Several alterations of growth hormone (GH) secretion have been described in patients with chronic renal failure. The effect of chronic treatment with recombinant human erythropoietin (rHuEPO) on GH secretion in uremic patients undergoing continuous ambulatory peritoneal dialysis (CAPD) is not known. The purpose of this study was to assess the GH responses to both direct and hypothalamic stimuli in CAPD patients chronically treated with rHuEPO. Eight clinically stable and well-nourished patients (age 19-59 yr) treated with subcutaneous rHuEPO, 96.5 +/- 72.1 U/kg/week, during 6-25 months were tested with GH-releasing hormone (GHRH, 100 micrograms iv in bolus). Insulin-induced hypoglycemia (0.1 U/kg iv in bolus) and clonidine (0.15 mg/m2 po) were used as indirect stimuli for GH release. Baseline concentrations of insulin-like growth factor I (IGF I) concentration was also determined. Five CAPD patients matched for age and sex and not previously treated with EPO were studied as a control group. There was no statistically significant difference in baseline IGF I concentrations in EPO treated patients in comparison with control group (2.6 +/- 0.7 vs 0.9 +/- 0.3 U/ml). GHRH administration was followed by a GH release in the treated group that did not differ significantly from that obtained in controls (peak: 10.6 +/- 3.7 vs 15.2 +/- 7.8 micrograms l, area under the curve [AUC]: 16.3 +/- 5.6 vs 24.0 +/- 11.4 micrograms.h/l).(ABSTRACT TRUNCATED AT 250 WORDS)