Low-flux Group Research Articles

Diurnal patterns of salivary cytokines differentially correlate with greater fluctuations in cortisol and diet composition: A pilot study

Chronic stress and elevated cortisol are associated with adverse metabolic profiles and lifestyle patterns, systemic low-grade inflammation, and increased chronic disease risk; however, it is less clear how the degree of cortisol fluctuations impacts these parameters. Adult men and women (18-70y) were recruited to participate in a 5-day observational study, in which they underwent a baseline health and body composition assessment, completed 5-day diet, exercise, and stress records, and provided saliva samples in the morning, afternoon, and evening to measure fluctuations in cortisol, interleukin-1β (IL-1β), and IL-6. Degree of cortisol variability over the 5-day period (highest cortisol measure - lowest cortisol measure) was used to classify subjects into high (n = 9) and low (n = 9) cortisol fluctuation groups. Participants with greater fluctuations in salivary cortisol had higher salivary cortisol concentrations on average, which was attributed to higher maximal and morning cortisol. A greater proportion of individuals with higher cortisol flux worked in first responder/emergency professions, and exhibited minimal dietary pattern differences compared to those with low cortisol flux. While body fat percentage and mass positively correlated with minimum salivary cortisol measures, body composition and blood pressure did not differ between low vs. high salivary cortisol flux groups. Interestingly, we observed diurnal patterns of salivary IL-1β concentrations, with higher IL-1β in the morning, and greater afternoon IL-1β in the high cortisol flux group compared to the low cortisol flux group. Independent of cortisol flux, waking satiety and intake patterns of dietary nutrients and food groups/type differentially correlated with salivary cytokine concentrations in a time of day-dependent manner. Our findings suggest that greater fluctuations in cortisol are associated with distinct diurnal salivary cortisol and IL-1β concentrations but minimal lifestyle and dietary factors, whereas dietary patterns are strongly and differentially associated with salivary cytokine profiles.

Medium Cut-Off versus Low-Flux Dialyzers in Hemodialysis Patients with COVID-19: Clinical Outcomes and Reduction in Interleukin-6

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has caused extensive morbidity and mortality worldwide. Hemodialysis (HD) patients are both vulnerable to COVID-19 infection and tend to suffer greater disease severity and mortality. This retrospective study aimed to compare medium cut-off (MCO) and low-flux (LF) membrane dialyzers in terms of interleukin-6 (IL-6) reduction, change in inflammatory state, intradialytic complications, and mortality in chronic HD patients with COVID-19. Method: HD patients with a confirmed COVID-19 infection were admitted to the hospital for 10–14 days and underwent HD at the COVID-HD unit. Choice of dialyzer membrane used (MCO vs. LF) depended on the primary nephrologist(s). We collected data on demographics, baseline characteristics, laboratory results, diagnosis, treatments, HD prescription, hemodynamic status during HD, and mortality at 14 and 28 days after. Results: IL-6 reduction ratio (RR) in the MCO group was 9.7 (interquartile range, 71.1) percent, which was significantly higher than that of the LF group (RR, −45.7 [interquartile range, 70.2] percent). The incidence rate of intradialytic hypotension in the MCO group was 3.846 events per 100 dialysis hours (95% confidence interval [CI], 1.954–6.856), which was significantly lower than that of the LF group (9.057; 95% CI, 5.592–13.170). Overall, mortality was not significantly different between the two groups. Conclusion: The MCO membrane was more effective in removing IL-6 and was better tolerated than the LF membrane. Large, randomized controlled trials are required to confirm the relative benefits of the MCO membrane, especially mortality. However, due to the COVID-19 pandemic, our results suggest that the MCO membrane may be beneficial in chronic HD patients with COVID-19.

MO915: Factors Related to Chronic Kidney Disease–Associated Pruritus in Patients Undergoing Haemodialysis and its Effects on Quality of Life

