Effects of Dipeptidyl Peptidase-4 Inhibition on Gastrointestinal Function, Meal Appearance, and Glucose Metabolism in Type 2 Diabetes

  1. Adrian Vella1,
  2. Gerlies Bock1,
  3. Paula D. Giesler1,
  4. Duane B. Burton2,
  5. Denise B. Serra3,
  6. Monica Ligueros Saylan3,
  7. Beth E. Dunning4,
  8. James E. Foley3,
  9. Robert A. Rizza1 and
  10. Michael Camilleri2
  1. 1Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic College of Medicine, Rochester, Minnesota
  2. 2Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota
  3. 3Novartis Pharmaceuticals, East Hanover, New Jersey
  4. 4PharmaWrite, Princeton, New Jersey
  1. Address correspondence and reprint requests to Adrian Vella, MD, Endocrine Research Unit, 5 Jo-194, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905. E-mail: vella.adrian{at}mayo.edu

Abstract

OBJECTIVE— We sought to determine whether alterations in meal absorption and gastric emptying contribute to the mechanism by which inhibitors of dipeptidyl peptidase-4 (DPP-4) lower postprandial glucose concentrations.

RESEARCH DESIGN AND METHODS— We simultaneously measured gastric emptying, meal appearance, endogenous glucose production, and glucose disappearance in 14 subjects with type 2 diabetes treated with either vildaglipitin (50 mg b.i.d.) or placebo for 10 days using a double-blind, placebo-controlled, randomized, crossover design.

RESULTS— Fasting (7.3 ± 0.5 vs. 7.9 ± 0.5 mmol/l) and peak postprandial (14.1 ± 0.6 vs. 15.9 ± 0.9 mmol/l) glucose concentrations were lower (P < 0.01) after vildagliptin treatment than placebo. Despite lower glucose concentrations, postprandial insulin and C-peptide concentrations did not differ during the two treatments. On the other hand, the integrated (area under the curve) postprandial glucagon concentrations were lower (20.9 ± 1.6 vs. 23.7 ± 1.3 mg/ml per 5 h, P < 0.05), and glucagon-like peptide 1 (GLP-1) concentrations were higher (1,878 ± 270 vs. 1,277 ± 312 pmol/l per 5 h, P = 0.001) during vildagliptin administration compared with placebo. Gastric emptying and meal appearance did not differ between treatments.

CONCLUSIONS— Vildagliptin does not alter gastric emptying or the rate of entry of ingested glucose into the systemic circulation in humans. DPP-4 inhibitors do not lower postprandial glucose concentrations by altering the rate of nutrient absorption or delivery to systemic circulation. Alterations in islet function, secondary to increased circulating concentrations of active GLP-1, are associated with the decreased postprandial glycemic excursion observed in the presence of vildagliptin.

Footnotes

  • Published ahead of print at http://diabetes.diabetesjournals.org on 14 February 2007. DOI: 10.2337/db07-0136.

  • A.V. has received research grants from Merck, Eli Lilly, Novartis, and Sanofi-Aventis and has consulted for Eli Lilly. R.A.R. is a member of the advisory boards of Merck, Novo Nordisk, Takeda, Mankind, and Eli Lilly and a consultant for Abbott and Eli Lilly. J.E.F., M.L.S., and D.B.S. are employees of and hold stock in Novartis. B.E.D. is a subcontractor for and holds stock in Novartis, and B.E.D. holds stock in Merck.

  • Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/db07-0136.

  • The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

    • Accepted February 3, 2007.
    • Received February 3, 2007.
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  1. Diabetes vol. 56 no. 5 1475-1480
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