Longitudinal Continuous Glucose Monitoring Study in Young Children With Presymptomatic Type 1 Diabetes Followed in the Environmental Determinants of Islet Autoimmunity (ENDIA) At-Risk Cohort Study

Abstract

Objective: To characterize longitudinal continuous glucose monitoring (CGM) data in young children with presymptomatic type 1 diabetes.

Research design and methods: Between 2021 and 2024, children in the Australian ENDIA study with persistent multiple islet autoimmunity underwent blinded CGM assessments every 3-6 months. CGM-derived metrics (SD sensor glucose, coefficient of variation, mean sensor glucose, and percent CGM time >7.8 mmol/L [140 mg/dL]) were determined for each child by time from islet autoantibody detection.

Results: A total of 178 CGM assessments were analyzed for 36 children (median [Q1, Q3] age at first assessment 4.5 [3.5, 6.0] years) who underwent a median of 5.5 (2.0, 7.0) assessments of 11 (9, 15) days duration each. High within-person variability was observed in serial CGM metrics, including percent CGM time >7.8 mmol/L (140 mg/dL) (intraclass correlation coefficient 0.30).

Conclusions: Further research is needed to inform interpretation of CGM-derived metrics in young children with presymptomatic type 1 diabetes.

Graphical abstract

Figure 1

Percent CGM time >7.8 mmol/L (140 mg/dL) (A), SDSGL (B), CV SGL (C), and mean SGL (D) by time since islet autoantibody detection and progressor status at end of the study period. Each line represents an individual participant. Time from last CGM assessment to clinical diagnosis and insulin commencement for progressors was 0.2 months (pink), 0.6 months (orange), 1.9 months (light purple), 3.3 months (dark green), 3.6 months (brown and blue), 7.9 months (dark purple), and 13.8 months (light green).

Figure 2

HbA_1c percent (A) and mean 3:00–5:00 a.m. sensor glucose (B) by time since islet autoantibody detection and progression status at the end of the study period. Each line represents an individual participant. Time from last CGM assessment to clinical diagnosis and insulin commencement for progressors was 0.2 months (pink), 0.6 months (orange), 1.9 months (light purple), 3.3 months (dark green), 3.6 months (brown and blue), 7.9 months (dark purple), and 13.8 months (light green).