Table 1.

Overview of donor cohort characteristics

Donor Group	N	Age, yr	Disease Duration, yr	Sex (F/M)	BMI, kg/m²	HbA1c, %	C-Peptide, ng/mL
Non-diabetic	11	31 ± 15	N/A	3/11	30 ± 13	5.57 ± 0.30	13.18 ± 11.41
T1D Recent-onset (<10 yr)	15	25 ± 14	6 ± 2	5/15	24 ± 6	9.49 ± 0.168	0.11 ± 0.13* (vs. ND and T1D >10 yr)
T1D Longstanding (>10 yr)	12	45 ± 14	31 ± 11	3/12	27 ± 5	8.9 ± 1.45	< 0.02 or UD* (vs. ND and T1D <10 yr)

Averages are displayed as means ± SD (N = sample size) when applicable for non-diabetic (ND) and type 1 diabetes (T1D) donors. For statistical purposes, C-peptide values < 0.02 ng/mL (the lower limit of assay detection) and undetectable C-peptide levels were set to 0. For recent-onset T1D, 4 donors had C-peptide values < 0.02 ng/mL and 3 donors had undetectable values. For longstanding T1D, 7 donors had C-peptide levels < 0.02 ng/mL and 4 donors had undetectable values. The longstanding T1D donor with a C-peptide level of 1.78 was determined to be an outlier and excluded from analyses. BMI, body mass index; F, female; HbA1c, hemoglobin A1c; M, male; UD, undetectable. *Statistically significant, P value < 0.05 for comparisons between donor groups assessed by Mann–Whitney tests.