Japanese Clinical Medicine

Objective: Liraglutide (glucagon-like peptide-1 [GLP-1] receptor agonist) and sitagliptin (dipeptidyl peptidase-4 inhibitor) are approved in Japan for treating type 2 diabetes mellitus (T2DM). We compared the efficacy and safety of adding liraglutide or sitagliptin to a sulfonylurea in Japanese T2DM patients.

Methods: Patients aged 18 to <80 years with hemoglobin A1c (HbA1c; National Glycohemoglobin Standardization Program [NGSP]) of 6.9–9.4%, body mass index ≤35 kg/m2, and treatment with a sulfonylurea and/or one or two non-sulfonylurea oral antidiabetic drugs for greater than or equal to eight weeks before enrollment were eligible. Patients were randomized in an open-label manner to either 0.9 mg/day liraglutide (n = 50) or 50–100 mg/day sitagliptin (n = 49) and were treated for 24 weeks. Non-sulfonylureas were discontinued before randomization. Patients using other oral antidiabetic drugs started sulfonylurea treatment. The primary endpoint was the change in HbA1c from baseline to Week 24.

Results: HbA1c decreased in both groups, and the reduction was significantly greater throughout in the liraglutide group except for Week 24 (0.59 ± 0.80 vs. 0.24 ± 0.94%; P = 0.0525). Fasting plasma glucose (FPG) decreased significantly in the liraglutide group compared with the sitagliptin group (-21.15 ± 31.22 vs. +0.46 ± 39.39 mg/dL; P = 0.0014). Homeostasis model assessment of β cell function and C-peptide increased significantly in the liraglutide group but not in the sitagliptin group. Hypoglycemic symptoms and adverse events occurred in four and nine patients, respectively, in the liraglutide group, and in two and five patients, respectively, in the sitagliptin group.

Conclusion: Treatment with liraglutide or sitagliptin together with a sulfonylurea improved HbA1c in Japanese T2DM patients in primary care. Both drugs were associated with low rates of adverse events and hypoglycemia. The improvement in β cell function probably contributed to the improvement in glycemic control in the liraglutide group.