EFFECTS OF RECOMBINANT GROWTH-FACTORS ON ENERGY-EXPENDITURE IN MAINTENANCE HEMODIALYSIS-PATIENTS

We compared the metabolic effects of recombinant human (rh) insulin-li ke growth factor (IGF)-1 or a combination of rhIGF-1 + rh growth hormo ne (GH) on resting energy expenditure (REE) in 8 maintenance hemodialy sis (MI-ID) patients. Seven males and 1 female (aged 41.6 +/- (SD) 12. 4) with no evidence of malnutrition (BMI 21.6 +/- 2.2 kg/m(2), serum a lbumin 45 +/- 2 g/l, serum IGF-1 359 +/- 165 mu g/l) received either r hIGF-1 (80 mu g/kg/day) or rhIGF-1 (80 mu g/kg/day)+ rhGH (50 mu g/kg/ day) for 3 days in a random crossover design. REE and the respiratory quotient (RQ) were measured at rest before and after the 3-day treatme nt. The results confirmed that MI-ID patients have a REE not different from normal individuals. REE was strongly correlated with lean body m ass but not with fat mass. rhIGF-1 treatment did not modify REE despit e doubling serum IGF-1 values, whereas a combined rhIGF1 + rhGH treatm ent significantly increased REE by 11% (p < 0.001). There was no chang e in RQ under both treatments, in response to a proportionate increase in V-Co2 and V-o2. These results show that energy expenditure is main ly dependent upon lean body mass in well-nourished MI-ID patients. The metabolic effects of rhIGF-1 and rhGH on energy expenditure may diffe r in response to their opposite effects on lipid oxidation and insulin regulation.