Abstract
Disclosure: S.J. Russell: Beta Bionics. R.R. Selagamsetty,: Beta Bionics. C.S. Balliro: Beta Bionics. E. Damiano: Beta Bionics. Background: The iLet bionic pancreas is an automated insulin delivery system that is initialized with only body weight. The only user input is meal announcements without carbohydrate counting. Meals and snacks are announced as a type (Breakfast, Lunch, or Dinner) and a relative size for that type (Usual for me, More, or Less). The iLet then autonomously determines the size of meal doses. All basal and correction insulin is determined autonomously by the iLet, which adapts continuously to changing insulin needs. The only input from the health care provider is the glucose target profile. Objective: The objective of this analysis was to assess the association between the number of meals announced by the user per day on one hand, and the frequency of user interaction with the iLet (determine by number of swipes to unlock the iLet) on the other, on continuous glucose monitoring (CGM) outcomes during real-world use of the iLet bionic pancreas by adults (≥18 years of age) during the first 18 months after FDA clearance. This analysis was undertaken with the goal of providing users and health care providers information they can use to obtain the best glycemic control from the iLet. Methods: Commercial users of the iLet who had a pre-iLet HbA1c value available and at least 3 weeks of iLet data in the cloud (n=5,987) were included in the analysis. Glucose management indicator (GMI) values and percentage of time in ranges (%70-180 mg/dl, %<70 mg/dl, and %<54 mg/dl) were calculated from all available CGM data. Users were classified according to the average number of meal announcements per day (MPD; from <0.5 to ≥4.5 per day in 0.5 meal increments) and separately according to the number of swipes to unlock the (STU; ≤4, 4-<13, and ≥13 swipes to unlock per day). Results: Mean baseline HbA1c was 8.6%; mean iLet GMI was 7.2%. Groups with <2.5 MPD had higher GMI and lower %70-180 mg/dl than those with ≥2.5 MPD. Groups with ≥2.5 to <4.5 MPD all had similar outcomes, with lower GMI and higher %70-180 mg/dl than groups with <2.5 MDP. There was little difference in %<70 mg/dl and %<54 mg/dl from <0.5 to <4.5 MPD. The ≥4.5 MPD group had lower GMI and higher %70-180 mg/dl than others, but it also had higher %<70 mg/dl and %<54 mg/dl. GMI and %<54 mg/dl was similar for all levels of STU. Higher STU was associated with higher %70-180 mg/dl and higher %<70 mg/dl. Discussion/Conclusion: In users of the iLet bionic pancreas the best outcomes were achieved by those announcing 2.5 to <4.5 MPD. This may correspond to typical numbers of meals and snacks consumed by users. Announcement of ≥4.5 MPD was associated with lower GMI and higher %70-180 mg/dl, but also higher %<54 mg/dl. Users announcing ≥4.5 MPD may be announcing “ghost” meals to obtain correction insulin, which risks “stacking” on top of iLet-determined correction doses and may lead to increased hypoglycemia. Higher STU was associated with higher %70-180 mg/dl and %<70 mg/dl but little difference in GMI and %<54 mg/dl. Presentation: Monday, July 14, 2025