Glycemic outcomes of use of CLC versus plgs in type 1 diabetes: A randomized controlled trial

Abstract

OBJECTIVE Limitedinformation is available about glycemic outcomes with a closed-loop control (CLC) system compared with a predictive low-glucose suspend (PLGS) system. RESEARCH DESIGN AND METHODS After 6 months of use of a CLC system in a randomized trial, 109 participants with type 1 diabetes (age range, 14–72 years; mean HbA1c, 7.1% [54 mmol/mol]) were randomly assigned to CLC (N 5 54, Control-IQ) or PLGS (N 5 55, Basal-IQ) groups for 3 months. The primary outcome was continuous glucose monitor (CGM)-measured time in range (TIR) for 70–180 mg/dL. Baseline CGM metrics were computed from the last 3 months of the preceding study. RESULTS All 109 participants completed the study. Mean 6 SD TIR was 71.1 6 11.2% at baseline and 67.6 6 12.6% using intention-to-treat analysis (69.1 6 12.2% using per-protocol analysis excluding periods of study-wide suspension of device use) over 13 weeks on CLC vs. 70.0 6 13.6% and 60.4 6 17.1% on PLGS (difference 5 5.9%; 95% CI 3.6%, 8.3%; P < 0.001). Time >180 mg/dL was lower in the CLC group than PLGS group (difference 526.0%; 95% CI 28.4%, 23.7%; P < 0.001) while time <54 mg/dL was similar (0.04%; 95% CI 20.05%, 0.13%; P 5 0.41). HbA1c after 13 weeks was lower on CLC than PLGS (7.2% [55 mmol/mol] vs. 7.5% [56 mmol/ mol], difference 20.34% [23.7 mmol/mol]; 95% CI 20.57% [26.2 mmol/mol], 20.11% [1.2 mmol/mol]; P 5 0.0035). CONCLUSIONS Following 6 months of CLC, switching to PLGS reduced TIR and increased HbA1c toward their pre-CLC values, while hypoglycemia remained similarly reduced with both CLC and PLGS.