One year of liraglutide treatment offers sustained and more effective glycaemic control and weight reduction compared with sitagliptin, both in combination with metformin, in patients with type 2 diabetes: a randomised, parallel-group, open-label trial

P>Aim: The aim of this study was to compare the efficacy and safety of once-daily human glucagon-like peptide-1 analogue liraglutide with dipeptidyl peptidase-4 inhibitor sitagliptin, each added to metformin, over 52 weeks in individuals with type 2 diabetes. Methods: In an open-label, parallel-group trial, metformin-treated participants were randomised to liraglutide 1.2 mg/day (n = 225), liraglutide 1.8 mg/day (n = 221) or sitagliptin 100 mg/day (n = 219) for 26 weeks (main phase). Participants continued the same treatment in a 26-week extension. Results: Liraglutide (1.2 or 1.8 mg) was superior to sitagliptin for reducing HbA(1c) from baseline (8.4-8.5%) to 52 weeks: -1.29% and -1.51% vs. -0.88% respectively. Estimated mean treatment differences between liraglutide and sitagliptin were as follows: -0.40% (95% confidence interval -0.59 to -0.22) for 1.2 mg and -0.63% (-0.81 to -0.44) for 1.8 mg (both p < 0.0001). Weight loss was greater with liraglutide 1.2 mg (-2.78 kg) and 1.8 mg (-3.68 kg) than sitagliptin (-1.16 kg) (both p < 0.0001). Diabetes Treatment Satisfaction Questionnaire scores increased significantly more with liraglutide 1.8 mg than with sitagliptin (p = 0.03). Proportions of participants reporting adverse events were generally comparable; minor hypoglycaemia was 8.1%, 8.3% and 6.4% for liraglutide 1.2 mg, 1.8 mg and sitagliptin respectively. Gastrointestinal side effects, mainly nausea, initially occurred more frequently with liraglutide, but declined after several weeks. Conclusion: Liraglutide provides greater sustained glycaemic control and body weight reduction over 52 weeks. Treatment satisfaction was significantly greater with 1.8 mg liraglutide, similar to 26-week results. The safety profiles of liraglutide and sitagliptin are consistent with previous reports.