Vitamin E supplementation by vitamin E-coated CAE dialysis membrane suppresses oxidative stress and inflammation.

Purpose The impact of different dialysis modalities on oxidative stress and inflammation and the factors implicated in this interrelationship have not been adequately studied. This study was designed to comparatively evaluate the effect of hemodialysis (HD) and peritoneal dialysis (PD) on oxidative stress and inflammatory biomarkers and to search for associated factors. Methods We studied 20 HD, 11 PD patients and 11 healthy controls. Calculations were based on total antioxidant capacity (TAC) and superoxide dismutase (SOD), by spectrophotometry, as oxidative stress biomarkers; and high sensitivity CRP (hs-CRP), lnterleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α), by ELISA, as inflammation biomarkers. Results HD and PD patients showed significantly increased levels of TAC, SOD and hs-CRP compared to healthy controls. No significant difference was observed in TNF-α and IL-6. Compared to HD patients, PD patients showed TNF-α levels that were increased, although non-significantly and significantly higher homocysteine (Hcy). No differences were observed for IL-6, hs-CRP, TAC and SOD. In HD patients, significant positive correlations were found between intact parathyroid hormone (iPTH) and TNF-α, and between uric acid (UA) and TAC. β2-microglobulin (β2M) was negatively correlated with TAC, total cholesterol (TC) positively with TNF-α and negatively with SOD, and triglycerides (TG) correlated positively with TNF-α. In PD patients, TG correlated positively with TNF-α, HDL-cholesterol negatively with TNF-α, LDL-cholesterol negatively with SOD, and β2M negatively with SOD. Conclusions HD and PD patients show similar degrees of inflammation and oxidative stress activation. Factors such as UA, iPTH, β2M and lipid profile correlate to oxidative stress and inflammatory biomarkers in both HD and PD patients.

No abstract

Background Dietary phosphorus restriction, oral administration of phosphorus binders, and dialysis are the main strategies to control hyperphosphatemia in patients with stage 5 chronic kidney disease. Aluminum hydroxide (AH) and calcium carbonate, the most commonly used phosphorus binders, have serious disadvantages, such as aluminum toxicity and hypercalcemia. Sevelamer hydrochloride (SH) is a relatively new nonabsorbed calcium- and aluminum-free phosphorus binder. The present study was designed to evaluate the efficacy of SH in the control of hyperphosphatemia and its effect, compared to AH, on serum lipid parameters in patients on continuous ambulatory peritoneal dialysis (CAPD). Methods 30 stable patients on CAPD were included in an open-label, randomized crossover study. After a 2-week phosphorus binder washout period, 15 patients (group I) were administered SH for 8 weeks and in the remaining patients (group II), AH was introduced (phase A). After a new 2-week washout period, patients crossed over to the alternate agent for another 8 weeks (phase B). Results There were similar reductions in serum phosphorus levels over the course of the study with both agents: by 1.18 ± 0.07 mg/dL (0.38 ± 0.03 mmol/L) with SH and by 1.25 ± 0.15 mg/dL (0.40 ± 0.05 mmol/L) with AH in phase A ( p = NS), and by 1.35 ± 0.25 mg/dL (0.43 ± 0.08 mmol/L) with AH and by 1.23 ± 0.80 mg/dL (0.39 ± 0.25 mmol/L) with SH in phase B ( p = NS). Moreover, SH administration was associated with a 10.5% ± 9.4% and a 20.1% ± 6.8% fall in total cholesterol ( p < 0.05) and low-density lipoprotein cholesterol ( p < 0.001) in phase A, and 11.9% ± 7.2% ( p < 0.05) and 21.5% ± 2.4% ( p < 0.001), respectively, in phase B. In both phases of the study, AH administration was not followed by a significant change in serum lipid parameters. Conclusion Sevelamer hydrochloride is a well-tolerated alternative to calcium- or aluminum-containing phosphorus binder in the control of serum phosphorus in CAPD patients. Furthermore, SH improves the lipid profile in these patients.

Background/Aim: We investigated the potential role of the membrane type on phosphate kinetics. Methods: Six patients on dialysis (HD) were studied using modified cellulose (Hemophan), ethylene-vinyl alcohol (EVAL) and polyacrylonitrile (PAN). Total (TPR), extracellular (EPR) and intracellular (IPR) phosphate removal and effective dialyzer phosphate clearance (K_d) were determined by the DDQ method. The intercompartment transfer coefficient (K_C) was calculated using a mathematical model. Erythrocyte phosphate (P_ERY) and 2,3-biphosphoglycerate (2,3-BPG) concentrations were determined before and after HD. Results: TPR was 1.2 ± 0.4, 1.10 ± 0.4 and 1.09 ± 0.4 g with Hemophan, EVAL and PAN, respectively (p = n.s.). EPR and IPR were independent of membrane type. There was no difference in K_C between membranes (321 ± 70, 338 ± 92 and 341 ± 83 ml/min, respectively). The P_ERY and 2,3-BPG remained statistically insignificant for all membranes. Conclusion: Our results show that the type of membrane does not influence the kinetics of phosphate during dialysis, neither in the transfer from plasma to dialysate nor from the intra- to the extracellular compartment.