Background. Various biomarkers and assays have been used for assessment of (anti)oxidant status in hemodialysis patients, including those intended for measurement of serum total (anti)oxidants, most often as a part of panel biomarkers. Methods. Serum (anti)oxidant status was measured in 32 chronically hemodialyzed patients and in 47 healthy persons, using two oxidations and three antioxidant assays. Results. The patients before the hemodialysis session have had higher values of total oxidants in comparison to the healthy persons, with a further increase during the hemodialysis. These findings were confirmed with both oxidation assays, but they differ in the percentage of increase and the statistical significance. All three antioxidant assays showed significantly higher values of the total serum antioxidants in the patients before the hemodialysis session in comparison to the healthy persons, and their significant decrease during the hemodialysis. However, the assays differ in the percentage of decrease, its statistical significance, and the correlations with uric acid. Conclusion. The variability of results of total (anti)oxidants which are obtained using different assays should be taken into account when interpreting data from clinical studies of oxidative stress, especially in complex pathologies such as chronic hemodialysis.

There was an improved control of all bone and mineral parameters in our dialysis units, following the publication of the CKD-MBD KDOQI guidelines. In order to improve the iPTH values, a more frequent use of low Ca dialysate (1.25 mmol/L) and of non-calcium-based phosphate binders in this small subset of patients should be implemented, as recommended by the guidelines. Individualization of the CKD-MBD management may be successful, even when newer treatment options are not available. Finally, the guidelines implementation process should be a continuous and self-monitored process, with the help of periodic surveys.

Abstract. Background: Disturbed oxidant/antioxidant status is involved in pathogenesis of anemia in end stage renal disease. There is evidence that vitamin E supplementation can increase blood hemoglobin in chronically hemodialyzed patients. However, the interindividual variation in response to the supplementation has not been fully addressed. Methods: 24 chronically hemodialyzed patients were supplemented with vitamin E (400 IU/day) in a period of two months. They had already been treated with erythropoiesis stimulating agents (ESA) and iron on a long-term basis, which was continued during the study period. A group of 20 healthy volunteers served as control subjects. Complete blood count, general biochemistry assays, the redox status by total thiols, oxidative stress by reactive oxygen metabolites, antioxidant status by biological antioxidant potential, and vitamin E (α- and γ- tocopherol) were measured before the start of supplementation, one month and two months later. Results: Overall, the vitamin E supplementation did not cause an increase of blood hemoglobin, hematocrit or red blood cells. However, 50 % of the patients with basal blood hemoglobin below 12.0 g/dL (N = 10) responded to the supplementation with its continuous increase. In addition, vitamin E exhibited a slight prooxidant effect only in the subgroup of patients with basal blood hemoglobin of ≥ 12.0 g/dL, two months after the start of supplementation (decreased total thiols: 300 ± 31 vs. 277 ± 36 µmol/L, p < 0.05; increased reactive oxygen metabolites: 183 ± 140 vs. 287 ± 112 CARR U, p > 0.05; decreased biological antioxidant potential: 2278 ± 150 vs. 2171 ± 126 µEq/L, p < 0.025), which coincided with their significantly increased serum α-tocopherol concentrations in comparison to the patients with basal blood hemoglobin below 12.0 g/dL (41.3 ± 7.2 vs. 59.9 ± 19.2 µmol/L, p < 0.025). Conclusions: When treated with ESA and iron on a long-term basis, the response to the vitamin E supplementation in chronically hemodialyzed patients is largely dependent on their basal blood hemoglobin and serum vitamin E concentrations.