Rapid improvements in glycemic management with use of continuous glucose monitoring in adults with type 2 diabetes treated with basal insulin: 3-month analysis of the MOBILE study

Abstract

Introduction: This analysis investigated whether use of real-time continuous glucose monitoring (CGM) compared with blood glucose monitoring (BGM) results in rapidly improved glycemic management in adults with type 2 diabetes (T2D) treated with basal insulin.

Research design and methods: Using data from the MOBILE study where adults (n=175) with T2D treated with basal insulin without prandial insulin were randomized (2:1) to either CGM (n=116) or BGM (n=59), the treatment effect on glycemic management was determined over 3 months. The main outcome was a between-group difference in hemoglobin A_1c (HbA_1c) at 3 months adjusted for baseline value. Other outcomes included changes in CGM-derived glucose metrics and hypoglycemic events.

Results: After 3 months, there was a greater reduction from baseline in mean HbA_1c in the CGM group compared with the BGM group, from 9.1±1.0% (76±11 mmol/mol) to 8.0±1.2% (64±13 mmol/mol) in the CGM group and from 9.0±0.9% (75±10 mmol/mol) to 8.5±1.5% (69±16 mmol/mol) in the BGM group (adjusted difference, -0.6% (95% CI -0.9% to -0.3%); -6.6 mmol/mol (95% CI -10.2 to -2.9), p<0.001). Mean time spent in range 70-180 mg/dL (3.9-10.0 mmol/L) increased significantly more in the CGM group than the BGM group (adjusted difference, +9.3% (95% CI 2.1% to 16.4%), p<0.001). There also was a greater reduction in mean time >250 mg/dL (>13.9 mmol/L) with CGM (adjusted difference, -5.8% (95% CI -10.4% to -1.2%), p<0.001) without an increase in time <70 mg/dL (<3.9 mmol/L). Mean weekly hypoglycemic event rate was lower with CGM than BGM (adjusted difference, -0.2 events per week (95% CI -0.4 to -0.1), p<0.001). Further, in the CGM group, significant improvements in CGM metrics were observed during the first 7 days of CGM use.

Conclusions: In adults with basal insulin-treated T2D, use of CGM compared with BGM resulted in rapidly improved glycemic management, with a substantial reduction in HbA_1c over 3 months.

Trial registration number: NCT03566693.

Keywords: Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Glycated Hemoglobin A.

Figure 1. CGM-derived times (%) in glucose ranges at baseline and 3 months. Data may not total 100% due to rounding. p values indicate between-group difference at 3 months (model adjusted mean difference). At the bottom of each bar, the data label on the left of the slash denotes the time <70 mg/dL (<3.9 mmol/L) and the data label on the right denotes the time <54 mg/dL (3.0 mmol/L). BGM, blood glucose monitoring; CGM, continuous glucose monitoring.

Figure 2. Weekly CGM-derived metrics for the CGM group. (A) shows estimated change from baseline (%) using mixed models with repeated measurements and (B) shows absolute weekly values (%). Data in (B) may not total 100% due to rounding. In (B), at the bottom of each bar, the data label on the left of the slash denotes the time <70 mg/dL (<3.9 mmol/L) and the data label on the right denotes the time <54 mg/dL (3.0 mmol/L). CGM, continuous glucose monitoring.