The Effect of Discontinuing Continuous Glucose Monitoring in Adults With Type 2 Diabetes Treated With Basal Insulin

Abstract

Objective: To explore the effect of discontinuing continuous glucose monitoring (CGM) after 8 months of CGM use in adults with type 2 diabetes treated with basal without bolus insulin.

Research design and methods: This multicenter trial had an initial randomization to either real-time CGM or blood glucose monitoring (BGM) for 8 months followed by 6 months in which the BGM group continued to use BGM (n = 57) and the CGM group was randomly reassigned either to continue CGM (n = 53) or discontinue CGM with resumption of BGM for glucose monitoring (n = 53).

Results: In the group that discontinued CGM, mean time in range (TIR) 70-180 mg/dL, which improved from 38% before initiating CGM to 62% after 8 months of CGM, decreased after discontinuing CGM to 50% at 14 months (mean change from 8 to 14 months -12% [95% CI -21% to -3%], P = 0.01). In the group that continued CGM use, little change was found in TIR from 8 to 14 months (baseline 44%, 8 months 56%, 14 months 57%, mean change from 8 to 14 months 1% [95% CI -11% to 12%], P = 0.89). Comparing the two groups at 14 months, the adjusted treatment group difference in mean TIR was -6% (95% CI -16% to 4%, P = 0.20).

Conclusions: In adults with type 2 diabetes treated with basal insulin who had been using real-time CGM for 8 months, discontinuing CGM resulted in a loss of about one-half of the initial gain in TIR that had been achieved during CGM use.

Trial registration: ClinicalTrials.gov NCT03566693.

Figure 1

Glycemic outcomes by treatment and visit. Mean TIR 70–180 mg/dL (A) and mean HbA_1c (B) at baseline, month 8, and month 14. The continue CGM group showed CGM for the full 14 months, and the BGM group used BGM for the full 14 months. The discontinue CGM group used CGM through month 8 and then discontinued CGM and used BGM through month 14. Error bars represent 95% CIs.

Figure 2

Twenty-four-hour plots of phase 2 TIR at baseline, month 8, and month 14 for each treatment group. A plot of TIR 70–180 mg/dL is shown for the discontinue CGM group (A), continue CGM group (B), and BGM group (C) at baseline, month 8, and month 14 according to time of day. Symbols denote the hourly median values for TIR.