High Normal Thyrotropin (TSH) is Associated with Higher Needed Dose of Erythropoietin in Hemodialysis Patients

Background: Recombinant human erythropoietin demonstrated an impressive ability to improve hematocrit, raising hematocrit of hemodialysis patients, eliminating the need for transfusions, and in patients with iron overload, decreased serum ferritin. Thyrotropin could affect hematopoiesis by binding to a functional thyrotropin receptor, which is found in both erythrocytes and some extrathyroidal tissues. The aim of this study was to evaluate the relationship of Thyrotropin level within normal reference range (in euthyroid state) on erythropoietin dose in end-stage renal disease patients on hemodialysis.

Methods: Prospective cross-sectional study was carried out at the hemodialysis units. It included 60 patients who had end-stage renal disease on hemodialysis. The selected patients were classified into 2 groups: Group A: included 30 end-stage renal disease patients on hemodialysis with Thyrotropin level (0.4-<2.5 miu/L) and Group B: included 30 end-stage renal disease patients on hemodialysis with Thyrotropin level (2.5-4.2 miu/L).

Results: the hemoglobin level and the hematocrit level showed a highly statistically significant difference between both groups. The needed Erythropiotin dosage was higher in group B than in group A with highly statistically significant difference. Weighted Erythropiotin dosage was calculated (weighted Erythropiotin=Erythropiotin dosage/weight) and the mean required dose was less than the required dose in group B and there was a highly statistically significant difference between the two groups. There was a significant negative correlation between the Thyrotropin level and hematocrit level and that leads us to conclude that the higher the Thyrotropin, the lower hematocrit will be and subsequently the higher Erythropiotin dose needed.

Conclusions: There is a relationship between Thyrotropin level even within normal reference range (in euthyroid state) on erythropoietin dose in end-stage renal disease patients on hemodialysis. In other words, the higher Thyrotropin level is, the more Erythropiotin dose needed. The required erythropoietin stimulating agent dose can be predicted by measuring Thyrotropin level.