REVISED_Supplemental_material_6-21-2021.pdf (536.23 kB)

Advanced Closed-Loop Control System Improves Postprandial Glycemic Control Compared With a Hybrid Closed-Loop System Following Unannounced Meal

Download (536.23 kB)
figure
posted on 16.08.2021, 10:48 by Jose Garcia-Tirado, Jenny L. Diaz, Rebeca Esquivel-Zuniga, Chaitanya L. K. Koravi, John P. Corbett, Martha Dawson, Christian Wakeman, Charlotte L. Barnett, Mary C. Oliveri, Helen Myers, Katie Krauthause, Marc D. Breton, Mark D. DeBoer
Objective: Meals are a major hurdle to glycemic control in type 1 diabetes (T1D). Our objective was to test a fully-automated closed-loop control (CLC) system in the absence of announcement of carbohydrate ingestion among adolescents with T1D, who are known to commonly omit meal announcement.

Research Design and Methods: Eighteen adolescents with T1D (age 15.6±1.7 years; HbA1c 7.4%±1.5; 9F/9M) participated in a randomized crossover clinical trial comparing our legacy hybrid CLC system (USS-Virginia) with a novel fully-automated CLC system (RocketAP), during two 46h supervised admissions (each with one announced and one unannounced dinner), following 2 weeks of data collection. Primary outcome was the percent time-in-range 70-180mg/dL (TIR) following the unannounced meal, with secondary outcomes related to additional CGM-based metrics.

Results: Both TIR and time-in-tight-range 70-140mg/dL (TTR) were significantly higher using RocketAP than using USS-Virginia during the 6h following the unannounced meal (83% [64-93] vs. 53% [40-71]; p=0.004 and 49% [41-59] vs. 27% [22-36]; p=0.002, respectively), primarily driven by reduced time-above-range (TAR >180mg/dL 17% [1.3-34] vs. 47% [28-60]), with no increase in time-below-range (TBR <70mg/dL 0% median for both). RocketAP also improved control following the announced meal (mean difference TBR: -0.7%, TIR: +7%, TTR: +6%), overall (TIR: +5%, TAR: -5%, TTR: +8%), and overnight (TIR: +7%, TTR: +19%, TAR: -5%). RocketAP delivered less insulin overall (78±23U vs. 85±20U, p=0.01)

Conclusions: A new fully-automated CLC system with automatic prandial dosing was proven to be safe and feasible and outperformed our legacy USS-Virginia in an adolescent population with and without meal announcement.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This project was funded by generous grants from the University of Virginia’s LaunchPad Program (to MDD and MDB) and the Strategic Investment Fund project “Precision Individualized Medicine for Diabetes (PriMeD).”

History