Effects of IGF-1/IGFBP-3 treatment on total IGF-I (164 ±17 vs. 594 ± 61 ng/ml) (A), free IGF-I (0.67 ± 0.17 vs. 4.35 ± 0.46 ng/ml) (B), IGFBP-3 (3865 ± 336 vs. 4082 ± 341 ng/ml) (C), and insulin-mediated glucose uptake (3.60 ± 0.46 vs. 5.86 ± 0.86 mg/kg · min · μIU/ml) (D). Individual results and group mean ± sem are shown. *, P < 0.001; **, P < 0.05. ○, 0.5 mg/kg · d dose; •, 1.0 mg/kg · d dose.