Continuous Glucose Monitoring Predicts Progression to Diabetes in Autoantibody Positive Children

J Clin Endocrinol Metab. 2019 Aug 1;104(8):3337-3344. doi: 10.1210/jc.2018-02196.


Context: Accurate measures are needed for the prediction and diagnosis of type 1 diabetes (T1D) in at-risk persons.

Objective: The purpose of this study was to explore the value of continuous glucose monitoring (CGM) in predicting T1D onset.

Design and setting: The Diabetes Autoimmunity Study in the Young (DAISY) prospectively follows children at increased risk for development of islet autoantibodies (islet autoantibody positive; Ab+) and T1D.

Participants: We analyzed 23 Ab+ participants with available longitudinal CGM data.

Main outcome measure: CGM metrics as glycemic predictors of progression to T1D.

Results: Of 23 Ab+ participants with a baseline CGM, 8 progressed to diabetes at a median age of 13.8 years during a median follow-up of 17.7 years (interquartile range, 14.6 to 22.0 years). Compared with nonprogressors, participants who progressed to diabetes had significantly increased baseline glycemic variability (SD, 29 vs 21 mg/dL; P = 0.047), daytime sensor average (122 vs 106 mg/dL; P = 0.02), and daytime sensor area under the curve (AUC, 470,370 vs 415,465; P = 0.047). They spent 24% of time at >140 mg/dL and 12% at >160 mg/dL compared with, respectively, 8% and 3% for nonprogressors (both P = 0.005). A receiver-operating characteristic curve analysis showed an AUC of 0.85 for percentage of time spent at >140 or 160 mg/dL. The cutoff of 18% time spent at >140 mg/dL had 75% sensitivity, 100% specificity, and a 100% positive predictive value for diabetes prediction, although these values could change because some nonprogressors may develop diabetes with longer follow-up.

Conclusions: Eighteen percent or greater CGM time spent at >140 mg/dL predicts progression to diabetes in Ab+ children.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Autoantibodies / blood*
  • Blood Glucose Self-Monitoring / statistics & numerical data*
  • Diabetes Mellitus, Type 1 / diagnosis*
  • Disease Progression
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Predictive Value of Tests
  • Prospective Studies
  • ROC Curve
  • Sensitivity and Specificity
  • Young Adult


  • Autoantibodies