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Hemodiafiltration (HDF) is a renal replacement therapy that utilizes both diffusive clearance and convective transport to achieve greater clearance of middle-molecular-weight solutes. Among other factors, important prerequisites for the implementation of HDF include access to high-flux dialyzers, achievement of high blood flow rates, and availability of high volumes of sterile substitution/replacement fluids. Online hemodiafiltration (OL-HDF) is an established kidney replacement therapy, frequently used in many countries. Although in the United States, some prerequisites (e.g., access to high-flux dialyzers and achievement of high blood flow rates) for OL-HDF treatment are readily available; however, a machine capable of generating the online solution for OL-HDF is currently not available. As the clinical experience with HDF accumulates globally, it is worth examining the evidence for this kidney replacement therapy as used in routine clinical care. Such real-world evidence is increasingly recognized as valuable by clinicians and may inform regulatory decisions. In this review, we will focus on emerging global real-world data derived from routine clinical practices and examine how these data may complement those derived from clinical trials.

BackgroundHemodialysis patients have high-risk of severe SARS-CoV-2 infection but were unrepresented in randomized controlled trials evaluating the safety and efficacy of COVID-19 vaccines. We estimated the real-world effectiveness of COVID-19 vaccines in a large international cohort of hemodialysis patients.MethodsIn this historical, 1:1 matched cohort study, we included adult hemodialysis patients receiving treatment from December 1, 2020, to May 31, 2021. For each vaccinated patient, an unvaccinated control was selected among patients registered in the same country and attending a dialysis session around the first vaccination date. Matching was based on demographics, clinical characteristics, past COVID-19 infections and a risk score representing the local background risk of infection at vaccination dates. We estimated the effectiveness of mRNA and viral-carrier COVID-19 vaccines in preventing infection and mortality rates from a time-dependent Cox regression stratified by country.ResultsIn the effectiveness analysis concerning mRNA vaccines, we observed 850 SARS-CoV-2 infections and 201 COVID-19 related deaths among the 28110 patients during a mean follow up of 44 ± 40 days. In the effectiveness analysis concerning viral-carrier vaccines, we observed 297 SARS-CoV-2 infections and 64 COVID-19 related deaths among 12888 patients during a mean follow up of 48 ± 32 days. We observed 18.5/100-patient-year and 8.5/100-patient-year fewer infections and 5.4/100-patient-year and 5.2/100-patient-year fewer COVID-19 related deaths among patients vaccinated with mRNA and viral-carrier vaccines respectively, compared to matched unvaccinated controls. Estimated vaccine effectiveness at days 15, 30, 60 and 90 after the first dose of a mRNA vaccine was: for infection, 41.3%, 54.5%, 72.6% and 83.5% and, for death, 33.1%, 55.4%, 80.1% and 91.2%. Estimated vaccine effectiveness after the first dose of a viral-carrier vaccine was: for infection, 38.3% without increasing over time and, for death, 56.6%, 75.3%, 92.0% and 97.4%.ConclusionIn this large, real-world cohort of hemodialyzed patients, mRNA and viral-carrier COVID-19 vaccines were associated with reduced COVID-19 related mortality. Additionally, we observed a strong reduction of SARS-CoV-2 infection in hemodialysis patients receiving mRNA vaccines.

