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

<b>Objective: </b>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. <p><b>Research Design and Methods:</b> Multi-center trial with 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 re-randomized either to continue CGM (N=53) or discontinue CGM with resumption of BGM for glucose monitoring (N=53). </p> <p><b>Results: </b>In the group that discontinued CGM, mean time in range 70-180 mg/dL (TIR), which improved from 38% prior to 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 continuing CGM, there was little change in TIR from 8 to 14 months (baseline 44%, 8 months 56%, 14 months 57%; mean change 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).</p> <p><b>Conclusions: </b>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 half of the initial gain in TIR that had been achieved during CGM use.</p>