Retrospective analysis of safety and efficacy of insulin‐to‐liraglutide switch in Japanese type 2 diabetes: A caution against inappropriate use in patients with reduced β‐cell function

AIMS/INTRODUCTION The safety and efficacy of insulin-to-liraglutide switch in type 2 diabetes has not been studied adequately. Here, we retrospectively characterize clinical parameters that might predict insulin-to-liraglutide treatment switch without termination due to hyperglycemia, and examine the effects of switching the therapies on glycated hemoglobin (HbA1c) and bodyweight in Japanese type 2 diabetes. MATERIALS AND METHODS Japanese type 2 diabetes patients who underwent the switch of therapy were evaluated for their clinical data including β-cell function-related indices, such as increment of serum C-peptide during glucagon stimulation test (GST-ΔCPR). HbA1c and bodyweight were analyzed in patients continuing with liraglutide after switching from insulin for 12 weeks. RESULTS Of 147 patients, 28 failed in the switch due to hyperglycemia, nine failed because of other reasons and 110 continued with liraglutide for the 12-week period. Patients failing in the switch due to hyperglycemia showed longer duration and higher daily insulin dose, as well as lower GST-ΔCPR. Receiver-operating characteristic analysis showed that GST-ΔCPR of 1.34 ng/mL is a cut-off point for insulin-to-liraglutide switch without termination due to hyperglycemia. In patients continuing liraglutide for 12 weeks, the switch significantly reduced HbA1c and bodyweight with no severe hypoglycemia, irrespective of sulfonylurea co-administration, body mass index, duration and total daily insulin dose. The switch also significantly reduced the percentage of body fat and visceral fat areas. CONCLUSIONS Insulin-to-liraglutide switch can improve glycemic control and reduce bodyweight in Japanese type 2 diabetes patients. However, caution must be taken with the switch in patients with reduced insulin secretory capacity as predicted by GST-ΔCPR.