An Open-label Longitudinal Study on the Efficacy of Switching from Insulin Glargine or Detemir to Degludec in Type 2 Diabetes Mellitus

Objective Insulin degludec (IDeg), a new long-acting basal insulin, and FlexTouch, a new injection device, recently became available in Japan. The efficacy and usefulness of IDeg and FlexTouch, compared with insulin glargine or detemir, were assessed in patients with type 2 diabetes mellitus. Methods We performed an open-label longitudinal trial in 20 patients. After informed consent was obtained, all subjects recorded their self-monitoring data of the blood glucose (BG) level; thereafter, basal insulin was replaced by an IDeg-prefilled FlexTouch with the same dose and duration of time (2 weeks). After using FlexTouch, the patients were provided a device-specific questionnaire. Results The patients were divided into two groups according to the dose of basal insulin (>= 10 U and <10 U). Although the mean fasting BG levels were unchanged, the mean BG levels before basal insulin injection and its standard deviation were significantly reduced after switching to IDeg in the patients receiving a higher dose of basal insulin (mean BG before basal insulin injection: 164 to 144 mg/dL, p=0.002; mean standard deviation: 32 to 22, p=0.031); however, this difference was not observed in the patients receiving a lower dose. The patients with a shorter duration of diabetes and a single injection of insulin preferred FlexTouch compared with conventional insulin devices. Conclusion Replacing basal insulin with IDeg is useful for the stable and accurate control of blood glucose levels in type 2 diabetes for those receiving a higher dose of basal insulin. Furthermore, the patients with a shorter duration of diabetes and a single insulin injection preferred FlexTouch.