Abstract BACKGROUND AND AIMS Chronic kidney disease-associated pruritus (CKD-aP) is an often overlooked, common and debilitating problem for patients undergoing haemodialysis. Although the prevalance of CKD-aP has decreased over the years, it continues to be a problem associated with quality of life impairment, sleep disturbances, increased mortality and morbidity. With this study, we aim to investigate factors related to CKD-aP and its impact on patients’ quality of life. METHOD We conducted a cross-sectional study of in-centre HD patients in the city of Eskişehir, Turkey. A total of 298 patients undergoing HD for >3 months were enrolled in the study. We analysed demographic characteristics, routine laboratory values, interdialytic weight gain, residual urine output, xerosis, 5D itch scale scores (multidimensional itch-related questionnaire), VAS score (ranging from no itching to the worst itching imaginable) and LANSS score (neuropathic pain assessment scale) of enrolled patients. RESULTS Mean age of 298 patients was 64.6 ± 13.2 and 52% of patients were male. Pruritus prevalence in the study group was 45%. The 5D scores were higher among patients with < 200 mL residual urine output versus patients with >500 mL residual urine output (P = .034). The 5D scores were higher among patients with xerosis (P < .001). The 5D scores were again higher among patients with a LANSS score of ≥ 12 (P < .001). The 5D scores were lower among the low-flux membrane group versus the high-flux membrane group (P = .001). The 5D scores were correlated with interdialytic weight gain (r = 0.124; P = .033), Kt/V (r = –0.228; P < .001), ALT levels (r = 0.135; P = .02), total iron binding capacity (r = .13; P = .025) and VAS scores (r = 0.969; P < .001). There were no statistically significant correlations between 5D scores and age, body mass index, HD duration, creatinine, BUN, calcium, phosphorus, calcium-phosphorus product (CAxP) and other routinely tested laboratory values. CONCLUSION In our study, we identified residual urine output, xerosis, neuropathic pain, HD membrane type, interdialytic weight gain, Kt/V, ALT and TIBC as factors related to CKD-aP. The strong relationship between itch severity and neropathic pain scores was especially notable. More research in this field may be beneficial for identifying new therapeutic targets for CKD-aP.

Abbreviated scan protocols to capture 18F-FDG kinetics for long axial FOV PET scanners.

Kinetic parameters from dynamic 18F-fluorodeoxyglucose (FDG) imaging offer complementary insights to the study of disease compared to static clinical imaging. However, dynamic imaging protocols are cumbersome due to the long acquisition time. Long axial field-of-view (LAFOV) PET scanners (> 70cm) have two advantages for dynamic imaging over clinical PET scanners with a standard axial field-of-view (SAFOV; 16-30cm). The large axial coverage enables multi-organ dynamic imaging in a single bed position, and the high sensitivity may enable clinically routine abbreviated dynamic imaging protocols. In this work, we studied two abbreviated protocols using data from a 65-min dynamic 18F-FDG scan: (A) dynamic imaging immediately post-injection (p.i.) for variable durations, and (B) dynamic imaging immediately p.i. for variable durations plus a 1-h p.i. (5-min-long) datapoint. Nine cancer patients were imaged on the Biograph Vision Quadra (Siemens Healthineers). Time-activity curves over the lesions (N = 39) were fitted using the Patlak graphical analysis and a 2-tissue-compartment (2C, k4 = 0) model for variable scan durations (5-60min). Kinetic parameters from the complete dataset served as the reference. Lesions from all cancers were grouped into low, medium, and high flux groups, and bias and precision of Ki (Patlak) and Ki, K1, k2, and k3 (2C) were calculated for each group. Using only early dynamic data with the 2C (or Patlak) model, accurate quantification of Ki required at least 50 (or 55) min of dynamic data for low flux lesions, at least 30 (or 40) min for medium flux lesions, and at least 15 (or 20) min for high flux lesions to achieve both 10% bias and precision. The addition of the final (5-min) datapoint allowed for accurate quantification of Ki with a bias and precision of 10% using only 10-15min of early dynamic data for either model. Dynamic imaging for 10-15min immediately p.i. followed by a 5-min scan at 1-h p.i can accurately and precisely quantify 18F-FDG on a long axial FOV scanner, potentially allowing for more widespread use of dynamic 18F-FDG imaging.

Incidence of intradialytic hypertension in hemodialysis patients in Beheira governorate and effect of high flux versus low flux dialysis on it