IntroductionPatients with end-stage kidney disease face a higher risk of severe outcomes from SARS-CoV-2 infection. Moreover, it is not well known to what extent potentially modifiable risk factors contribute to mortality risk. In this historical cohort study, we investigated the incidence and risk factors for 30-day mortality among hemodialysis patients with SARS-CoV-2 infection treated in the European Fresenius Medical Care NephroCare network using conventional and machine learning techniques.MethodsWe included adult hemodialysis patients with the first documented SARS-CoV-2 infection between February 1, 2020, and March 31, 2021, registered in the clinical database. The index date for the analysis was the first SARS-CoV-2 suspicion date. Patients were followed for up to 30 days until April 30, 2021. Demographics, comorbidities, and various modifiable risk factors, expressed as continuous parameters and as key performance indicators (KPIs), were considered to tap multiple dimensions including hemodynamic control, nutritional state, and mineral metabolism in the 6 months before the index date. We used logistic regression (LR) and XGBoost models to assess risk factors for 30-day mortality.ResultsWe included 9,211 patients (age 65.4 ± 13.7 years, dialysis vintage 4.2 ± 3.7 years) eligible for the study. The 30-day mortality rate was 20.8%. In LR models, several potentially modifiable factors were associated with higher mortality: body mass index (BMI) 30–40 kg/m2 (OR: 1.28, CI: 1.10–1.50), single-pool Kt/V (OR off-target vs on-target: 1.19, CI: 1.02–1.38), overhydration (OR: 1.15, CI: 1.01–1.32), and both low (ConclusionBoth conventional and machine learning techniques showed that KPIs and modifiable risk factors in different dimensions ascertained 6 months before the COVID-19 suspicion date were associated with 30-day COVID-19-related mortality. Our results suggest that adequate dialysis and achieving KPI targets remain of major importance during the COVID-19 pandemic as well.

BACKGROUND AND AIMS Patients with end-stage kidney disease (ESKD) face higher risk for severe outcomes from COVID-19 infection. Moreover, it is not well known to which extent potentially modifiable risk factors contribute to mortality risk. In this study, we investigated the incidence and risk factors for 30-day case-fatality of COVID-19 in haemodialysis patients treated in the European Fresenius Medical Care (FMC) Nephrocare network. METHOD In this historical cohort study, we included unvaccinated adult dialysis patients with a first documented SARS-CoV-2 infection between 1 February 2020 and 31 March 2021 (study period) registered in the European Clinical Database (EuCliD®). The first SARS-CoV-2 suspicion date for all documented infections was considered the index date for the analysis. Patients were followed for up to 30 days. Follow-up time was defined from the index date until the date of death, end of follow-up period or lost to follow-up, whichever occurred first. We ascertained patients’ characteristics in the 6-month period prior to index date. We used logistic regression and XGBoost to assess risk factors for 30-day mortality. RESULTS We included 9211 patients meeting the inclusion criteria for the study (Table 1). Age was 65.4 ± 13.7 years, dialysis vintage was 4.2 ± 3.7 years. In the follow up period, 1912 patients died within 30 days (20.8%, 95% confidence interval: 19.9%–21.6%). Correlates of COVID-19 related mortality are summarized in Table 2. Several potentially modifiable factors were associated with increased risk of death: patients on HD compared with online haemodiafiltration had shorter survival after presentation with COVID-19 as well as those who did not achieve the therapeutic targets for serum albumin, erythropoietin resistance index, protein catabolic rate, haemodynamic status, C-reactive protein, single-pool Kt/V, hydration status and serum sodium in the months before infection. The discrimination accuracy of prediction models developed with XGBoost was similar to that observed for main-effect logistic regression (AUC 0.69 and 0.71, respectively) suggesting that no major cross-interaction and non-linear effect could improve prediction accuracy. CONCLUSION We observed high 30-day COVID-19 related mortality among unvaccinated dialysis patients. Older patients, men and those with greater comorbidities had higher risk of death after COVID-19 infection. Derangement in potentially modifiable factors in the 6 months prior to COVID-19 infection was independently associated with increased mortality. Whether achievement of clinical therapeutic targets is associated with improved survival after COVID-19 infection is a matter of further research.

