Background: Hemodialysis with polymethylmetacrylate (PMMA) membrane dialyzers allows unique protein adsorption. New PMMA dialyzers should demonstrate equivalent protein adsorption, but improved hemocompatibility.

Introduction We previously reported the nutritional advantage of polymethylmethacrylate (PMMA) membranes to prevent the progression of malnutrition in dialysis patients. In this study, we examined whether a new PMMA dialyzer, NF-U, has advantages to improve the nutritional condition, patient-reported symptoms, and other clinical parameters in older dialysis patients. Methods We selected ten older chronic dialysis patients who were treated with NF-U for improving their worsening nutritional parameters and retrospectively evaluated nutrition and patient-reported symptoms. Patient-reported symptoms were surveyed by our original questionnaire including 20 items of symptom. Results Serum albumin concentration, geriatric nutritional risk index, and percent creatinine generation rate increased from 3.01 ± 0.16 to 3.25 ± 0.17 g/dL, 87.7 ± 5.8 to 91.4 ± 6.2, 100.2 ± 21.6 to 111.9 ± 20.9% at 1 and 4 months after switching to NF-U, respectively. For patient-reported outcomes, fatigue and the total score of patient-reported outcomes were improved after switching to NF-U. Conclusion Our results suggest that NF-U is a good choice for older dialysis patients to ameliorate their nutritional status and patient-reported outcomes.

Background and Aims Malnutrition is the most powerful prognostic factor in dialysis patients, and elder dialysis patients have a higher risk of malnutrition because of multiple comorbidities and daily inactivity. Hence, it is very important to set up a dialysis prescription for preventing progression of malnutrition. We reported nutritional advantage of polymethylmethacrylate (PMMA) membrane for preventing dialysis patients from the progression of malnutrition in the previous report. NF-U has been developed with better hemocompatibility and lesser albumin leakage during the dialysis session than conventional PMMA membranes. We studied additional advantages of NF-U on the nutritional status, patient-reported symptoms and other clinical parameters in elder dialysis patients. Method This study was a retrospective one. 10 elder chronic dialysis patients of greater than 75 years old were enrolled into the study; 5 males and 5 females, the mean age was 82.8 years old, and the average dialysis vintage was 11.2 years. NF-U were installed because of low albuminemia, dry weight (DW) loss and other signs of malnutrition. The previous membrane materials were polyether polymer alloy (6), vitamin E coated polysulfone (1), on-line HDF with polyethersulfone (2) and polysulfone (1). On-line HDF were performed in predilution with the substitution volume of 12L/hr. During the observation period the dialysis prescription except dialysis membrane was not changed. Serum albumin, β2MG, CRP, nPCR, GNRI, ％CGR, DW, CTR were compared one month and four month after the replacement with NF-U. In consideration of the seasonal variation of nutritional status, DW and CTR were compared with that of one year before the study. The changes in body composition were analyzed by Inbody770® (Inbody Japan, Tokyo, Japan)at three months before and after the replacement with NF-U. We also evaluated patient-reported subjective symptoms by our original tool as “Patient-oriented Dialysis (POD)” system three months before and after NF-U installation. Results Serum albumin increased from 3.0g/dl to 3.3g/dl. GNRI increased from 87.7 to 91.4. %CGR increased from 91.9% to 102.8%. No significant changes were observed in β2MG, CRP and nPCR. Although DW had continuously decreased from 52.7kg to 51.7kg before NF-U installation, DW increased from 52.0kg to 52.7kg by NF-U. CTR did not change. Muscle volume and body fat mass also increased. Regarding subjective symptoms, total POD score was significantly improved and especially dialysis related fatigue was remarkably reduced by NF-U. Conclusion The current study clearly showed that NF-U of a new PMMA membrane improved the nutritional status of elder dialysis patients with higher risk of malnutrition although the study was a limited retrospective one. Furthermore, NF-U also improved patient-reported subjective symptoms such as fatigue which was reported as a mortality risk factor and the most important patient’s outcome. We have not yet established a golden standard or parameter to set up dialysis prescriptions properly to elder dialysis patients. However, improvement of nutritional status and fatigue are one of the most important parameters to expect better outcome of them. We conclude that NF-U should be one of the best choices to treat elder dialysis patients.