TABLE 5.
Indexes reflecting the metabolic response after a 13C-enriched oral-glucose-tolerance test in 45 overweight men and women after a 6-wk HDD or LDD in a crossover design1
| Fasting values | Peak values | Time to peak (min) | iAUC (0–2 h) | iAUC (0–4 h) | iAUC (0–8 h) | |
|---|---|---|---|---|---|---|
| Glucose, mmol/L | ||||||
| LDD | 5.5 ± 0.3 | 10.6 ± 1.6 | 61.0 ± 20.8 | 397.8 ± 132.7 | 490.2 ± 176.9 | 496.3 ± 177.4 |
| HDD | 5.5 ± 0.3 | 10.9 ± 1.7 | 58.0 ± 21.1 | 393.6 ± 132.9 | 484.9 ± 179.3 | 502.7 ± 184.8 |
| Insulin, µU/mL | ||||||
| LDD | 8.1 ± 2.8 | 115.9 ± 55.9 | 69.4 ± 29.5 | 7621 ± 3700 | 10,495 ± 5764 | 10,653 ± 5797 |
| HDD | 8.9 ± 3.3* | 119.2 ± 59.1 | 72.2 ± 28.2 | 7927 ± 4228 | 11,030 ± 6255 | 11,135 ± 6304 |
| RQ | ||||||
| LDD | 0.74 ± 0.04 | 0.87 ± 0.04 | 147.3 ± 46.5 | 4.77 ± 3.11 | 16.96 ± 9.32 | 21.73 ± 14.75 |
| HDD | 0.75 ± 0.04 | 0.87 ± 0.04 | 146.4 ± 55.1 | 4.69 ± 3.11 | 16.16 ± 6.92 | 20.56 ± 9.97 |
| RaT, mg · kg−1 · min−1 | ||||||
| LDD | 2.4 ± 0.4 | 7.5 ± 1.4 | 43.6 ± 18.2 | 381.0 ± 94.1 | 522.1 ± 115.8 | 523.6 ± 114.3 |
| HDD | 2.5 ± 0.3 | 7.2 ± 1.2 | 48.8 ± 22.2 | 366.0 ± 97.1 | 503.3 ± 113.3 | 504.2 ± 114.0 |
| RaE, mg · kg−1 · min−1 | ||||||
| LDD | 0.0 ± 0.0 | 6.5 ± 1.3 | 49.9 ± 20.4 | 535.8 ± 99.4 | 854.8 ± 115.4 | 971.7 ± 119.9 |
| HDD | 0.0 ± 0.0 | 6.4 ± 1.2 | 55.5 ± 29.9 | 534.5 ± 103.0 | 862.4 ± 116.3 | 976.0 ± 116.8 |
| EGP, mg · kg−1 · min−1 | ||||||
| LDD | 2.4 ± 0.4 | 0.32 ± 0.3 | 119.3 ± 60.9 | 155.2 ± 35.4 | 353.1 ± 68.9 | 618.8 ± 127.6 |
| HDD | 2.5 ± 0.3 | 0.37 ± 0.3 | 126.6 ± 74.1 | 169.5 ± 31.6** | 377.2 ± 58.2** | 671.5 ± 123.7* |
| GCR, mL · kg−1 · min−1 | ||||||
| LDD | 2.4 ± 0.4 | 5.1 ± 1.2 | 120.4 ± 47.0 | 109.0 ± 81.8 | 271.4 ± 132.1 | 284.9 ± 134.5 |
| HDD | 2.6 ± 0.4 | 5.1 ± 1.2 | 136.1 ± 36.7* | 100.0 ± 79.3 | 261.1 ± 133.1 | 273.2 ± 134.3 |
| 13CO2 (% dose/h) | ||||||
| LDD | 0.0 ± 0.0 | 6.8 ± 0.8 | 233.3 ± 34.4 | 3.46 ± 0.73 | 15.01 ± 2.14 | 34.76 ± 4.38 |
| HDD | 0.0 ± 0.0 | 6.9 ± 0.8 | 228.0 ± 30.3 | 3.52 ± 0.73 | 15.32 ± 1.92 | 35.44 ± 4.08* |
1Values are mean ± SD, n = 45 (n = 43 for glucose kinetics). Differences were assessed using linear mixed models. RQ iAUC is based on deviating time frames (t = 0–95, 0–230, and 0–455 min). Because EGP was suppressed after the test meals, the nadir values and time to nadir are presented. Also, the area beneath baseline (decremental AUC) was calculated using mirrored data. For 13CO2, the cumulative values (% dose) are presented under iAUC. *,**Significantly different from LDD: *P < 0.05, **P < 0.01. EGP, endogenous glucose production; GCR, glucose clearance rate; HDD, high-dairy diet; iAUC, incremental AUC; LDD, low-dairy diet; RaE, rate of appearance of exogenous glucose; RaT, rate of appearance of total glucose; RQ, respiratory quotient.