Randomized, Crossover Trial of Control-IQ Technology with a Lower Treatment Range and a Modified Meal Bolus Module in Adults, Adolescents, Children, and Preschoolers with Varying Levels of Baseline Glycemic Control

<b><i>Objective:</i></b> We evaluated a modified version of Control-IQ technology with a lower treatment range and a modified meal bolus module in adults, adolescents, children, and preschoolers with type 1 diabetes in a multicenter, randomized, and crossover trial. <b><i>Research Design and Methods:</i></b> After a 2-week run-in with Control-IQ technology v1.5, the modified system was evaluated for 2 weeks using treatment range of 112.5-160 mg/dL (standard range [SR]), and for 2 weeks using lower treatment range of 90-130 mg/dL (lower range, LR), at home in random order. Two late bolus meal challenges were performed in each 2-week period, bolusing 45 min after meals with and without a new late bolus feature. <b><i>Results:</i></b> Overall, 72 participants aged 3-57 years completed the study. There were no diabetic ketoacidosis or severe hypoglycemia events. All meal challenges were completed safely. Time in range (TIR) 70-180 mg/dL improved the most with LR to 68.0% (+3.1%, <i>P</i> < 0.001, for LR vs. run-in and +2.1%, <i>P</i> < 0.001, for LR vs. SR). Similar improvements were observed for time in tight range (TITR) 70-140 mg/dL (+3.3%, <i>P</i> < 0.001, for LR vs. run-in and +4.0%, <i>P</i> < 0.001, for LR vs. SR), time >180 mg/dL, and mean glucose. Participants with lower baseline hemoglobin A1c (HbA1c) achieved the highest TIR and TITR with LR use, while the greatest improvements in TIR and TITR were evident in those with higher baseline HbA1c. <b><i>Conclusions:</i></b> The lower treatment range and late bolus feature of the modified Control-IQ system were safe for use in all age-groups. TIR and TITR improved with LR regardless of baseline HbA1c.