Iron and Zinc Status of Patients with Chronic Renal Failure Who Are Not on Dialysis

Objective: The purpose of this study was to assess the zinc and iron status in patients with chronic renal failure (CRF) who were not receiving dialysis.

Design: Cross-sectional study.

Setting: Outclinic patients of the Nephrology Division at Federal University of São Paulo.

Patients: This study was performed on 29 stable patients with CRF who were not receiving dialysis.

Main Outcome Measure: The parameters for determining iron and zinc status were transferrin saturation, zinc protoporphyrin, serum ferritin, hematocrit, serum iron, total iron binding capacity, erythrocyte, and plasma zinc levels (measured by atomic absorption spectrophotometry).

Results: The serum ferritin level was reduced to 85.5 +/- 67.1 ng/mL and the zinc protoporphyrin level was high (68 +/- 32.9 micromol/mol heme), serum transferrin saturation was 19.9% +/- 7.85%, mean serum iron level was 66.6 +/- 26.3 microg/dL, and mean total iron binding capacity was 336 +/- 45.7 microg/dL. Absolute iron deficiency was found in 34.5% of the patients. Zinc level in erythrocytes was high (50.0 +/- 7.2 microg/g hemoglobin), whereas plasma zinc was at a borderline level (74 +/- 17.7 microg/dL) when compared with normal values. There were significant correlations among plasma zinc and serum iron and transferrin saturation, zinc erythrocyte, and parameters of iron.

Conclusion: These results show that absolute iron deficiency can occur in patients who are not receiving dialysis and that there is an abnormal distribution of zinc levels in these patients. Moreover, a possible relationship between iron deficiency and zinc distribution was observed.