NCT02749032

Feed-Back Suppression of Meal-Induced Glucagon-like Peptide 1 (GLP-1) Secretion

Feed-Back Suppression of Meal-Induced GLP-1 Secretion Mediated Through Elevations in Intact GLP-1 Caused by Dipeptidyl Peptidase 4 (DPP-4) Inhibition: A Randomized, Prospective Comparison of Sitagliptin and Vildagliptin Treatment

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 24 (actual)
• Sponsor: Michael A. Nauck · Academic / Other
• Sex: All
• Age: 30 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

The present study is a phase I, single-centre, double-blind, randomized, cross-over (3 treatments, 3 treatment periods and 6 sequences), stratified (background medication: metformin vs. diet-only), placebo-controlled study, comparing periods lasting 6-9 days on treatment with repeated doses of vildagliptin, sitagliptin, or placebo, with wash-out periods between treatment periods lasting 21 days minimum. The study was designed to directly compare the effects of vildagliptin and sitagliptin on incretin hormone responses, glycaemia, and insulin as well as glucagon secretory responses in patients with type 2 diabetes.

Detailed description

Design. The present study is a phase I, single-centre, double-blind, randomized, cross-over (3 treatments, 3 treatment periods and 6 sequences), stratified (background medication: metformin vs. diet-only), placebo-controlled study, comparing periods lasting 6-9 days on treatment with repeated doses of vildagliptin, sitagliptin, or placebo, with wash-out periods between treatment periods lasting 21 days minimum. Experimental procedures. Meal tests were performed in the morning after an overnight fast. The standardized mixed meal was composed of 2 eggs (100 g), 1 slice (50 g) of whole grain rye bread, 1 slice (50 g) of rye flour bread, 10 g of fat-reduced margarine, 20 g of boiled ham, and 25 g of diet jam, amounting to 450 kcal, 50 % carbohydrate, 20 % protein, and 30 % fat (based on calorie count). Patients were allowed to drink tea (black or fruit-based) or de-caffeinated coffee ad libitum. Blood sampling. Plasma glucose was determined in capillary samples taken from hyperaemic ear lobes. Venous blood was collected from indwelling venous cannulas placed in a distal forearm vein, for the determination of insulin, C-peptide, glucagon, GLP-1 (total), GLP-1 (intact), glucose-dependent insulinotropic polypeptide (GIP) (total), GIP (intact), and free fatty acids. After drawing basal blood specimens at -15 and 0 min, blood was taken at 15, 30, 45, 60, 90, 120, 180, and 240 min. Laboratory determinations. Glucose, insulin, C-peptide, total GLP-1 (C-terminally directed assay), intact GLP-1 (sandwich ELISA), total GIP (C-terminally directed assay), intact GIP (N-terminally directed assay) and glucagon were determined.

Conditions

• Type 2 Diabetes

Interventions

Type	Name	Description
OTHER	Mixed meal test	Mixed meal test were performed in the morning after an overnight fast. The standardized mixed meal was composed of 2 eggs (100 g), 1 slice (50 g) of whole grain rye bread, 1 slice (50 g) of rye flour bread, 10 g of fat-reduced margarine, 20 g of boiled ham, and 25 g of diet jam, amounting to 450 kcal, 50 % carbohydrate, 20 % protein, and 30 % fat (based on calorie count). Patients were allowed to drink tea (black or fruit-based) or de-caffeinated coffee ad libitum.
DRUG	Vildagliptin	Vildagliptin (50 mg per tablet) was administered orally twice daily (15 minutes prior to breakfast or test meal, on the last day of treatment period) and without a defined temporal relation to dinner in the evening, irrespective of the stratum defined by the background diabetes treatment.
DRUG	Sitagliptin	The dosage of sitagliptin depended on the stratum defined by the background diabetes medication. In patients treated with diet and exercise (no other glucose-.lowering medication), sitagliptin was given as one 100 mg in the morning (15 minutes prior to breakfast or the test meal, on the last day of the treatment period), and a corresponding placebo tablet was administered in the evening (no temporal relation to dinner required).
DRUG	Placebo	Placebo was administered orally twice daily: 15 minutes prior to breakfast or the test meal on the last day of treatment period) and one dose in the evening (no temporal relation to dinner required).
DRUG	Metformin	For patients continuing with pre-existing metformin treatment, 1000 mg film coated tablets from commercial sources. In half of the patients (stratum: metformin as background medication), metformin was administered orally twice daily at 1000 mg of active compound during of after breakfast and dinner.
OTHER	Diet and exercise	Patients treated their diabetes mellitus type 2 with diet/exercise only

Timeline

• Start date: 2011-11-01
• Primary completion: 2014-03-01
• First posted: 2016-04-22
• Last updated: 2016-04-22

Locations

1 site across 1 country: Germany