Table 2—

Fasting and stimulated C-peptide concentrations

TrialNet
ECPT
MMTTGSTMMTTGST
n143135116117
Tests278271174174
Fasting (pmol/ml)0.17 (0.14–0.19)0.17 (0.15–0.20)0.07 (0.05–0.08)0.07 (0.05–0.08)
Peak stimulated (pmol/ml)0.40 (0.38–0.42)0.30 (0.28–0.32)*0.13 (0.12–0.15)N/A
90-min MMTT/6-min GST (pmol/ml)0.36 (0.34–0.38)0.27 (0.25–0.28)*0.12 (0.11–0.13)0.10 (0.09–0.10)*
AUC mean (pmol/ml)0.31 (0.29–0.33)0.25 (0.24–0.26)*0.11 (0.10–0.11)N/A
  • Data are geometric means (95% CI). Geometric means, calculated as exp[mean log(x)], are from a mixed-model analysis of the log(C-peptide) adjusted for fasting glucose concentration, age, sex, continuous diabetes duration, test order, and sequence group. Analyses of stimulated values were also adjusted for basal log(C-peptide). Analyses were conducted separately for TrialNet and EPCT.

  • * P < 0.0001 for the comparison between the TrialNet GST and MMTT. N/A, not applicable.