Visual Abstract

Background: Clinical onset of type 1 diabetes (Stage 3 T1D) is preceded by a pre-symptomatic phase characterized by multiple islet autoimmunity with normal glucose tolerance (Stage 1 T1D), followed by dysglycemia (Stage 2). The metabolic phenotypes of beta-cell function and insulin sensitivity were explored in normoglycemic youth with stage 1 T1D and compared to healthy non-related peers during a 3-h oral glucose tolerance test (OGTT).

Methods: Participants were recruited from TrialNet (cases) and Yale University (controls). Twenty-eight lean youth with at least two islet autoantibody (cases) and 32 healthy controls underwent a 3-hour 9-point OGTT with measurement of glucose, C-peptide and insulin. The oral minimal model was used to quantitate beta-cell responsivity (Phitotal) and insulin sensitivity (SI), allowing assessment of beta-cell function by the disposition index, DI=Phitotal x SI. Subjects with impaired fasting glucose, impaired glucose tolerance or any OGTT glucose concentration >200mg/dL were excluded.

Results: Cases (10.5y[8, 15]) exhibited reduced DI (p<0.001) due to a simultaneous reduction in both Phitotal (p<0.001) and SI (p=0.008) as compared to controls (11.5y[10.4, 14.9]).

Conclusion: Pre-symptomatic stage 1 T1D is associated with both reduced insulin sensitivity and lower beta cell responsiveness in youth.


A. Galderisi: None. A. Moran: Advisory Panel; Self; Dompe, Novo Nordisk, Research Support; Self; Abbott Diabetes, Intrexon, Provention Bio, Inc. C. Evans-molina: Advisory Panel; Self; Provention Bio, Inc., Consultant; Self; Dompe, Other Relationship; Self; Bristol-Myers Squibb Company, Nimbus Pharmaceuticals, Pfizer Inc. M. Martino: None. N. Santoro: None. S. Caprio: None. C. Cobelli: None.


Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD40787, R01DK111038, R01HD28016, R01DK114504); National Center for Research Resources (UL1RR0249139); National Institute of Diabetes and Digestive and Kidney Diseases (R01DK111038); Diabetes Research Center (P30DK045735, R01DK114504-01A, K12AWDA10768, GR103182); National Institutes of Health (U01DK085476, UL1TR002494, U01DK085505); Fondazione Cassa di Risparmio di Padova e Rovigo (2018); European Commission (EU951933)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at