Abstract
Anemia in chronic hemodialysis patients is mainly caused by a deficiency of endogenous erythropoietin. There may also be other causes, such as iron deficiency, underdialysis and deficient protein intake. A correlation exists between iron metabolism and protein intake. In this study, we investigated the relationship between iron metabolism markers, and Kt/V and protein catabolic rate (PCR) based on urea kinetics in 121 chronic hemodialysis patients. The patients were divided into three groups: group 1 (n=52), no iron deficiency (Frt≥50ng/ml and %Tf≥30%); group 2 (n=37), absolute iron deficiency (Frt<50ng/ml); and group 3 (n=32), functional iron deficiency (%Tf<30% and Frt≥50ng/ml). The mean hematocrit (Ht) was 24.4±4.0% in group 1, 27.7±5.0% in group 2 and 23.8±4.3% in group 3 (group 2 vs group 1, 3; p<0.001).
Average Kt/V and PCR, on the other hand, were 1.17±0.15 and 1.08±0.27g/kg/day, respectively. There were no significant differences in Kt/V or PCR among the three groups, however, a significant negative correlation between %Tf and PCR was found between the patients as a whole and the patients in group 1 (p<0.05). It is generally recognized that %Tf is inversely proportional to Tf and directly proportional to serum Fe. Hypoproteinemia lowers Tf, however, %Tf rises when Tf levels are low. In conclusion, hypoproteinemia may activate hematopoiesis by %Tf elevation.
