Growth hormone and cortisol secretion before and after erythropoietin therapy in CAPD patients

Correction of anemia with recombinant human erythropoietin (rHuEPO) in patients with end-stage renal disease (ESRD) has been associated with improvement of several endocrine abnormalities. However, long-term effects of this therapy on pituitary secretion in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) is not known. The aim of the present work was to assess the growth hormone (GH) and cortisol responses to insulin-induced hypoglycemia before and after the correction of anemia with rHuEPO therapy in CAPD patients. Five well-nourished and clinically stable patients were studied before and after 12-24 weeks of rHuEPO treatment. Seven normal volunteers were studied as controls. Insulin-induced hypoglycemia tests were performed prior to starting rHuEPO therapy and again after partial correction of anemia. Blood samples for GH, cortisol, and glucose were collected between -30 and 120 min after insulin (0.1 U/kg bw) administration. GH responses to hypoglycemic stress were characterized by marked differences in single patients when compared with the control group. However, the GH peak and the area under the secretory curves (AUC) of GH responses in CAPD patients (10.6 +/- 4.8 micrograms/L and 15.4 +/- 6.1 micrograms h/L, respectively) did not differ from those obtained in control subjects (14.3 +/- 4.1 micrograms/L and 19.4 +/- 3.5 micrograms h/L, respectively). The study, after correction of anemia, showed an evident decrease of GH values at each time point on the response curve in 4 patients, and no modification in 1 patient. Mean values of GH peak and AUC were 8.8 +/- 2.8 micrograms/L and 9.6 +/- 2.3 micrograms h/L.(ABSTRACT TRUNCATED AT 250 WORDS)