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%; 9 females/9 males) participated in a randomized crossover clinical trial comparing our legacy hybrid CLC system (Unified Safety System Virginia [USS]-Virginia) with a novel fully automated CLC system (RocketAP) during two 46-h supervised admissions (each with one announced and one unannounced dinner), following 2 weeks of data collection. Primary outcome was the percentage time-in-range 70–180 mg/dL (TIR) following the unannounced meal, with secondary outcomes related to additional continuous glucose monitoring-based metrics. RESULTS Both TIR and time-in-tight-range 70–140 mg/dL (TTR) were significantly higher using RocketAP than using USS-Virginia during the 6 h following the unannounced meal (83% [interquartile range 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 >180 mg/dL: 17% [1.3–34] vs. 47% [28–60]), with no increase in time-below-range (TBR <70 mg/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 ± 23 units vs. 85 ± 20 units, 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.

OBJECTIVE Meals are a consistent challenge to glycemic control in type 1 diabetes (T1D). Our objective was to assess the glycemic impact of meal anticipation within a fully automated insulin delivery (AID) system among adults with T1D. RESEARCH DESIGN AND METHODS We report the results of a randomized crossover clinical trial comparing three modalities of AID systems: hybrid closed loop (HCL), full closed loop (FCL), and full closed loop with meal anticipation (FCL+). Modalities were tested during three supervised 24-h admissions, where breakfast, lunch, and dinner were consumed per participant’s home schedule, at a fixed time, and with a 1.5-h delay, respectively. Primary outcome was the percent time in range 70–180 mg/dL (TIR) during the breakfast postprandial period for FCL+ versus FCL. RESULTS Thirty-five adults with T1D (age 44.5 ± 15.4 years; HbA1c 6.7 ± 0.9%; n = 23 women and n = 12 men) were randomly assigned. TIR for the 5-h period after breakfast was 75 ± 23%, 58 ± 21%, and 63 ± 19% for HCL, FCL, and FCL+, respectively, with no significant difference between FCL+ and FCL. For the 2 h before dinner, time below range (TBR) was similar for FCL and FCL+. For the 5-h period after dinner, TIR was similar for FCL+ and FCL (71 ± 34% vs. 72 ± 29%; P = 1.0), whereas TBR was reduced in FCL+ (median 0% [0–0%] vs. 0% [0–0.8%]; P = 0.03). Overall, 24-h control for HCL, FCL, and FCL+ was 86 ± 10%, 77 ± 11%, and 77 ± 12%, respectively. CONCLUSIONS Although postprandial control remained optimal with hybrid AID, both fully AID solutions offered overall TIR >70% with similar or lower exposure to hypoglycemia. Anticipation did not significantly improve postprandial control in AID systems but also did not increase hypoglycemic risk when meals were delayed.

<b>Objective:</b> 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. <p><b>Research Design and Methods: </b>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.</p> <p><b>Results: </b> 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)</p> <p><b>Conclusions:</b> 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.</p>

<b>Objective:</b> 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. <p><b>Research Design and Methods: </b>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.</p> <p><b>Results: </b> 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)</p> <p><b>Conclusions:</b> 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.</p>

<b>Objective:</b> 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. <p><b>Research Design and Methods: </b>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.</p> <p><b>Results: </b> 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)</p> <p><b>Conclusions:</b> 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.</p>