Four Weeks of Treatment With Liraglutide Reduces Insulin Dose Without Loss of Glycemic Control in Type 1 Diabetic Patients With and Without Residual β-Cell Function

OBJECTIVE: To investigate the effect of 4 weeks of treatment with liraglutide on insulin dose and glycemic control in type 1 diabetic patients with and without residual β-cell function. RESEARCH DESIGN AND METHODS: Ten type 1 diabetic patients with residual β-cell function (C-peptide positive) and 19 without (C-peptide negative) were studied. All C-peptide-positive patients were treated with liraglutide plus insulin, whereas C-peptide-negative patients were randomly assigned to liraglutide plus insulin or insulin monotherapy. Continuous glucose monitoring with identical food intake and physical activity was performed before (week 0) and during (week 4) treatment. Differences in insulin dose; HbA₁c; time spent with blood glucose 10, and 3.9-9.9 mmol/L; and body weight were evaluated. RESULTS: Insulin dose decreased from 0.50 ± 0.06 to 0.31 ± 0.08 units/kg per day (P < 0.001) in C-peptide-positive patients and from 0.72 ± 0.08 to 0.59 ± 0.06 units/kg per day (P < 0.01) in C-peptide-negative patients treated with liraglutide but did not change with insulin monotherapy. HbA₁c decreased in both liraglutide-treated groups. The percent reduction in daily insulin dose was positively correlated with β-cell function at baseline, and two patients discontinued insulin treatment. In C-peptide-positive patients, time spent with blood glucose