Nathan, Brandon M.Boulware, DavidGeyer, SusanAtkinson, Mark A.Colman, PeterGoland, RobinRussell, WilliamWentworth, John M.Wilson, Darrell M.Evans-Molina, CarmellaWherrett, DianeSkyler, Jay S.Moran, AntoinetteSosenko, Jay M.Type 1 Diabetes TrialNet and Diabetes Prevention Trial–Type 1 Study Groups2019-06-282019-06-282017-11Nathan, B. M., Boulware, D., Geyer, S., Atkinson, M. A., Colman, P., Goland, R., … Type 1 Diabetes TrialNet and Diabetes Prevention Trial–Type 1 Study Groups (2017). Dysglycemia and Index60 as Prediagnostic End Points for Type 1 Diabetes Prevention Trials. Diabetes care, 40(11), 1494–1499. doi:10.2337/dc17-0916https://hdl.handle.net/1805/19744OBJECTIVE: We assessed dysglycemia and a T1D Diagnostic Index60 (Index60) ≥1.00 (on the basis of fasting C-peptide, 60-min glucose, and 60-min C-peptide levels) as prediagnostic end points for type 1 diabetes among Type 1 Diabetes TrialNet Pathway to Prevention Study participants. RESEARCH DESIGN AND METHODS: Two cohorts were analyzed: 1) baseline normoglycemic oral glucose tolerance tests (OGTTs) with an incident dysglycemic OGTT and 2) baseline Index60 <1.00 OGTTs with an incident Index60 ≥1.00 OGTT. Incident dysglycemic OGTTs were divided into those with (DYS/IND+) and without (DYS/IND-) concomitant Index60 ≥1.00. Incident Index60 ≥1.00 OGTTs were divided into those with (IND/DYS+) and without (IND/DYS-) concomitant dysglycemia. RESULTS: The cumulative incidence for type 1 diabetes was greater after IND/DYS- than after DYS/IND- (P < 0.01). Within the normoglycemic cohort, the cumulative incidence of type 1 diabetes was higher after DYS/IND+ than after DYS/IND- (P < 0.001), whereas within the Index60 <1.00 cohort, the cumulative incidence after IND/DYS+ and after IND/DYS- did not differ significantly. Among nonprogressors, type 1 diabetes risk at the last OGTT was greater for IND/DYS- than for DYS/IND- (P < 0.001). Hazard ratios (HRs) of DYS/IND- with age and 30- to 0-min C-peptide were positive (P < 0.001 for both), whereas HRs of type 1 diabetes with these variables were inverse (P < 0.001 for both). In contrast, HRs of IND/DYS- and type 1 diabetes with age and 30- to 0-min C-peptide were consistent (all inverse [P < 0.01 for all]). CONCLUSIONS: The findings suggest that incident dysglycemia without Index60 ≥1.00 is a suboptimal prediagnostic end point for type 1 diabetes. Measures that include both glucose and C-peptide levels, such as Index60 ≥1.00, appear better suited as prediagnostic end points.en-USPublisher PolicyBlood GlucoseC-PeptideChild, PreschoolCohort StudiesDiabetes Mellitus, Type 1Endpoint DeterminationFollow-Up StudiesGlucose Tolerance TestArticle