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

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.