Abstract Background Intradialytic hypertension (IDH) is a common complication of hemodialysis (HD) that is under-recognized and its significance is underappreciated. No standard definition of IDH exists. As a unifying criteria for the diagnosis of IDH has not been proposed, the focus of this review will be on systolic blood pressure (SBP) rise = 10 mmHg at = 4 over six consecutive sessions. IDH is estimated at 5–15% of HD patients. IDH has been associated with poor clinical outcomes in HD patients including increased hospitalizations, higher ambulatory blood pressure (BP), cardiovascular morbidity, and mortality. Aim of the Work To detect the incidence of IDH in HD patients in Beheira governorate and to compare the effect of high flux versus low flux dialysis on it. Patients and Methods This study was conducted on 200 patients on maintenance HD from different HD units in Beheira governorate. The patients were divided into two groups: Group 1: 100 patients on HD with high flux dialyzers and Group 2: 100 patients on HD with low flux dialyzers. Results: Incidence of IDH in HD patients in Beheira governorate was 23.5% at the start, 21% after one month and 13% after three months duration. Results of our study demonstrated that there were no significant differences between both groups as regards effect of high-flux vs low-flux dialysis on IDH after one month and at the end of the study (P > 0.05), but there was a significant decrease in number of IDH patients after one month duration and after three months in both high-flux and low-flux dialysis patients. In our study, there was significant improvement in the form of reductions in all of pre-dialysis BUN, post-dialysis BUN, serum creatinine levels and serum IPTH levels at the end of the study in high flux group compared to low flux group. Finally, our results showed significant improvement in serum hemoglobin levels in high flux group by the end of the study in contrast to the low flux group. Conclusion No significant difference in the effect of high flux versus low flux dialysis on IDH, but there was significant improvement in all of pre-dialysis BUN, post-dialysis BUN, serum creatinine levels and serum IPTH levels by the end of the study in the high flux group compared to the low flux group.

Dialyzer Classification and Mortality in Hemodialysis Patients: A 3-Year Nationwide Cohort Study.

Background: Dialyzers are classified as low-flux, high-flux, and protein-leaking membrane dialyzers internationally and as types I, II, III, IV, and V based on β2-microglobulin clearance rate in Japan. Type I dialyzers correspond to low-flux membrane dialyzers, types II and III to high-flux membrane dialyzers, and types IV and V to protein-leaking membrane dialyzers. Here we aimed to clarify the association of dialyzer type with mortality.Methods: This nationwide retrospective cohort study analyzed data from the Japanese Society for Dialysis Therapy Renal Data Registry from 2010 to 2013. We enrolled 238,321 patients on hemodialysis who were divided into low-flux, high-flux, and protein-leaking groups in the international classification and into type I to V groups in the Japanese classification. We assessed the associations of each group with 3-year all-cause mortality using Cox proportional hazards models and performed propensity score matching analysis.Results: By the end of 2013, 55,308 prevalent dialysis patients (23.2%) had died. In the international classification subgroup analysis, the hazard ratio (95% confidence interval) was significantly higher in the low-flux group [1.12 (1.03–1.22), P = 0.009] and significantly lower in the protein-leaking group [0.95 (0.92–0.98), P = 0.006] compared with the high-flux group after adjustment for all confounders. In the Japanese classification subgroup analysis, the hazard ratios were significantly higher for types I [1.10 (1.02–1.19), P = 0.015] and II [1.10 (1.02–1.39), P = 0.014] but significantly lower for type V [0.91 (0.88–0.94), P < 0.0001] compared with type IV after adjustment for all confounders. These significant findings persisted after propensity score matching under both classifications.Conclusions: Hemodialysis using protein-leaking dialyzers might reduce mortality rates. Furthermore, type V dialyzers are superior to type IV dialyzers in hemodialysis patients.

Effect of High-Flux versus Low-Flux Dialysis on the Rate of Bacteremia in Hemodialysis Patients

Bacteremia in dialysis patients is a major risk factor of mortality. The aim of this study was to assess the effectiveness of dialysis with high-flux versus low-flux dialyzer regarding risk of bacteremia in dialysis patients. This was a retrospective cohort study that included dialysis patients who underwent dialysis therapy at old dialysis center where old low-flux dialyzers were used and the new dialysis center where high-flux dialyzers were used. The rate of positive culture was more in high-flux group (37.0%) compared to low-flux group (24.5%), although the difference was not statistically significant (P = 0.13). The vascular access was mostly permanent catheter in high-flux group compared to low-flux group (48.9% vs. 28.6%, respectively; P = 0.06), while arteriovenous (AV) fistula was more prominent in low-flux group compared to high-flux group (65.3% vs. 47.8%, respectively; P = 0.06). This was reflected in the type of bacteria, which was mostly from Gram-positive family (Staphylococcus). The results showed higher risk of bacteremia in high-flux group as compared to low-flux group; however, permanent catheters were more prominent in high-flux group.

