A COMPARISON OF THE EFFECTS OF IGF-I AND INSULIN ON GLUCOSE-METABOLISM, FAT-METABOLISM AND THE CARDIOVASCULAR-SYSTEM IN NORMAL HUMAN VOLUNTEERS

The metabolic and cardiovascular effects of recombinant human ICE-I we re compared to insulin in six normal subjects. Subjects were studied t wice and intravenously received an infusion of [6,6-H-2(2)]glucose (0- 480 min) and in random order either IGF-I 20 mu g kg(-1) h(-1) (43.7 p mol kg(-1) min(-1)) or insulin 0.5 mU kg(-1) min(-1) (3.4 pmol kg(-1) min(-1)) with an euglycaemic clamp. One subject was withdrawn followin g a serious adverse event. During the ICE-I infusion glucose appearanc e rate (Ra) decreased from 1.79 +/- 0.13 at baseline (150-180 min) to 0.35 +/- 0.26 mg kg(-1) min(-1) (P < 0.01) at 360 min, and glucose uti lization rate (Rd) increased from 1.79 +/- 0.28 to 4.17 +/- 0.84 mg kg (-1) min(-1) (P < 0.01). There was no change in free fatty acids (FFA) and an increase (percentage change from pre-infusion mean) in cardiac output + 37.3% +/- 9% (P < 0.01), heart rate + 13% +/- 2% (P < 0.01) and stroke volume + 21% +/- 7% (P < 0.05). During the insulin infusion glucose Ra decreased from 1.89 +/- 0.13 to 0.34 +/- 0.33 mg kg(-1) mi n(-1) (P < 0.01) and FFA from 0.546 mmol l(-1) to 0.198 mmol l(-1) (P < 0.01), glucose Rd increased from 1.89 +/- 0.18 to 5.41 +/- 1.47 mg k g(-1) min(-1) (P < 0.01) and there were no significant changes in the cardiovascular variables.