One-Hour Oral Glucose Tolerance Tests (OGTTs) for the Prediction and Diagnostic Surveillance of Type 1 Diabetes (T1D)

Natural history studies and prevention trials for T1D use 2 hour OGTTs for two main goals: prediction and diagnostic surveillance. Although 2 hour OGTTs are reliable for these purposes, they impose time burdens and costs for research participants and staff. We thus examined whether 1 hour OGTTs are suitable for prediction and diagnostic surveillance. To assess their accuracy for prediction, we developed a 1 hour risk score similar to the Diabetes Prevention Trial-Type 1 Risk Score (DPTRS). The DPTRS utilizes log fasting C-peptide, sums of 30, 60, 90 and 120-min glucose and C-peptide, age, and log BMI. The components are the same for the 1 hour risk score (DPTRS60) and the DPTRS except that 1 hour glucose and C-peptide replace the glucose sum and C-peptide sum. Diabetes Prevention Trial-Type 1 participants were included in the analysis (n=670; age at baseline: 13.8±9.6 years; 56% male; 241 diagnosed with T1D). 1 hour glucose and C-peptide were highly predictive of T1D within the DPTRS60 model, as were log fasting C-peptide, age and log BMI (all p Disclosure K. Simmons: None. J. Sosenko: None. H.M. Ismail: None. H. Elding Larsson: None. A. Steck: None.