Medium Cut-Off Dialysis Membranes: Can They Have Impact on Outcome of COVID-19 Hemodialysis Patients?

Introduction: Severe acute respiratory syndrome coronavirus-2 may lead to high levels of expression of inflammatory cytokines. Medium cut-off (MCO) membranes may make greater clearances for large-middle molecules (including cytokines) than low-flux (LF) membranes. In this study, we aimed to evaluate the impact of MCO membranes on outcome of COVID-19 patients on hemodialysis (HD). Methods: Sixty COVID-19 HD patients were included in this study. The patients were categorized into 2 groups regarding type of HD membranes. Clinical data were taken from medical records. Results: Initial crp and ferritin levels, which are surragates of cytokine storm and severity of disease in COVID-19, were significantly higher in MCO membrane group compared to LF group (p = 0.037 and 0.000, respectively). Although there were more patients with severe disease in MCO group, there were no significant differences regarding need for intensive care unit and death. Conclusion: It may be an option to use MCO membranes in HD patients with COVID-19 in order to reduce cytokine levels and prevent cytokine storm.

Effect of High Flux Hemodialysis versus Hemodiafiltration on Metabolic Status in Hemodialysis Patients

Background: Hemodiafiltration (HDF) is a newly developed renal replacement therapy blood purification technology with more advantageous effects on hemodynamic stability and better removal of B2 microglobulin and phosphorous Objective: The aim of this study is to compare effect of high flux (HF), low flux (LF) dialysis membranes and hemodiafiltration (HDF) on the metabolic status in hemodialysis patients and quality of life of those patients. Patients and Methods: This study included 60 patients more than18 years old, clinically stable with end stage renal disease on regular HD for at least three years (3 yrs), selected from HD unit in (Kobry El Kobba Military Nephrology Hospital) in the period from March 2018 to September 2018. The patients were divided into three groups equally. Group I: 20 patients on low flux dialyzer, Group II: 20 patients on high flux dialyzer, Group III: 20 patients on hemodiafiltration. Results: There was a highly significant decrease in iPTH, B2 microglobulin and Phosphorous in patients received HDF (363.80±149.04, 8.79±7.22 and 4.31±0.74 respectively in comparison with patients received HF hemodialysis (540.10±242.55, 20.47±3.97and 4.58±1.07 respectively) and patients received LF hemodialysis (725.95±270.01, 36.60±7.22 and 5.73±1.34 respectively).Also, there were a highly significant increase in urea reduction ratio in HDF group compared to HF and LF groups (80.43±7.46, 76.03±9.55 and 65.81±7.42 respectively. Conclusion: Hemodiafiltration is the most effective dialysis technique than high flux and low flux dialysis membrane in removal of medium sized molecule and improvement of quality of life.

SUN-255 THE EFFECT OF HEMODIALYSIS ON HscTnI LEVELS AMONG ASYMPTOMATIC CKD PATIENTS IN A TERTIARY HOSPITAL IN DAVAO CITY

Mild chest pains or discomforts occur in 1 to 4% of Chronic Kidney Disease (CKD) patients on hemodialysis (HD). Cardiac Troponins play a pivotal role in the diagnosis of Acute Coronary Syndrome (ACS). Chronic HD patients have increased cardiac troponins that may not be due to ACS, but subclinical myocardial damage. Interpretation of cardiac troponin assay among these patients constitutes a big challenge. Equally important is to know the behavior of troponins during HD. To date, it has not been clearly elucidated whether HD can affect the level of cardiac troponins1,2,3. Literatures showed that HD decreases the level of cardiac troponins immediately post procedure2,5, while others have shown an increase6. Such ambiguity makes clinicians more confused in interpreting cardiac troponin among CKD patients. This study aims to determine the effect of HD in high sensitivity cardiac troponin I (HscTnI) levels among CKD patients and identify factors that are potential sources of variability that can affect the interpretation of HscTnI. This is a prospective study conducted in a tertiary hospital. 44 asymptomatic CKD patients on maintenance HD were enrolled. Sampling was purposive. Exclusion criteria included HD vintage of less than 6 months, critical illness, infection, myocardial infarction in the last 30 days, and coronary angioplasty or cardiac surgery in the last 12 months. Pre-HD and immediate post-Hd HscTnI were measured using HscTnI ARCHITECTSTAT assay by Abbott. Demographic data, ultrafiltration coefficient of membranes either hi-flux or low-flux, and the frequency of membrane dialyzer reuse were noted. 23/44 (52%) of the study population had elevated pre-HD HscTnI based on the cut-off range provided by the manufacturer. Comparative analysis using paired T-test to determine significant difference between pre- and post-HD HscTnI showed that pre-HD HscTnI is higher (M=60.96, SD=75.64) than post-HD levels (M=60.65, SD=78.06), with a 0.16 ng/L difference. Paired T-test result showed that the difference is not significant (p value=0.9) at 5% level of significance. We regrouped patients according to their type of membrane dialyzer (Hi-flux and Low-flux). Many from low-flux group had decreased HscTnI post-HD than in the hi-flux group, contrary to what was expected. Hi-Flux membranes are supposed to clear macromolecules better. Further investigation found that most in the hi-flux group reused their dialyzer membranes 3-6x, while most membranes in the low-flux group were new. Analysis using Pearson Product Moment Correlation revealed a significant correlation between the number of usage of dialyzer to the change in the level of HscTnI post HD (Table 3). A comparative analysis using T-test for two proportions also found a significant correlation between single use membrane dialyzer and decrease in the level of HscTnI post-HD. Hemodialysis, in general, did not significantly affect the levels of HscTnI. Frequency of membrane reuse is a factor that affects HD performance and clearance of HscTnI. The more frequency of dialyzer reuse, the lesser the clearance of HscTnI.

