Background: Little information is available regarding the type of dialyzer which results in good prognosis. This study is aimed at investigating the association between 7 types of dialyzers and 2-year mortality. Methods: We conducted a cohort study using data from a nationwide registry of the Japanese Society for Dialysis Therapy. Subjects were 136,676 patients on maintenance hemodialysis (HD) between 2009 and 2011 who underwent maintenance HD for at least 2 years and were treated with one of the following 7 types of high-performance membrane dialyzers: cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause 2-year mortality, adjusting for potential confounders. Results: Data were adjusted using basic factors, with PS as a reference group, and the hazard ratio (HR) was significantly higher in CTA, PMMA, PAN, and EVAL groups. Further data adjustment for Kt/V yielded the same results as were obtained from data adjusted for basic factors. After further adjustment for nutrition- and inflammation-related factors, HR was significantly lowered for the PES and PMMA groups compared with the PS group (HR 0.88; 95% CI 0.82-0.94 and HR 0.84 95% CI 0.76-0.93, respectively). After propensity score matching, HR for the PES and PMMA groups was significantly lowered compared with the PS group. Conclusions: The use of different membrane types may affect mortality. Further long-term prospective studies are needed to clarify whether the PES and PMMA membranes can improve prognosis.

Multiple 24-hour urine collections are necessary to adequately assess sodium and potassium intake. Here, we assessed kidney function decline for four years after baseline in relation to seven-time averaged 24-hour urinary sodium and potassium excretion (UNaV, UKV), their UNaV/UKV ratio, and their categorical combination in outpatients with chronic kidney disease (CKD). This retrospective cohort study was based on 240 outpatients with baseline CKD stages 3-5, baseline age 20 years or more (median age 72.0 years), and a median follow-up (with interquartile range) of 2.9 (1.4-4.0) years. Outcome was the percentage change in annual slope of estimated glomerular filtration rate (delta eGFR per year). In linear mixed models, percentage changes in delta eGFR per year were -3.26% (95% confidence interval -5.85 to -0.60), +5.20% (2.34 to 8.14), and -5.20% (-7.64 to -2.69), respectively, per one standard deviation increase in the seven-time averaged UNaV and UKV, and their UNaV/UKV ratio. Additionally, percentage changes per year in delta eGFR per year were -16.27% (-23.57 to -8.27) in the middle-to-high UNaV and low UKV group, compared with the low UNaV and middle-to high UKV group. Thus, our study reinforces the observation of opposite associations between GFR decline and urinary excretion rates of sodium (positive) and potassium (negative), respectively. Whether changes in dietary sodium and potassium intake slow GFR decline still requires further study.

Chronic kidney disease is a major risk factor for dementia, but the influence of hemodialysis itself on the development of dementia remains unclear. We previously reported that non-diabetic patients on maintenance hemodialysis have preserved cognitive function; hemodialysis removes blood amyloid β (Aβ), which is a major cause of Alzheimer’s disease in the brain; and the number of Aβ deposits in the postmortem brains of hemodialysis patients was significantly less compared to that in age-matched controls not undergoing hemodialysis. We aimed to evaluate the influence of hemodialysis on the development of dementia. We accessed the Japanese Society for Dialysis Therapy Renal Data Registry between December 31, 2009, and December 31, 2010. Dementia was identified in 120,101 patients undergoing maintenance hemodialysis. The association between hemodialysis duration and dementia risk was analyzed using logistic regression analysis. There was a significant decrease in the dementia risk with an increase in the hemodialysis duration, with odds ratios (95% confidence intervals) of 0.78 (0.74–0.82) and 0.88 (0.78–0.99) for every 10 years in non-diabetic and diabetic patients, respectively. However, in diabetic patients, the correlation between hemodialysis duration and dementia risk was not consistent. A longer hemodialysis duration was correlated with a lower dementia risk, but the correlation between hemodialysis duration and dementia risk in diabetic patients was much weaker and vaguer than that in non-diabetic patients. This finding does not appear to contradict greatly the assumption that the reduction in dementia risk with a prolonged hemodialysis duration in non-diabetic patients was caused not only by the survivor effect but also by hemodialysis itself.

Background: The expected remaining lifetime of dialysis patients in Japan was only reported in 2003 and has not been reported thereafter. From 2003 to the present, several new therapeutic agents have been introduced. These events may have improved outcomes for dialysis patients. Thus, expected remaining lifetime of dialysis patients in Japan was newly calculated in 2015. Methods: The Japanese Society for Dialysis Therapy Renal Data Registry database was used for analyses. From this database, the following three indexes were compiled: the number of surviving dialysis patients (198,125 males and 111,962 females) at the end of 2014 and the number of surviving (179,649 males and 101,758 females) and dead (18,044 males and 111,417 females) patients at the end of 2015. Based on these values, expected remaining lifetime at 1-year increment was calculated using the life table method. Results: Excerpts of the calculated expected remaining lifetimes of patients aged 60 years were as follows: 11.9 years for males and 14.1 years for females. These expected remaining lifetimes were 1.1 to 1.2 times as compared with those in 2003. Meanwhile, expected remaining lifetime of diabetic patients was 10.8 years for males and 12.5 years for females and that of nondiabetic patients was 13.0 years for males and 15.0 years for females. Conclusion: Expected remaining lifetime of dialysis patients in Japan in 2015 was 10–20% longer than that in 2003. These results suggest that advances in dialysis technologies during this 12-year period improved the survival rate of dialysis patients.

According to the annual survey of the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR) conducted at the end of 2018, there were a total of 339,841 patients receiving dialysis (hereinafter, dialysis patients) in Japan. The survey included questions regarding the presence/absence of dementia, the performance status (PS), and the exercise habits of individual patients. The survey revealed that 10.8% of all dialysis patients had dementia (1.8% in the age group of less than 65 years, 6.8% in the age group of 65–74 years, and 22.7% in the age group of 75 years or older). These prevalences of dementia were approximately equal to those estimated from the survey conducted in 2010. Regarding PS, the percentage of patients with lower activity levels tended to be relatively high among patients who were less than 15 years old and those who were 60 years old or older. Concerning the exercise habits of dialysis patients, the percentage of patients who were classified as “not at all or hardly” in response to the question about exercise habit was the highest (60–80%) of all the exercise habit classifications in each of the age groups analyzed.