FUNCTION OF ENDOCRINE ORGANS IN HEMODIALYZED PATIENTS OF LONG-TERM ERYTHROPOIETIN THERAPY

Endocrine abnormalities in patients with chronic renal failure are wel l documented. The present study aimed to assess the influence of long- term erythropoietin (EPO) therapy on endocrine abnormalities in hemodi alyzed patients. Two groups of hemodialyzed patients, each of which co mprised 17 subjects, were examined. The first group was treated by EPO (EPO group) while the second one did not receive this hormone (No-EPO group). A complete biochemical and hormonal check-up was performed be fore and at the 3, 6, 9, and 12 month points of the study period. Norm al values for the estimated parameters were obtained in appropriately selected sex- and age-matched healthy subjects. After EPO therapy, an increase of the hematocrit value from 21.8 +/- 0.9 to 32.6 +/- 0.9% wa s observed, which was accompanied by a significant decline of plasma f erritin and saturation of transferrin. In patients of the No-EPO group , a significant although less marked rise of the hematocrit value (21. 4 +/- 0.4 to 24.2 +/- 0.6%) was also noticed, EPO therapy did not chan ge plasma levels of electrolytes (Na, K, Ca, inorganic phosphate), ost eocalcin, creatinine, glucose, and alkaline phosphatase as well as pla sma concentrations of calcium-related hormones (PTH, calcitonin, 1,25[ OH]D-2(3)), vasopressin, and triiodothyronine. EPO treatment induced a significant decrease in somatotropin, prolactin, follitropin, lutropi n, ACTH, cortisol, plasma renin activity, aldosterone, noradrenaline, adrenaline, dopamine, glucagon, pancreatic polypeptide, and gastrin pl asma levels and an increase in plasma insulin, estradiol, testosterone , atrial natriuretic peptide, thyrotropin, and thyroxine. These EPO-in duced endocrine alterations were restricted mostly to the first 6 mont hs of EPO administration. In patients of the No-EPO group, a significa nt decrease in the plasma levels of prolactin, noradrenaline, and dopa mine and an increase of estradiol plasma levels were also noticed duri ng the 1-year study period. Therefore, long-term treatment by EPO show s profound effects on the function of several endocrine organs. These effects are transitory and predominantly restricted to the first 6 mon ths of EPO therapy. Not all endocrine alterations observed in EPO-trea ted patients seem to be due to the administration of this hormone.