Table 2

OGTT-based measures in drug-naïve youth and adults subdivided based on glucose tolerance category (IGT vs. type 2 diabetes)

Youth (n = 66)Adults (n = 355)Youth IGT vs. adults IGT, P value (1 vs. 3)Youth with type 2 diabetes vs. adults with type 2 diabetes, P value (2 vs. 4)
IGT (n = 53) (1)Type 2 diabetes (n = 13) (2)P value (1 vs. 2)IGT (n = 251) (3)Type 2 diabetes (n = 104) (4)P value (3 vs. 4)
Glycemic characteristic
 HbA1c (mmol/mol)36.78 ± 4.5745.70 ± 6.52<0.00138.77 ± 3.9341.73 ± 4.62<0.0010.0010.006
OGTT parameters
 Fasting glucose (mmol/L)5.64 ± 0.537.10 ± 1.29<0.0016.01 ± 0.556.5 ± 0.75<0.001<0.0010.014
 Fasting C-peptide (nmol/L)1.601 ± 0.6081.791 ± 0.4830.2991.223 ± 0.4201.281 ± 0.5980.303<0.0010.004
 Fasting insulin (pmol/L)215.9 (63.9, 729.4)227.7 (111.9, 463.4)0.768106.8 (37.9, 300.6)105.6 (30.7, 363)0.870<0.0010.002
 Two-hour glucose (mmol/L)9.13 ± 1.3412.97 ± 3.51<0.0019.39 ± 1.8611.99 ± 2.45<0.0010.3380.202
 Two-hour C-peptide (nmol/L)6.01 ± 2.485.11 ± 1.50.2164.81 ± 1.54.51 ± 1.650.089<0.0010.214
 Two-hour insulin (pmol/L)1,527.5 (362.1, 6,444.3)1,049.8 (432.9, 2,545.8)0.084812.2 (240.5, 2,742.6)735.2 (212.8, 2,540)0.173<0.0010.248
Incremental OGTT AUC (0–180 min)
 G-iAUC (mmol/L · min)528.9 ± 164.4858.8 ± 288.2<0.001540.7 ± 197.9786 ± 277.8<0.0010.6900.377
 CP-iAUC (nmol/L · min)555 (258.4, 1,192.1)429.8 (248.7, 742.9)0.036442.9 (239.0, 820.7)383.2 (174.0, 843.8)<0.001<0.0010.339
 I-iAUC (pmol/L · min)185,932 (51,812, 667,233)124,745 (50,683, 307,030)0.04297,185 (32,857, 287,458)78,599 (21,703, 284,646)0.002<0.0010.016
Estimates of insulin sensitivity, insulin clearance, and β-cell function
 1/FI × [10−3 1/(pmol/L)]5.65 ± 4.254.65 ± 1.560.40810.74 ± 5.8911.43 ± 7.520.359<0.0010.002
 Fasting C-peptide/insulin (× 10−2 nmol/pmol)0.69 (0.34, 1.42)0.76 (0.53, 1.09)0.3731.08 (0.60, 1.95)1.12 (0.57, 2.22)0.356<0.001<0.001
 CPI (nmol/mmol)0.815 (0.293, 2.263)0.385 (0.183, 0.81)<0.0010.46 (0.169, 1.248)0.287 (0.106, 0.779)<0.001<0.0010.048
 IGI (pmol/mmol)301.8 (66.8, 1,363.4)134.4 (49.0, 368.8)<0.001133.4 (34.4, 516.4)79.8 (21.9, 291.7)<0.001<0.0010.007
 CP-iAUC/G-iAUC (nmol/mmol)1.119 (0.447, 2.798)0.536 (0.214, 1.343)<0.0010.891 (0.359, 2.211)0.525 (0.18, 1.529)<0.0010.0020.897
 I-iAUC/G-iAUC (pmol/mmol)374.7 (102.4, 1,370.4)153.5 (44.9, 525)<0.001195.6 (58.3, 656.3)108 (25.5, 456.8)<0.001<0.0010.102
  • Data are mean ± SD or geometric mean (95% CI). P values for nonnormally distributed data based on log-transformed values.