The once‐daily human glucagon‐like peptide‐1 analog,liraglutide, improves β‐cell function in Japanese patients with type 2 diabetes

Aims/Introduction: β‐cell function was evaluated by homeostasis model assessment of β‐cell function (HOMA‐B) index, proinsulin:insulin and proinsulin:C‐peptide ratios in adult, Japanese type 2 diabetes patients receiving liraglutide. Materials and Methods: Data from two randomized, controlled clinical trials (A and B) including 664 Japanese type 2 diabetes patients (mean values: glycated hemoglobin HbA_1c] 8.61–9.32%; body mass index BMI] 24.4–25.3 kg/m²) were analyzed. In two 24‐week trials, patients received liraglutide 0.9 mg (n = 268) or glibenclamide 2.5 mg (n = 132; trial A), or liraglutide 0.6, 0.9 mg (n = 176) or placebo (n = 88) added to previous sulfonylurea therapy (trial B). Results: Liraglutide was associated with improved glycemic control vs sulfonylurea monotherapy or placebo. In liraglutide‐treated groups in trials A and B, area under the curve (AUC) _{insulin 0–3 h} was improved (P < 0.001 for all) and the AUC_{insulin 0–3 h}:AUC_{glucose 0–3 h} ratio was increased (estimated treatment difference liraglutide–comparator] 0.058 0.036, 0.079]). HOMA‐B significantly increased with liraglutide relative to comparator in trial B (P < 0.05), but not in trial A. The reduction in fasting proinsulin:insulin ratio was 50% greater than in comparator groups. Conclusions: In Japanese type 2 diabetes patients, liraglutide was associated with effective glycemic control, restoration of prandial insulin response and indications of improved β‐cell function. This trial was registered with Clinicaltrials.gov (trial A: no. NCT00393718/JapicCTI‐060328 and trial B: no. NCT00395746/JapicCTI‐060324). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00193.x, 2012)