Effect of High Flux Versus Low Flux Hemodialysis on Some Cardiovascular Risk Factors in Egyptian Children with End Stage Renal Disease.

Background Cardiovascular disease remains as the main cause of mortality in children with end stage renal disease (ESRD).Among the cardiovascular risk factors, dyslipidemia and inflammation are of great importance as they are both prevalent and modifiable risk factors. We aim to evaluate the effect of permeability of low-flux versus high-flux dialyzer on such 2 factors in children on regular hemodialysis (HD). Patients and Methods 48 children with ESRD were randomized into 2 groups. Group A used low-flux dialyzer, group B used high-flux dialyzer for 6 months. An initial and 6th month blood samples for lipid profile, serum albumin and serum high sensitivity CRP (hs CRP) were obtained. Statistical analysis was done. Results In the high flux group, there was a statistically significant difference in total cholesterol, HDL-cholesterol, triglyceride and hs CRP levels after 6 months when compared to baseline values of the same group, while LDL cholesterol and serum albumin showed no significant change. In the low flux group, results after 6 months didn’t show significant change in previously mentioned parameters when compared with its baseline values of the same group. Comparing these parameters between the 2 groups at 6 months, shows that high flux group has significantly lower total cholesterol, triglyceride, and hs CRP levels. Conclusion This study has demonstrated for the first time improvement of some markers of dyslipidemia and inflammation by using high-flux HD in children with ESRD. These results suggest that high-flux dialysis may benefit such young suffering population by reducing the atherogenic risk, cardiovascular morbidity and mortality.

Comparison the effect of high flux and low flux dialyzer on quality of life in hemodialysis patients; a clinical trial

Introduction: End-stage renal disease (ESRD) is a worldwide public health problem. ESRD reduces health-related quality of life. Quality of life is an important determinant in the mortality and morbidity of hemodialysis patients. However, several studies have suggested that high flux dialyzers increase dialysis adequacy and reduce mortality and morbidity in these patients. Objectives: This study aimed to investigate the effects of high flux and low flux dialyzers on the quality of life in hemodialysis patients. Patients and Methods: In this clinical trial, 93 patients who met the inclusion criteria were randomly assigned to two groups of high flux and low flux dialyzers. Before intervention, both groups filled demographic and quality of life questionnaires. They were undergone dialysis with two dialyzers (one group by high flux and another by low flux) three times a week for 6 weeks. Then quality of life questionnaire was filled by both groups once again. Results: The overall quality of life score was not significantly different in both groups before intervention (P=0.121). After intervention, however, high flux group attained a significantly higher mean score (54 ± 10.4) than low flux group (43.89 ± 11.64) (P&lt;0.001). Conclusion: According to the results of this study, the use of high flux dialyzers can be a useful method to increase the quality of life in hemodialysis patients.

Serum cardiac troponin T and effective blood flow in stable extracorporeal dialysis patients.

