Clinical Characteristics of Withdrawal of Basal Insulin Therapy Among Japanese Patients with Type 2 Diabetes: A Multicenter Retrospective Observational Study

INTRODUCTION: This study aimed to examine retrospectively the clinical backgrounds of Japanese patients with type 2 diabetes (T2D) who successfully withdrew from insulin use after being started on basal insulin in an outpatient setting. METHODS: The study population comprised 376 insulin-naïve patients who were started on basal insulin (glargine U100, glargine U300, or degludec) for the management of T2D and followed the treatment regimen for at least 6 months in 13 institutions in Japan. The clinical courses of the study participants were compared based on outpatient clinic medical records for the three different types of basal insulin prescribed by categorizing the participants into two groups retrospectively: those who successfully withdrew from insulin therapy and those who did not, during a 6-month observation period. The clinical determinants for insulin withdrawal were assessed using a Cox proportional hazard model. RESULTS: Glycated hemoglobin was improved in all participants regardless of basal insulin type. Of the 376 study participants, 61 successfully withdrew from basal insulin therapy. After adjustment was made for several confounders, the positive determinant factors for successful withdrawal of insulin were short duration of diabetes and high body mass index at the start of study, and the negative determinant factor was use of insulin secretagogues at the start. The types of basal insulin used by the study participants were not significant determinants of successful insulin withdrawal in this study. CONCLUSIONS: Use of basal insulin is a powerful option for the treatment of T2D. In patients with high BMI and/or short duration of diabetes, short-term insulin therapy is a promising strategy for the treatment of T2D before the initiation of insulin secretagogues, since such patients have the potential to successfully withdraw from basal insulin use even in an outpatient setting.