Table 5.
Coefficient of variation (%) for selected β-cell function measures obtained using oral and intravenous testing in humans
| NGT | IGT | Diabetes | Diabetes (no meds) | All | Reference | |
|---|---|---|---|---|---|---|
| Oral glucose tolerance test (OGTT) | ||||||
| Fasting glucose | 4.0 | 5.2 | 4.3 | 4.8 | 4.5 | (478) |
| 2-hour glucose | 24.9 | 11.0 | 8.0 | 5.9 | -- | (478) |
| Fasting insulin | 19.3 | 14.3 | 16.5 | 17.1 | 16.6 | (478) |
| Fasting C-peptide | 11.5 | 10.8 | 7.2 | 8.3 | 9.7 | (478) |
| HOMA-IR | 19.1 | 14.4 | 16.1 | 17.0 | 16.4 | (478) |
| ∆Insulin0-30/∆glucose0-30 | 41.1 | 62.9 | 69.1 | 79.7 | 57.1 | (478) |
| ∆C-peptide0-30/∆glucose0-30 | 42.3 | 37.4 | 27.3 | 32.3 | 34.7 | (478) |
| IncAUCinsulin/IncAUCglucose | 29.4 | 27.0 | 19.2 | 22.7 | 24.9 | (478) |
| IncAUCC-peptide/IncAUCglucose | 25.5 | 14.2 | 10.0 | 9.0 | 17.7 | (478) |
| Model-derived parameters from an oral glucose tolerance test (OGTT) | ||||||
| Glucose sensitivity a | 17.2 | 16.5 | 20.3 | 20.3 | 20.3 | (478) |
| Rate sensitivity a | 42.1 | 40.5 | 114.8 | 76.2 | 44.6 | (478) |
| Potentiation a | 43.6 | 26.7 | 26.9 | 26.1 | 33.0 | (478) |
| φ db | 31 | (493) | ||||
| φ sb | 18 | (493) | ||||
| Intravenous glucose tolerance test (IVGTT) | ||||||
| AIRglucose (first-phase insulin response) | 20.6 | -- | -- | -- | -- | (494) |
| 20.1 | -- | -- | -- | -- | (495) | |
| Kg (glucose disappearance constant) | 14.5 | -- | -- | -- | -- | (494) |
| 51.4 | -- | -- | -- | -- | (495) | |
| SI (insulin sensitivity index)c | 16.9 | -- | -- | -- | -- | (494) |
| 20.2 | -- | -- | -- | -- | (495) | |
| Hyperglycemic clamp | ||||||
| Fasting insulin | 13.2 | -- | -- | -- | -- | (496) |
| AIRglucose (first-phase insulin response) | 10.4 | -- | -- | -- | -- | (496) |
| Maximal insulin response to arginine | 16.3 | -- | -- | -- | -- | (496) |
Abbreviations: AIRglucose, acute insulin response to glucose; ∆C-peptide0-30/∆C-peptide0-30, C-peptide index; ∆Insulin0-30/∆glucose0-30, insulinogenic index; IncAUC, incremental area under the curve; Kg, glucose disappearance constant.
a calculated using a model developed by Mari and colleagues (486)
b calculated using a model developed by Cobelli and colleagues (487)
c calculated using the minimal model of glucose kinetics developed by Bergman and colleagues (108)