Purpose We examined the association between extracorporeal dialysis (ED)-related effective blood flow (eQB) and serum cardiac troponin T (cTnT) as a possible indicator of silent myocardial damage in stable ED patients.MethodsIn a cross-sectional study, cTnT was determined in 247 ED patients dialyzed using stable eQB and dialysate flow (QD). In a prospective study, 91 patients were switched from low-flux (LF) to high-flux (HF) hemodialysis (HD), and subsequently, the eQB increased, and the QD decreased; 65 patients continued LF-HD with stable eQB and QD. Clinical/laboratory evaluations were performed at 0, 15, 36, and 53 weeks from the start of the study.ResultsIn the cross-sectional study, the main cTnT predictors were dialysis vintage, age, eQB, phosphorus, and C-reactive protein. Patients with cTnT levels in the highest quartile were excluded from the analysis, and subjects dialyzed with eQB ≤316 ml/min exhibited lower cTnT levels compared with patients dialyzed with higher eQB (P = 0.002). The all-cause and cardiac mortality rates of 154 patients, without changes in ED modality for up to 42 months, were associated with the initial cTnT concentrations but not with the initial eQB. In the prospective study, higher values for eQB and cTnT were observed during HF-HD at weeks 36 (P = 0.045) and 53 (P = 0.01) of the present study. The initial cTnT, ∆eQB, and ∆albumin influenced the ∆cTnT. The all-cause and cardiac mortality rates were not different between LF and HF groups at 21 months after the prospective study was completed.ConclusionIn stable ED patients, higher eQB rates and QB/QD values might contribute to silent myocardial injury, particularly in patients with lower cTnT levels, but do not affect the outcome of ED patients.Electronic supplementary materialThe online version of this article (doi:10.1007/s11255-015-1165-z) contains supplementary material, which is available to authorized users.

Cystatin C: An alternative dialysis adequacy marker in high flux hemodialysis.

The conventional, low flux (LF) dialyzer allows the removal of small molecular solutes like urea and creatinine. High flux (HF) dialyzers allow the effective removal of middle molecules (MM) as well, and are associated with reduced hemodialysis-related morbidity and mortality. Cystatin C has attractive characteristics as a representative MM. The aim of this study was to determine cystatin C reduction ratio (CysCRR) in both LF and HF groups and to compare it with other markers of dialysis adequacy. Thirty-seven patients were subjected to both LF and HF hemodialysis 2 weeks apart. Serum urea, creatinine and cystatin C were measured pre- and post-dialysis. Cystatin C was measured by latex-enhanced immunoturbidimetry. Urea and creatinine reduction ratios were 72.3 ± 14.7% and 62.5 ± 13%, respectively in the LF group. The CysCRR was −9.7 ± 6.7% and 29.2 ± 11% in LF and HF hemodialysis, respectively. The statistically significant decrease in CysCRR in the HF group shows the effective clearance of MM by HF dialyzers. Hence, CysCRR could be applied to measure the MM clearance in HF hemodialysis. This study highlights the significance of cystatin C as an important dialysis adequacy marker replacing the conventional markers such as urea and creatinine in HF hemodialysis. Among the middle molecules cystatin C scores over beta-2 microglobulin.

Effect of dialysis dose and membrane flux on hemoglobin cycling in hemodialysis patients.

Many studies found that hemoglobin (Hb) fluctuation was closely related to the prognosis of the maintenance hemodialysis patients. We investigated the association of factors relating dialysis dose and dialyzer membrane with Hb levels. We undertook a randomized clinical trial in 140 patients undergoing thrice-weekly dialysis and assigned patients randomly to a standard or high dose of dialysis; Hb level was measured every month for 12 months. In the standard-dose group, the mean (±SD) urea reduction ratio was 65.1% ± 7.3%, the single-pool Kt/V was 1.26 ± 0.11, and the equilibrated Kt/V was 1.05 ± 0.09; in the high-dose group, the values were 73.5% ± 8.7%, 1.68 ± 0.15, and 1.47 ± 0.11, respectively. The standard deviation (SD) and residual SD (liner regression of Hb) values of Hb were significantly higher in the standard-dose group and low-flux group. The percentage achievement of target Hb in the high-dose dialysis group and high-flux dialyzer group was significantly higher than the standard-dose group and low-flux group, respectively. Patients undergoing hemodialysis thrice weekly appear to have benefit from a higher dialysis dose than that recommended by current KDQQI (Kidney Disease Qutcome Quality Initiative) guidelines or from the use of a high-flux membrane, which is in favor of maintaining stable Hb levels.

