Abstract
INTRODUCTION: Basal-bolus (BB) and premixed insulin regimens may lower fasting plasma glucose (FPG) and postprandial plasma glucose (PPG), but are complex to use and associated with weight gain and hypoglycaemia. Although randomized controlled trials and prospective observational studies in insulin-naïve Japanese patients with type 2 diabetes (T2D) inadequately controlled with oral antidiabetic drugs (OADs) initiating these regimens have been conducted, real-world data are lacking. This study describes the characteristics of patients initiating these regimens in routine clinical practice and identifies the course and outcomes of therapy in the year following initiation. METHODS: Adults with T2D initiating BB or premixed regimens following OAD therapies held in a Japanese electronic medical record database were identified (2010-2019). Subcohorts were determined by treatment changes during ≤ 12 months of follow-up (no change, intensified, switched, discontinued). Outcomes included change in glycated haemoglobin levels (HbA1c), probability of first reaching HbA1c < 7% (stratified by baseline OAD number, HbA1c and age), and hypoglycaemia incidence. RESULTS: The main cohorts comprised 1315 BB and 1195 premixed therapy initiators. Most individuals (67.9%) initiated BB as inpatients; 50.8% switched at a mean of 47.6 days. Mean HbA1c lowering was - 2.5% for BB and - 1.4% for premixed regimens (no change cohorts). Overall, a greater proportion achieved HbA1c < 7% if they were (at baseline) taking fewer OADs, in a lower HbA1c category, and aged ≥ 65 years. Hypoglycaemia incidence (< 70 mg/dl) was higher with BB than premixed regimens and lower in patients aged < 65 years. CONCLUSION: Greater HbA1c reductions, but a higher incidence of hypoglycaemia, were reported with BB versus premixed regimens, while both cohorts demonstrated clinically meaningful reductions in HbA1c during follow-up. After initiation, most premixed regimens remained unchanged, whereas switches from BB to less intensive regimens were numerous, in accordance with the use of BB for a limited duration to improve FPG and PPG control.