Table 3.

Measurements of plasma leucine concentration, MCR, and metabolism

Placebo GH
0 mo 2 mo 0 mo 2 mo
Plasma leucine conc
 Basal130 ± 8 133 ± 6 138 ± 10135 ± 11
 Peak 201 ± 113-152 192 ± 93-152 203 ± 193-152 180 ± 113-152
Plasma leucine AUC 43.6 ± 2.2 42.2 ± 2.244.2 ± 3.4 39.0 ± 1.9
Leucine MCR
 Basal 34.65 ± 2.61 33.00 ± 1.9930.86 ± 2.91 36.76 ± 3.313-150
 Peak39.60 ± 3.44 39.25 ± 3.6235.48 ± 5.27 45.08 ± 5.683-151
Leucine MCR AUC7,510 ± 512 7,032 ± 496 6,577 ± 9368,631 ± 9013-151
Leucine Ra
 Basal4.15 ± 0.23 4.1 ± 0.28 3.95 ± 0.374.74 ± 0.62
 Peak 6.08 ± 0.403-152 5.37 ± 0.203-152 5.57 ± 0.853-152 6.60 ± 1.053-152
Leucine Ra AUC1,233 ± 47 1,103 ± 37 1,082 ± 1301,300 ± 1753-150
NOLD
 Basal 3.60 ± 0.183.48 ± 0.20 3.16 ± 0.314.10 ± 0.533-151
 Peak 4.42 ± 0.233-152 4.16 ± 0.223-152 4.14 ± 0.463-152 5.22 ± 0.733-152
NOLD AUC 1,011 ± 339920 ± 32 847 ± 62 1,091 ± 1323-150
Leucine oxidation
 Basal 0.55 ± 0.070.63 ± 0.10 0.79 ± 0.120.64 ± 0.103-150
 Peak 1.87 ± 0.163-152 1.42 ± 0.063-152 1.68 ± 0.493-152 1.67 ± 0.333-152
Leucine oxidation AUC275 ± 20 235 ± 13 278 ± 78265 ± 51
  • Measurements of plasma leucine concentration (μmol/l), metabolic clearance rate (MCR, ml ⋅ kg LBM−1 ⋅ min−1), and metabolism [production rate (Ra), nonoxidative leucine disappearance (NOLD), and oxidation; μmol ⋅ kg LBM−1 ⋅ min−1] before (basal) and after a standard meal [peak values and AUCs for 240 min (μmol ⋅ l−1 ⋅ min, ml/kg LBM, and μmol/kg LBM, respectively)]. Peak values were not at same time in each subject.

  • F3-150 Significantly different from 0 mo (P < 0.05).

  • F3-151 Significantly different from 0 mo (P < 0.03).

  • F3-152 Significantly different from basal (P < 0.05).