The impact of high-flux dialysis on mortality rates in incident and prevalent hemodialysis patients

Background/AimsThe effect of high-flux (HF) dialysis on mortality rates could vary with the duration of dialysis. We evaluated the effects of HF dialysis on mortality rates in incident and prevalent hemodialysis (HD) patients.MethodsIncident and prevalent HD patients were selected from the Clinical Research Center registry for end-stage renal disease (ESRD), a Korean prospective observational cohort study. Incident HD patients were defined as newly diagnosed ESRD patients initiating HD. Prevalent HD patients were defined as patients who had been receiving HD for > 3 months. The primary outcome measure was all-cause mortality.ResultsThis study included 1,165 incident and 1,641 prevalent HD patients. Following a median 24 months of follow-up, the mortality rates of the HF and low-flux (LF) groups did not significantly differ in the incident patients (hazard ratio [HR], 1.046; 95% confidence interval [CI], 0.592 to 1.847; p = 0.878). In the prevalent patients, HF dialysis was associated with decreased mortality compared with LF dialysis (HR, 0.606; 95% CI, 0.416 to 0.885; p = 0.009).ConclusionsHF dialysis was associated with a decreased mortality rate in prevalent HD patients, but not in incident HD patients.

The Impact of Membrane Permeability and Dialysate Purity on Cardiovascular Outcomes

The effects of high-flux dialysis and ultrapure dialysate on survival of hemodialysis patients are incompletely understood. We conducted a randomized controlled trial to investigate the effects of both membrane permeability and dialysate purity on cardiovascular outcomes. We randomly assigned 704 patients on three times per week hemodialysis to either high- or low-flux dialyzers and either ultrapure or standard dialysate using a two-by-two factorial design. The primary outcome was a composite of fatal and nonfatal cardiovascular events during a minimum 3 years follow-up. We did not detect statistically significant differences in the primary outcome between high- and low-flux (HR=0.73, 95% CI=0.49 to 1.08, P=0.12) and between ultrapure and standard dialysate (HR=0.90, 95% CI=0.61 to 1.32, P=0.60). Posthoc analyses suggested that cardiovascular event-free survival was significantly better in the high-flux group compared with the low-flux group for the subgroup with arteriovenous fistulas, which constituted 82% of the study population (adjusted HR=0.61, 95% CI=0.38 to 0.97, P=0.03). Furthermore, high-flux dialysis associated with a lower risk for cardiovascular events among diabetic subjects (adjusted HR=0.49, 95% CI=0.25 to 0.94, P=0.03), and ultrapure dialysate associated with a lower risk for cardiovascular events among subjects with more than 3 years of dialysis (adjusted HR=0.55, 95% CI=0.31 to 0.97, P=0.04). In conclusion, this trial did not detect a difference in cardiovascular event-free survival between flux and dialysate groups. Posthoc analyses suggest that high-flux hemodialysis may benefit patients with an arteriovenous fistula and patients with diabetes and that ultrapure dialysate may benefit patients with longer dialysis vintage.

The Relationship of NT-proBNP and Dialysis Parameters with Outcome of Incident Haemodialysis Patients: Results from the Membrane Permeability Outcome Study

Background/Aims: The association of raised levels of natriuretic peptides with elevated risk of mortality was investigated in the present analysis of the Membrane Permeability Outcome study. Methods: N-terminal probrain type natriuretic peptide (NT-proBNP) was measured in 618 incident haemodialysis patients, randomised to either high-flux or low-flux. Characteristics of patients with NT-proBNP levels below or above the median were descriptively analysed and survival analysis was performed. Results: Median NT-proBNP value was 2,124 pg/ml, with 1,854 pg/ml in the high-flux and 2,919 pg/ml in the low-flux group. Survival probability was lowest in patients with both a history of cardiovascular disease and NT-proBNP values above the median (p < 0.001). A multivariate Cox proportional hazard model showed interaction between presence of cardiovascular diseases and NT-proBNP levels above the median. Conclusions: NT-proBNP is an independent predictor of mortality also in incident haemodialysis patients. Lower concentrations associated with high-flux dialysis suggest a possible biological link to improved survival in this group.