BACKGROUND AND AIMS To date, no large-scale study has evaluated the effectiveness of COVID-19 vaccines in hemodialysis patients. We sought to evaluate the effectiveness of vaccines against SARS-CoV-2 infections and death in haemodialysis patients registered in the Fresenius Medical Care (FMC) Nephrocare network. METHOD In this historical, 1:1 matched cohort study, we analysed electronic health records (EHR) of individuals receiving in-center haemodialysis therapy in FMC European dialysis clinics from 1 December 2020, to 31 May 2021 (study period). For each vaccinated patient, an unvaccinated patient was selected among patients registered in the same country and attending a dialysis session within +/–3 days from the vaccination date. Matching without replacement was based on demographics, clinical characteristics, past COVID-19 infections and a risk score representing the local (dialysis centre) background risk of infection at each vaccination date. The infection risk score was calculated from an artificial Intelligence model predicting the risk of COVID-19 outbreak in each clinic over a 2-week prediction horizon. The infection risk score was based on trends in regional COVID-19 epidemic metrics, FMC COVID-19 reporting system and clinical practice patterns. The index date was the date of the first vaccination for the vaccinated and the matching treatment date for the unvaccinated controls. To overcome violation of the proportional hazard assumption, we estimated the effectiveness of the COVID-19 vaccines in preventing infection and mortality rates as 1—hazard ratio estimated from a time-dependent extended Cox regression stratified by country and vaccine type. RESULTS We included 44 458 patients, 22 229 vaccinated and matched 22 229 unvaccinated. Distribution of covariates was balanced across study arms after matching (Figure 1A). In the effectiveness analysis on mRNA vaccines, we observed 850 SARS-CoV-2 infections and 201 COVID19-related deaths among the 28 110 patients (14 055 vaccinated and 14 055 unvaccinated) during a mean follow up time of 44 ± 40 days. In the effectiveness analysis of viral-vector vaccines, we observed 297 SARS-CoV-2 infections and 64 COVID19-related deaths among 12 888 patients (6444 vaccinated and 6444 unvaccinated) during a mean a follow-up time of 48 ± 32 days (Figure 1B). We observed 18.5/100 patient-year and 8.5/100 patient-year fewer infections and 5.4/100 patient-year and 5.2/100 patient-year fewer COVID-19-related deaths among patients vaccinated with mRNA and viral-vector vaccines respectively, as compared to matched unvaccinated controls. The effectiveness of COVID-19 vaccines concerning both symptomatic infections and COVID-related death along the follow up period is shown in Figure 2. CONCLUSION In this matched, historical cohort study, we observed a strong reduction in both SARS-CoV-2 symptomatic infection and COVID-19-related death among dialysis patients receiving an mRNA vaccine. Despite seemingly less protective against symptomatic infections, we observed similar reduction in COVID-19 mortality rate among patients receiving a viral-carrier vaccine.

Background It has been a long-standing clinical concern that haemodialysis (HD) patients on afternoon shifts (ASs) are more prone to protein-energy wasting (PEW) than those on morning shifts (MSs), as their dialysis scheme and post-dialysis symptoms may interfere with meal intake. We evaluated the effect of time of day of HD on the evolution of body composition changes and PEW surrogates. Methods We conducted a retrospective study among 9.963 incident HD patients treated in NephroCare centres (2011–16); data were routinely collected in the European Clinical Database. The course of multi-frequency bioimpedance determined lean and fat tissue indices (LTI and FTI) between patients in MSs/ASs over 2 years were compared with linear mixed models. Secondary PEW indicators were body mass index, albumin, creatinine index and normalized protein catabolic rate. Models included fixed (age, sex, vascular access and diabetes mellitus) and random effects (country and patient). Results Mean baseline LTI and FTI were comparable between MSs (LTI: 12.5 ± 2.9 kg/m2 and FTI: 13.7 ± 6.0 kg/m2) and ASs (LTI: 12.4 ± 2.9 kg/m2 and FTI: 13.2 ± 6.1 kg/m2). During follow-up, LTI decreased and FTI increased similarly, with a mean absolute change (baseline to 24 months) of −0.3 kg/m2 for LTI and +1.0 kg/m2 for FTI. The course of these malnutrition indicators did not differ between dialysis shifts (P for interaction ≥0.10). We also did not observe differences between groups for secondary PEW indicators. Conclusions This study suggests that a dialysis shift in the morning or in the afternoon does not impact the long-term nutritional status of HD patients. Regardless of time of day of HD, patients progressively lose muscle mass and increase body fat.

