Short-Term Effects of Liraglutide versus Vildagliptin on Insulin Secretion and Sensitivity in Type 2 Diabetes: A Single Blinded Randomized Controlled Trial (LIRAVIS Study)

Background: We aimed to evaluate the short-term metabolic effects of a GLP-1a, (liraglutide) versus a DPP-4i, (vildagliptin) in a group of sub-Saharan type 2 diabetes patients. Methods: We conducted a randomized controlled single blinded clinical trial in 14 uncontrolled type 2 diabetes patients (HbA1c ≥ 53 mmol/mol) with mean duration of diabetes of 8 [1 - 12] years and median age of 57 [49 - 61] years. Baseline treatment consisted of metformin in monotherapy or metformin plus sulfonylureas. Participants were randomly allocated to 2 groups of add-on 1.2 mg/day subcutaneous liraglutide in group 1 or 100 mg/day of oral vildagliptin in group 2 for 2 weeks. In all participants, insulin secretion in response to mixed meal tolerance test, insulin sensitivity by 80 mU/m²/min hyperinsulinemic-euglycemic clamp, body composition, and lipid profile were measured before and after intervention. Results: At the end of intervention, insulin sensitivity remained unchanged both with liraglutide from 6.6 [4.2 - 7.9] to 6.9 [4.3 - 10.8] mg/kg/min; p = 0.61 and vildagliptin from 7.1 [5.3 - 9.0] to 6.5 [5.6 - 9.4] mg/kg/min (p = 0.86). The area under the C-peptide curve varied from 5.5 [1.0 - 10.9] to 14.9 [10.8 - 17.2] nmol/L/120min, p = 0.09 in group 1 and from 1.1 [0.5 - 14.1] to 13.0 [9.6 - 16.9] nmol/L/120min (p = 0.17) in group 2. LDL Cholesterol levels decreased significantly with liraglutide from 0.85 g/L [0.51 - 1.02] to 0.54 g/L [0.50 - 0.73] (p = 0.04) but not with Vildagliptin. Body weight tended to decrease in group 1 (−0.6 kg) versus modest increase in group 2 (+1.1 kg). Conclusion: Short-term metabolic effects of Liraglutide and Vildagliptin add-on therapy are comparable in sub-Saharan type 2 diabetes patients with a more favorable trend for Liraglutide on body weight, lipid profile, and insulin secretion.