Table 2.
Insulin Secretion, Insulin Sensitivity, and Disposition Index
Pre | Post | Δ | |
---|---|---|---|
Serum insulin | |||
Fasting, pM | 121 ± 8 | 90 ± 5b | −31 ± 7 |
2-h OGTT, pM | 754 ± 76 | 576 ± 91a | −180 ± 61 |
ΔI 0–30 min, pM | 449 ± 48 | 345 ± 31a | −107 ± 33 |
iAUC I 0–30 min, pM·min | 9872 ± 773 | 7391 ± 475b | −2480 ± 553 |
iAUC I 30–120 min, pM·min | 71 554 ± 6537 | 52 368 ± 5660b | −19 670 ± 5021 |
ΔI/G 0–30 min | 175 ± 22 | 124 ± 14a | −52 ± 17 |
iAUC I/G 0–30 min | 42.5 ± 3.5 | 33.5 ± 2.3b | −9.0 ± 2.2 |
iAUC I/G 30–120 min | 188 ± 21 | 142 ± 19a | −48 ± 14 |
Serum C-peptide | |||
Fasting, pM | 959 ± 54 | 841 ± 46a | −118 ± 38 |
2-h OGTT, pM | 3454 ± 187 | 3247 ± 195 | −207 ± 134 |
ΔC 0–30 min, pM | 946 ± 95 | 931 ± 94 | −15 ± 63 |
iAUC C 0–30 min, pM·min | 45 702 ± 2372 | 41 256 ± 2001 | −4446 ± 1553 |
iAUC C 30–120 min, pM·min | 239 064 ± 15 131 | 244 987 ± 16 234 | 5923 ± 10592 |
ΔC/G 0–30 min | 418 ± 60 | 359 ± 44 | −59 ± 53 |
iAUC C/G 0–30 min | 187 ± 11 | 181 ± 11 | −6.6 ± 6.7 |
iAUC C/G 30–120 min | 548 ± 51 | 578 ± 68 | 30 ± 52 |
Rate sensitivity, pM/mM | 284 ± 171 | 207 ± 81 | −27 ± 205 |
Clamp GDR, μmol/kg/min | 12.7 ± 0.7 | 18.7 ± 1.0b | 6.0 ± 0.7 |
Clamp insulin, pM | 480 ± 27 | 460 ± 25 | −20.9 ± 16.4 |
Insulin sensitivity, μmol/kg/min/pM | 0.0194 ± 0.0013 | 0.0309 ± 0.0022b | 0.012 ± 0.001 |
First-phase DI, a.u. | 707 ± 64 | 1054 ± 113b | 351 ± 89 |
Second-phase DI, a.u. | 3561 ± 317 | 6491 ± 672b | 2946 ± 489 |
Abbreviations: C, C-peptide; F, female; G, glucose; GDR, glucose disposal rate; I, insulin; M, male; Rate sensitivity, rate of change of serum C-peptide relative to the rate of change of plasma glucose; Δ0–30 min, increment between 0 and 30 min of OGTT. Δ values represent the exercise responsiveness of each variable.
Subjects (n = 105) with impaired glucose tolerance and recently diagnosed type 2 diabetes underwent 12- to 6 weeks of moderate-intensity aerobic exercise training, 5 days per week, 60 minutes per day. Body composition, aerobic fitness (VO2max), glucose tolerance (OGTT), insulin sensitivity (glucose clamp), and oral glucose-stimulated insulin secretion were measured.
Data indicate mean ± SEM. Paired t tests were used to compare pre- vs postexercise means. Statistical significance is represented by a P < .01 and b P < .001.