Erythropoietin deficiency in hyporeninemia.
The association of anemia and hyporeninemic hypoaldosteronism (HRHA) in type 1 diabetes has been described, and erythropoietin deficiency has been proposed as the cause. Subjects with type 1 diabetes with (n = 8) and without HRHA (n = 11) were studied, as were subjects taking angiotensin-converting enzyme inhibitors (ACEIs; n = 10). Renal function and sodium excretion were estimated with a 24-hour urine collection. Values for hemoglobin, hematocrit, serum erythropoietin, and red blood cell volume were determined. HRHA subjects were anemic (hemoglobin, 99 +/- 8 g/L ), and ACEI subjects had lower hemoglobin concentrations (120 +/- 4 g/L) compared with controls (134 +/- 3 g/L; P < 0.001 and P = 0.01, respectively). Also, the red cell mass in patients with HRHA was significantly less than that in controls (14.8 +/- 1.4 v 20.8 +/- 1.1 mL/kg; P = 0.004), indicating that the lower hemoglobin level in HRHA is not attributable to an expansion of extracellular volume. Erythropoietin levels in the HRHA (27% +/- 11% of predicted) and ACEI groups (43% +/- 9% of predicted) were low compared with controls (94% +/- 13% of predicted; P = 0.001 and P = 0.005, respectively). Renal function was greater than the levels at which anemia becomes a clinical feature in all groups, but creatinine clearance was less in the HRHA (63 +/- 12 mL/min/1.73 m2) and ACEI groups (76 +/- 11 mL/min/1.73 m2) compared with controls (123 +/- 9 mL/min/1.73 m2; P < 0.001 and P = 0.004, respectively). The fractional sodium reabsorption was decreased in HRHA (98.7% +/- 0.3%) and ACEI groups (98.7% +/- 0.3%) versus controls (99.4% +/- 0.1%; P = 0.007 and P = 0.01, respectively). Subjects with type 1 diabetes with HRHA had low hemoglobin concentrations that were caused, at least in part, by inappropriately low serum erythropoietin levels.
Donnelly
S
S
Department of Medicine, Mount Sinai Hospital, Toronto, Canada. sandra.donnelly@utoronto.ca
Shah
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BR
D000328:Adult; D000740:Anemia / Q000209:etiology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications*; D004911:Erythrocyte Volume; D004921:Erythropoietin / Q000172:deficiency*; D005260:Female; D006400:Hematocrit; D006801:Humans; D006994:Hypoaldosteronism / Q000097:blood / Q000150:complications*; D008297:Male; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System
D000806:Angiotensin-Converting Enzyme Inhibitors; D004921:Erythropoietin; D012083:Renin