A Simple Meal Bolus Strategy is Effective in Adolescents and Young Adults with Type 1 Diabetes on Multiple Automated Insulin Delivery Systems

Abstract

Background:

Carbohydrate counting (CC) is challenging and may be a barrier to automated insulin delivery (AID) use. Given the ability of AID to modulate insulin delivery, a simpler meal bolus strategy may be adequate for glycemic management.

Methods:

Participants aged 14–26 using AID were enrolled in a randomized crossover trial comparing glycemic management using simple boluses versus CC for 4 weeks each. Before the simple period, participants were educated to enter a set carbohydrate amount for a small (30 g), medium (60 g), or large (90 g) meal, and carbohydrate ratios were standardized. Glycemic outcomes were compared between study periods. We hypothesized that time in range (TIR) 70–180 mg/dL would not be inferior by more than 5% during the simple period compared with the CC period. Other measures of glycemia were compared using paired t-tests.

Results:

Among 31 participants (17.4 years; 51.6% female; type 1 diabetes duration [T1D_Dur.] 8.3 years; baseline TIR 64.1%), TIR with simple meal boluses was not inferior to TIR with CC (simple TIR 64.2%, CC TIR 66.0%, difference −1.8%, lower limit of 95% confidence interval: −3.9, P = 0.008 indicating noninferiority at a margin of Δ = 5). There were no differences in % time >250 mg/dL (difference 1.2%, P = 0.3) and % time <70 mg/dL (difference −0.02%, P = 0.9). After the study, 31.3% of participants preferred CC, 40.6% preferred simple boluses, and 28.1% preferred their prestudy method.

Conclusion:

Precise CC may be an unnecessary burden for T1D adolescents using AID, and requiring it could impact success with or access to these systems. Using a simple meal bolus strategy is one option to reduce burden without significant impact on glycemic outcomes (Clinical Trials Registration number- NCT06575790).