vildagliptin
• Glucose
• Adamantane

Topics

• Adamantane (administration & dosage, analogs & derivatives, pharmacology)
• Administration, Oral
• Adult
• Aged
• Blood Glucose (drug effects, metabolism)
• Cross-Over Studies
• Diabetes Mellitus, Type 2 (blood, drug therapy, metabolism)
• Dipeptidyl Peptidase 4 (metabolism)
• Dipeptidyl-Peptidase IV Inhibitors (administration & dosage, pharmacology)
• Female
• Glucose (administration & dosage)
• Humans
• Incretins (pharmacology)
• Injections, Intravenous
• Insulin (metabolism)
• Insulin Secretion
• Male
• Middle Aged
• Nitriles (administration & dosage, pharmacology)
• Pyrrolidines (administration & dosage, pharmacology)
• Up-Regulation (drug effects)
• Vildagliptin