Improvement in Glucometric Outcomes After Control-IQ Initiation in Pediatric and Adolescent Type 1 Diabetes Patients: The Impact of Basal Time in Range

The development of closed-loop systems represents an evolutionary advance in the management of patients with type 1 diabetes (T1D). This study aimed to analyze the impact of the Control-IQ advanced hybrid closed-loop (AHCL) system on glucometric outcomes in a pediatric and adolescent population with T1D, comparing results with baseline values and assessing the influence of baseline Time in Range (TIR) on glycemic control in children under 6 years old over a 12-month period. A 12-month prospective analysis was conducted in 26 patients with T1D (aged 2-15 years) initiating the Control-IQ system. Glucometric variables were assessed at baseline (before system implementation) and at 1, 3, 6, and 12 months post-implementation. A subgroup analysis was performed in patients under 6 years old (<i>n</i> = 13), to evaluate the relationship between basal TIR and glucometric outcomes during the follow-up. TIR increased significantly from 62.04% at baseline to 72.50% at one month (from 57.58% to 66.18% in patients under 6 years), with this improvement sustained throughout follow-up. Time in hyperglycemia 180-250 mg/dL (TAR1) also showed significant improvement (26.84% to 17.40% at one month; 28.66% to 20.09% in patients under 6 years), with significant reductions maintained at all timepoints. Stratification according to the proportion of patients meeting consensus targets revealed significant improvements in TIR and TAR2 at 1 and 12 months in the overall cohort, though not in the under-6 subgroup. Significant differences in TIR and coefficient of variation (CV) were observed based on baseline TIR categorization (<70% vs. ≥70%). Our study revealed a significant enhancement in TIR and time spent in hyperglycemia from the first month after the implementation of the closed-loop system, which was maintained at 12 months, in both the overall cohort and the subgroup under 6 years old. In this younger subgroup, baseline TIR predicted subsequent glycemic control, with higher baseline TIR associated with better long-term outcomes in both TIR and CV.