Aiming for the Best Glycemic Control Beyond Time in Range: Time in Tight Range as a new CGM Metric in Children and Adolescents with Type 1 Diabetes using Different Treatment Modalities

Introduction: To evaluate time in tight range (TITR) 70-140 mg/dL (3.9- 7.8 mmol/L), its correlation with standard continuous glucose monitoring (CGM) metrics and the clinical variables that possibly have a substantial impact on its value, in a large cohort of pediatric subjects using different treatment strategies. Material and methods: A total of 854 children and adolescents with type 1 diabetes were consecutively recruited in this real-world, dual-center, cross-sectional study. Participants were categorized into four treatment groups (multiple daily injections + real-time CGM, multiple daily injections + intermittently scanned CGM, sensor augmented pump, and hybrid closed loop (HCL)). Demographical and clinical data, including CGM data, were collected and analyzed. Results: The overall study population exhibited an average TITR of 36.4±12.8%. HCL users showed higher TITR levels compared to the other treatment groups (p<0.001). A time in range (TIR) cut-off value of 71.9% identified subjects achieving a TITR≥50% (AUC 0.98; 95%CI 0.97-0.99, p<0.001), and a strong positive correlation between these two metrics was observed (r=0.95, p<0.001). An increase in TIR of 1% was associated with 1.84 (R2 Nagelkerke=0.35, p<0.001) increased likelihood of achieving TITR≥50%. Use of HCL systems (B=7.78; p<0.001), disease duration (B=-0.26, p=0.006), coefficient of variation (B=-0.30, p=0.004), and glycated haemoglobin (B=-8.82; p<0.001) emerged as significant predictors of TITR levels. Conclusions: Our study highlights that most children and adolescents with type 1 diabetes present TITR levels below 50%, except those using HCL. Tailored interventions and strategies should be implemented to increase TITR.