CGM Metrics Predict Imminent Progression to Type 1 Diabetes: Autoimmunity Screening for Kids (ASK) Study

Objective: Children identified with stage 1 type 1 diabetes are at high risk for progressing to stage 3 (clinical) diabetes and require accurate monitoring. Our aim was to establish CGM metrics that could predict imminent progression to diabetes.

Methods: In the Autoimmunity Screening for Kids study, 91 children persistently islet autoantibody positive (median age 11.5 y, 48% non-Hispanic White, 57% female) with a baseline CGM were followed for development of diabetes for a median of 6 (range:0.2-34) months. Of these, 16 (18%) progressed to clinical diabetes in a median of 4.5 (range:0.4-29 months.

Results: Compared to non-progressors, progressors had significantly higher average sensor glucose (119 vs 105 mg/dL) and increased glycemic variability: SD 27 vs 16, CV 21 vs 15, MODD 24 vs 16 and MAGE 43 vs 26. Progressors spent 21% of time above 140 mg/dl (TA140) and 8% above 160 mg/dl, compared to 3% and 1%, respectively, for non-progressors. In survival analyses, the risk of progression to diabetes in one year was 80% in those with TA140 >10%; in contrast, it was only 5% in the other participants. Performance of prediction by receiver operating curve analyses showed area under the curve of >0.89 for both individual and combined CGM metric models.

Conclusions: TA140 >10% is associated with a high risk of progression to clinical diabetes within the next year in autoantibody positive children. CGM should be included in the ongoing monitoring of high-risk children and could be used as potential entry criteria for prevention trials.