Introduction The clinical impact of COVID‐19 has not been established in the dialysis population. We evaluated the trajectories of clinical and laboratory parameters in hemodialysis (HD) patients. Methods We used data from adult HD patients treated at an integrated kidney disease company who received a reverse transcription polymerase chain reaction (RT‐PCR) test to investigate suspicion of a severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection between May 1 and September 1, 2020. Nonparametric smoothing splines were used to fit data for individual trajectories and estimate the mean change over time in patients testing positive or negative for SARS‐CoV‐2 and those who survived or died within 30 days of first suspicion or positive test date. For each clinical parameter of interest, the difference in average daily changes between COVID‐19 positive versus negative group and COVID‐19 survivor versus nonsurvivor group was estimated by fitting a linear mixed effects model based on measurements in the 14 days before (i.e., Day −14 to Day 0) Day 0. Results There were 12,836 HD patients with a suspicion of COVID‐19 who received RT‐PCR testing (8895 SARS‐CoV‐2 positive). We observed significantly different trends (p

Background Innovative care models such as public-private partnerships (PPPs) may help meet the challenge of providing cost-effective high-quality care for the steadily growing and complex chronic kidney disease population since they combine the expertise and efficiency of a specialized dialysis provider with the population care approach of a public entity. We report the five-years main clinical outcomes of a population of patients treated on hemodialysis within a PPP-care model in Italy. Methods This descriptive retrospective cohort study consisted of all consecutive hemodialysis patients treated in the NephroCare-operated Nephrology and Dialysis unit of the Seriate Hospital in 2012–2016, which exercises a PPP-care model. Clinical and treatment information was obtained from the European Clinical Database. Hospitalization outcomes and cumulative all-cause mortality incidences that accounted for competing risks were calculated. Results We included 401 hemodialysis patients (197 prevalent and 204 incident patients) in our study. The mean cohort age and age-adjusted Charlson Comorbidity Index were 67.0 years and 6.7, respectively. Patients were treated with online high-volume hemodiafiltration or high-flux hemodialysis. Parameters of treatment efficiency were above the recommended targets throughout the study period. Patients in the PPP experienced benefits in terms of hospitalization (average number of hospital admissions/patient-year: 0.79 and 1.13 for prevalent and incident patients, respectively; average length of hospitalization: 8.9 days for both groups) and had low cumulative all-cause mortality rates (12 months: 10.6 and 7.8%, 5 years: 42.0 and 35.9%, for prevalent and incident patients, respectively). Conclusions Results of our descriptive study suggest that hemodialysis patients treated within a PPP-care model framework received care complying with recommended treatment targets and may benefit in terms of hospitalization and mortality outcomes. Electronic supplementary material The online version of this article (10.1186/s12882-019-1224-2) contains supplementary material, which is available to authorized users.

Author(s): Chaudhuri, Sheetal; Lasky, Rachel; Jiao, Yue; Larkin, John; Monaghan, Caitlin; Winter, Anke; Neri, Luca; Kotanko, Peter; Hymes, Jeffrey; Lee, Sangho; Wang, Yuedong; Kooman, Jeroen P; Maddux, Franklin; Usvyat, Len | Abstract: IntroductionThe clinical impact of COVID-19 has not been established in the dialysis population. We evaluated the trajectories of clinical and laboratory parameters in hemodialysis (HD) patients.MethodsWe used data from adult HD patients treated at an integrated kidney disease company who received a reverse transcription polymerase chain reaction (RT-PCR) test to investigate suspicion of a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection between May 1 and September 1, 2020. Nonparametric smoothing splines were used to fit data for individual trajectories and estimate the mean change over time in patients testing positive or negative for SARS-CoV-2 and those who survived or died within 30 days of first suspicion or positive test date. For each clinical parameter of interest, the difference in average daily changes between COVID-19 positive versus negative group and COVID-19 survivor versus nonsurvivor group was estimated by fitting a linear mixed effects model based on measurements in the 14 days before (i.e., Day -14 to Day 0) Day 0.ResultsThere were 12,836 HD patients with a suspicion of COVID-19 who received RT-PCR testing (8895 SARS-CoV-2 positive). We observed significantly different trends (p l 0.05) in pre-HD systolic blood pressure (SBP), pre-HD pulse rate, body temperature, ferritin, neutrophils, lymphocytes, albumin, and interdialytic weight gain (IDWG) between COVID-19 positive and negative patients. For COVID-19 positive group, we observed significantly different clinical trends (p l 0.05) in pre-HD pulse rate, lymphocytes, neutrophils, and albumin between survivors and nonsurvivors. We also observed that, in the group of survivors, most clinical parameters returned to pre-COVID-19 levels within 60-90 days.ConclusionWe observed unique temporal trends in various clinical and laboratory parameters among HD patients who tested positive versus negative for SARS-CoV-2 infection and those who survived the infection versus those who died. These trends can help to define the physiological disturbances that characterize the onset and course of COVID-19 in HD patients.

