Glycemic Outcomes of Use of CLC Versus PLGS in Type 1 Diabetes: A Randomized Controlled Trial
Authors: Brown Sue A. , Beck Roy W. , Raghinaru Dan , Buckingham Bruce A. , Laffel Lori M. , Wadwa R. Paul , Kudva Yogish C. , Levy Carol J. , Pinsker Jordan E. , Dassau Eyal , Doyle Francis J. , Ambler-Osborn Louise , Anderson Stacey M. , Church Mei Mei , Ekhlaspour Laya , Forlenza Gregory P. , Levister Camilla , Simha Vinaya , Breton Marc D. , Kollman Craig , Lum John W. , Kovatchev Boris P. ,   iDCL Trial Research Group, Kovatchev Boris , Anderson Stacey , Emory Emma , Voelmle Mary , Conshafter Katie , Morris Kim , Oliveri Mary , Gondor-Fredrick Linda , Mitchell Harry , Calvo Kayla , Wakeman Christian , Breton Marc , Laffel Lori , Isganaitis Elvira , Ambler-Osborn Louise , Flint Emily , Kim Kenny , Roethke Lindsay , Pinsker Jordan , Church Mei Mei , Andre Camille , Piper Molly , Levy Carol , Lam David , O’Malley Grenye , Levister Camilla , Ogyaadu Selassie , Lovett Jessica , Kudva Yogish C. , Simha Vinaya , Dadlani Vikash , McCrady-Spitzer Shelly , Reid Corey , Kumari Kanchan , Wadwa R. Paul , Forlenza Greg , Alonso G. Todd , Slover Robert , Jost Emily , Messer Laurel , Berget Cari , Towers Lindsey , Rossick-Solis Alex , Buckingham Bruce , Ekhlaspour Laya , Jacobson Tali , Town Marissa , Tabatabai Ideen , Keller Jordan , Salas Evalina , Doyle Francis , Dassau Eyal , Lum John , Beck Roy , Passman Samantha , Campos Tiffany , Raghinaru Dan , Kollman Craig , Murphy Carlos , Patibandla Nandan , Borgman Sarah , Arreza-Rubin Guillermo , Eggerman Thomas , Green Neal , Kovatchev Boris , Brown Sue , Anderson Stacey , Breton Marc , Laffel Lori , Pinsker Jordan , Levy Carol , Kudva Yogish C. , Wadwa R. Paul , Buckingham Bruce , Doyle III Francis , Renard Eric , Cobelli Claudio , Reznik Yves , Arreza-Rubin Guillermo , Lum John , Beck Roy , Janicek Robert , Gabrielson Deanna , Belle Steven H. , Castle Jessica , Green Jennifer , Legault Laurent , Willi Steven M. , Wysham Carol , Eggerman Thomas 
Published: May 2020

OBJECTIVE

Limited information 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 = 54, Control-IQ) or PLGS (N = 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 ± SD TIR was 71.1 ± 11.2% at baseline and 67.6 ± 12.6% using intention-to-treat analysis (69.1 ± 12.2% using per-protocol analysis excluding periods of study-wide suspension of device use) over 13 weeks on CLC vs. 70.0 ± 13.6% and 60.4 ± 17.1% on PLGS (difference = 5.9%; 95% CI 3.6%, 8.3%; P &lt; 0.001). Time &gt;180 mg/dL was lower in the CLC group than PLGS group (difference = −6.0%; 95% CI −8.4%, −3.7%; P &lt; 0.001) while time &lt;54 mg/dL was similar (0.04%; 95% CI −0.05%, 0.13%; P = 0.41). HbA1c after 13 weeks was lower on CLC than PLGS (7.2% [55 mmol/mol] vs. 7.5% [56 mmol/mol], difference −0.34% [−3.7 mmol/mol]; 95% CI −0.57% [−6.2 mmol/mol], −0.11% [1.2 mmol/mol]; P = 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.