The Impact of Anemia in the Pathogenesis of Endocrine Abnormalities in Chronic Renal Failure

Abstract

Endocrine abnormalities are well characterized in uremic patients. On the other hand it is known that erythropoietin (EPO) treatment in patients with chronic uremia is accompanied by several beneficial, as well as by adverse effects, which suggest the participation of endocrine organs in the pathogenesis of this disease. In this paper we report the effects of three months EPO treatment on the function of several endocrine organs in hemodialyzed patients. Endocrine parameters were assessed before and after 3 months on EPO treatment, as well as 3 months after EPO administration was discontinued. Results obtained in these patients were compared with those established in appropriately selected healthy subjects, as well as with those found in hemodialyzed uremic patients (not receiving EPO) with a hematocrit value of the same magnitude as that determined in patients after EPO treatment. Treatment with EPO was followed by suppression of basal plasma levels of somatotropin, prolactin, follitropin, lutropin, adrenocorticotropic hormone (ACTH), cortisol, and aldosterone and by a moderate increase of plasma parathyroid hormone (PTH) and testosterone. Treatment with EPO did not significantly influence plasma calcitonin and 25-OH-D levels or the function of the pituitary-thyroid feedback. After 3 months of EPO treatment we found a suppression of plasma renin activity, but an increase of plasma atrial natriuretic peptide level. Treatment with EPO increased insulin, but suppressed plasma levels of glucagon, gastrin, and to a lesser degree, those of the pancreatic polypeptide. Some EPO-induced endocrine alterations were still present three months after the discontinuation of EPO therapy. From data presented in this study, it follows that EPO treatment is accompanied by profound endocrine alterations and that these alterations do not seem to be related only to the improvement of anemia.