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.

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. 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. 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%, < 0.001), higher time in range (72% vs. 60%, < 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 < 0.001). Analogous results were seen irrespective of the treatment modality. The differences persisted after propensity score adjustment. 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.