The Longer, the Better: Continuous Glucose Monitoring Use for ≥90% Is Superior to 70%-89% in Achieving Tighter Glycemic Outcomes in Children with Type 1 Diabetes.

Objective: The recommended threshold for the time spent on continuous glucose monitoring (CGM) is established at 70%. However, glucose outcomes in children with type 1 diabetes (CwD) using CGM for a different proportion of time within this threshold have not been evaluated yet. The study aims to compare glycemic parameters among CwD who spent 70%-89% and ≥90% on CGM using the population-wide data from the Czech national pediatric diabetes registry ČENDA. Methods: CwD aged <19 years who used real-time CGM >70% of the time and did not change the type of therapy throughout the year 2023 were included and divided into two groups based on the time they spent on CGM-70%-89% versus ≥90%. HbA1c, times in standard glycemic ranges, mean glucose, and coefficient of variability (CV) were compared between the groups and by treatment modalities. Results: Data from 1977 CwD (1035 males and 942 females) were evaluated. Among them, 404 participants (20.4%) used CGM 70%-89% of the time, and 1573 participants (79.6%) ≥90% of the time. Compared with the 70-89% group, the ≥90% CGM users achieved significantly lower HbA1c levels (51 mmol/mol, 6.8% vs. 58 mmol/mol, 7.4%, P < 0.001), higher time in range (72% vs. 60%, P < 0.001), and lower mean glucose and CV (8.1 mmol/L, 146 mg/dL vs. 9.1 mmol/L, 164 mg/dL and 37% vs. 40%, respectively, both P < 0.001). Analogous results were seen irrespective of the treatment modality. The differences persisted after propensity score adjustment. Conclusion: CGM use for ≥90% is associated with tighter glycemic control compared with 70%-89% use. Therefore, it is essential to motivate CwD to use CGM for the longest possible time and search for suitable options to overcome barriers in uninterrupted CGM monitoring.