1343-P: A Comparison of C-Peptide and Glucose Responses between Children and Adolescents Who Progress to Type 1 Diabetes (T1D)

Abstract

Type 1 diabetes is a heterogeneous disease with differences in β-cell dysfunction and rates of progression. We thus assessed whether there are differences in C-peptide and glucose responses during 2-hour oral (OGTTs) and intravenous (IVGTTs) glucose tolerance tests between children and adolescents at high risk for T1D. Data from the Diabetes Prevention Trial-type 1 (DPT-1) study participants who progressed to T1D was used for the analysis. We compared C-peptide and glucose responses between children (<10.0 years old; 7.1±1.9 years; n=125) and adolescents (10.0 years to <18.0 years old; 12.8±2.2 years; n=94). The risks for T1D were similar between the children and adolescents (mean 3-year T1D estimates from DPT-1 Risk Score: 63% and 56% respectively), as was the time to diagnosis (2.4±2.1 years vs. 2.5±2.2 years, respectively). Adolescents had higher OGTT derived AUC C-peptide levels (3.8±1.5 ng/ml vs. 1.9±1.4 ng/ml; p<0.001 with BMIZ adjustment), whereas their AUC glucose levels were similar to children (138.6±25.1 mg/dl vs. 139.6±22.8 mg/dl). The 0 to 30 minute C-peptide response from baseline OGTTs was significantly higher among adolescents compared to children (2.6±1.6 vs. 2.1±1.2, p=0.004 with BMIZ adjustment). However, C-peptide and glucose changes for each subsequent 30-minute OGTT interval were nearly identical between the children and adolescents. Similar to the 0 to 30 minute C-peptide response, the first-phase insulin response from baseline IVGTTs was higher in adolescents (114.1±74.0 µU/ml vs. 88.6±59.9 µU/ml; p<0.001 with BMIZ adjustment). In conclusion, the findings showed that despite a lower early insulin response in children, OGTT glucose levels were not higher. This suggests increased insulin sensitivity. The findings also showed that despite the lower early insulin response, the time to diagnosis did not differ. Other aspects of insulin responsiveness, and perhaps sensitivity, appear to also determine the progression rate to T1D. Disclosure H.M. Ismail: None. B.M. Nathan: None. J.P. Palmer: None. L. DiMeglio: Research Support; Self; Amgen Inc., Caladrius Biosciences, Inc., Janssen Research & Development, Medtronic, Sanofi. Other Relationship; Self; Dexcom, Inc. J.M. Sosenko: None. Funding National Institutes of Health