952-P: What Happens When People Don’t Bolus for Extended Periods of Time while Using the t:slim X2 with Control-IQ Technology?

Objective: The t:slim X2 with Control-IQ technology (CIQ) predicts future hyperglycemia and delivers automatic correction boluses to help improve time-in-range (TIR, 70-180 mg/dl). This is thought to help improve glycemia when users do not initiate boluses for meals. The purpose of this analysis is to determine glycemic results in users who do not bolus for prolonged periods of time.

Methods: Data were analyzed from the Tandem Diabetes Care t:connect database for CIQ users from January 2020 to December 2023. Users were included for analysis if they had a minimum of 7/ 14/ 30/ 182 days without a carbohydrate bolus and ≤ 1 manual bolus. Time in range (TIR) and time-below-range (TBR, <70 mg/dl) were analyzed on days without bolusing compared to days with user-initiated boluses.

Results: Out of 291,769 CIQ users, 28,790 (10% users) had used the system for 7+ consecutive days without bolusing. The average number of days without boluses was 61 per user. There were a total of 1,728,304 days without boluses in the database. 27,688 users had periods of 7-13 consecutive days without user-initiated boluses. 11,127 users had periods of 14-29 consecutive days without user-initiated boluses. 3,813 users had periods of 30-181 consecutive days without user-initiated boluses. And 102 users had periods of more than 6 months of consecutive days without user-initiated boluses. On days without boluses, median TIR was 62% (IQR 50-74%) in all four groups, whereas median TIR for days with boluses was 57%-60% (IQR 46-70%). The TBR was less than 0.6% for both days without boluses and days with boluses.

Conclusion: Users of Control-IQ technology who do not bolus for extended periods of time have slightly higher TIR on days when they do not bolus compared to days when they take manual boluses, with no increase in hypoglycemia. This is likely due to myriad reasons, including that the CIQ system can attenuate hyperglycemia enough to be acceptable for a subset of users who struggle with consistent bolusing.