Contribution of High Flux Membranes to the Therapy of Uremia‐Associated Dyslipidemia

Cardiovascular diseases are the leading causes of mortality in hemodialysis patients. Uremia induced hypertriglyceridemia; increased levels of lipoprotein remnants and low high-density lipoprotein are the main features of cardiovascular risk factors. Also, elevated oxidative stress and inflammation are the main contributors of endothelial dysfunction. Even statin based interventional trials failed to improve mortality in dialysis patients, and different treatment options have been proved to be useful. We aimed to evaluate the effect of dialyzer type on uremia-associated dyslipidemia and endothelial dysfunction. In total 312 patients were enrolled. The initial and 6(th) month blood samples were obtained from the non-arteriovenous fistula arm on the day before the first hemodialysis session of the week. Flow mediated dilatation of the patients was measured from the same arm before obtaining the blood samples. Patients were on hemodialysis therapy for 76.43 ± 52.7 months. According to their dialyzer type, there has been a statistically significant improvement noted in terms of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and triglyceride levels. The flow mediated dilatation of the patients are measured as 4.3 ± 0.5 and 4.4 ± 0.4 in baseline measurements of the low flux and high flux groups, respectively. Sixth month values of the patients were measured as 4.34 ± 0.4 and 4.62 ± 0.6. The improvement in low flux groups was not statistically significant but in the high flux group the endothelial dysfunction was significantly improved. Our results show that high-flux dialyzers improved dyslipidemia and endothelial dysfunction in hemodialysis patients. These findings provide a new insight on the selection of high efflux in hemodialysis.

Uraemic toxins versus volume and water as the major factor that matters with dialysis

In this pro-con debate, we will analyse the relevance of data supporting the prime role of uraemic toxins versus salt and volume overload as the main driver for the impressive mortality and morbidity characteristic of any end-stage re- nal disease patient. Firstly, we are going to review the circumstantial evidence and associated studies/clinical observational data which only weakly suggest that uraemic solutes are indeed linked to damage to the body and its constituents, especially the car- diovascular (CV) system. At the same time, we will equally thoroughly discuss the 'fact' that decreasing salt and fluid load is essential for any dialysed patient. Evidence in favour of a prominent role for uraemic toxins is appealing from a pathophysiological point of view, but unfortunately is mis- leading in real life practice. Evidence in favour of salt and water reduction is overwhelmingly stronger. This difference in apparent evidence strength notwith- standing the weaker support for uraemic toxins does not take away from clinical importance of minimizing uraemic tox- icity load in the large majority of the dialysis population. filtration (HDF) or more frequent/longer dialysis, was only partially associated with better results. Moreover, in the ma- jority of the positive studies, alternative interpretations of the results is possible, including a contribution of better volume control achievable with these particular dialysis techniques. Some 'observational' studies (2-7) showed a beneficial effect of high-flux versus low-flux synthetic dialysis mem- branes on survival, whereas prospective random controlled trials (RCTs) were inconclusive. In the Haemodialysis (HEMO) study, the largest random- ized clinical trial conducted in haemodialysis (HD) so far, patients were randomized to either a high-dialysis dose (achieved eKt/V ¼ 1.53 � 0.09, sp Kt/V ¼ 1.71 � 0.11) or a standard-dose goal (achieved eKt/V ¼ 1.16 � 0.08, sp Kt/V ¼ 1.32 � 0.09) and to dialysis with either high-flux dialysers (b2-microglobulin clearance of > 20 mL/min) or to low-flux dialysers—(b2-microglobulin clearance < 10 mL/ min). The results showed that a higher HD dose was not associated with a lower mortality risk compared with con- ventional HD dose (8). Thus, while a minimumKt/V ,a ccord- ing to the guidelines, is mandatory, the HEMO study clearly demonstrated that there are no advantages in further increas- ing the urea Kt/V, even in the high-flux membrane group. At the same time, each 10 mg/L increase in b2-M level was associated with an 11% increase in mortality, even after ad- justment for years on dialysis and residual kidney function. These results deserve further specifically designed studies in order to clarify if it is a matter of larger molecule removal or better fluid removal. In the other large trial in the field, the Membrane Perme- ability Outcome study, there was no significant difference in survival between high- and low-flux groups when all patients were included in the analysis (9). However, patients with serum albumin � 40 g/L on enrolment and with diabetes had a significantly better survival in the high-flux arm. High-flux dialysis was associated with a significantly lower accumulation of b2-microglobulin. Again, it is important to clarify if the better outcome was related to larger molecule removal or better fluid removal. Compared with conventional HD, HDF could theoretically offer some advantages: better clearance of middle- and