With or Without Residual C-Peptide, Patients with Type 2 Diabetes Realize Glycemic Benefits from Real-Time Continuous Glucose Monitoring

Real-time continuous glucose monitoring (RT-CGM) is superior to blood glucose monitoring (BGM) for adults with insulin-treated type 2 diabetes (T2D); however, the utility of C-peptide levels for predicting the magnitude of the glycemic benefits is controversial. Data were from a subset of 147 participants in the MOBILE study who were treated with basal-only insulin and who had baseline C-peptide levels >= 0.5 ng/mL. Participants were randomized to treatment with either RT-CGM (n = 100) or BGM (n = 47). Between-group differences in hemoglobin A1c (HbA1c) and time in range (TIR) changes were assessed. The between-group difference in HbA1c favored the RT-CGM group (by 0.58 percentage points, P = 0.004 at 3 months and by 0.42 percentage points, P = 0.04 at 8 months). TIR was 16% higher, and time >180 mg/dL was 16% lower, in the RT-CGM group at 8 months (P = 0.002 for each). In T2D managed with basal insulin, RT-CGM benefits occur for those with residual insulin secretory capacity. Clinical Trial Identifier: NCT03566693