Intermittently Scanned Continuous Glucose Monitoring for Type 1 Diabetes

Abstract

Background The benefits of intermittently-scanned continuous glucose monitoring with optional alarms (isCGM) for people with Type 1 diabetes (T1D) and high glycated hemoglobin levels are unknown. Methods In this multicenter, parallel-design, randomized controlled trial, 156 people with T1D and glycated hemoglobin values between 7.5% and 11.0% with mean (SD) age 43.5 (14.9) years, diabetes duration 21.1 (12.6) years, 44% women, were allocated (1:1) to isCGM (n=78) or self-monitoring of blood glucose with finger sticks (SMBG, n=78). The primary outcome was glycated hemoglobin at 24 weeks analyzed according to ‘intention to treat.’ Key secondary outcomes were sensor metrics, participant-reported outcome measures, and safety. Results The mean (SD) baseline glycated hemoglobin (%) was 8.7 (0.9) in the isCGM group and 8.5 (0.8) in the SMBG group, decreased to 7.9 (0.8) vs. 8.3 (0.9), respectively, at 24 weeks (adjusted mean difference -0.5, 95% confidence interval [CI] -0.7 to -0.3; p<0.001]. The time per day with the glucose level in the target range was 9.0 (95% CI 4.7 to 13.3) percentage points or 130 (95% CI 68 to 192) minutes higher, the time spent in hypoglycemia (<70mg/dl) was 3.0 (95% CI 1.4 to 4.5) percentage points or 43 (95% CI 20 to 65) minutes lower. The Diabetes Treatment Satisfaction Questionnaire score was 7.0 (95% CI 5.2 to 8.7) points higher in the isCGM group. Two participants experienced severe hypoglycemia in the SMBG group while one participant in the isCGM group experienced skin reaction to sensor. Conclusions Among adults with T1D and high glycated hemoglobin levels, use of isCGM with optional alarms resulted in significantly lower glycated hemoglobin levels as compared with SMBG.