Background and Aims Vascular calcification as cause of vascular stiffness is a major contributor to the high cardiac burden among stage 5 chronic kidney disease dialysis (CKD5HD) patients. Early identification of patients with high calcification propensity is crucial for proper risk stratification and management of these patients. Recently, a novel in vitro test (T50-test) was developed which determines calcification propensity of human serum and predicts mortality among ND-CKD (non-dialysis chronic kidney disease) patients, kidney transplant recipients and CKD5HD patients suffering from secondary hyperparathyroidism. We now evaluated whether these results can be confirmed in an unselected cohort of CKD5HD patients and can be used in the future for improving care of these patients. Method This prospective clinical study included 776 incident and prevalent hemodialysis patients from 8 Fresenius Medical Care NephroCare centers in Cataluña (Spain). T50 was determined at Calciscon AG, all other clinical data were retrieved from the European Clinical Database (EuCliD®). After their baseline T50 measurement, patients were followed for two years for the occurrence of the primary endpoint all-cause mortality. The association between T50 and all-cause mortality was examined by using proportional subdistribution hazards regression modelling accounting for kidney transplantation as competing event. In sensitivity analyses we adjusted for age, sex, vascular access (fistula/graft, catheter), treatment modality (HD, HDF), Charlson comorbidity index and dialysis vintage. Results Mean age of the study population was 72.2 years and 63.8% were male. 42.5% had diabetes and 55.0% past history of cardiovascular disease. Mean T50 was 283.4 min among the total cohort. During follow-up, 185 (23.8%) patients died. Patients who reached the endpoint had a significantly lower T50 at baseline as compared to those who survived during follow-up (269.6 vs 287.7 min, p = 0.001). A cross-validated model (mean c statistic: 0.5767) identified T50 as a linear predictor of all-cause-mortality (subdistribution hazard ratio (per min): 0.9957, 95% CI [0.9933;0.9981]). T50 remained a significant predictor of all-cause mortality after adjusting for relevant confounding in sensitivity analyses. Conclusion In this prospective study, we confirmed that T50 is an independent predictor of all-cause mortality among a large unselected cohort of hemodialysis patients. T50 may be used to identify patients with high vascular calcification propensity and mortality risks and may help physicians to implement a personalized and more precise renal replacement therapy option.

Background and Aims Chronic kidney diseases disrupt normal bone-mineral axis endocrine functions causing the onset of mineral bone disorders (MBDs). The general and hemodialysis (HD) populations have been found to exhibit diurnal rhythms in phosphate (PO4), calcium (Ca), and parathyroid hormone (PTH) regulation (Trivedi et al. J Nephrol. 2015), but reference values for fluctuations have not been established in HD patients and do not consider PO4 binder use. We profiled the diurnal rhythms of MBD labs overall and stratified by PO4 binder use in a large nationally representative HD population in the United States. Method We used prevalent in-center HD patient (vintage >90 days) data on adults (age ≥18 years) treated at a dialysis organization in 2018. Mean annual pre-HD blood PO4, corrected Ca, and intact PTH levels were computed in 2-hour periods through 24 hours for the population and stratified by binder use. HD initiation time was a varying exposure, allowing patients to switch time groups if blood draws occurred in multiple time periods. Mean MBD lab levels with 95% confidence limits were plotted using nonparametric smoothing spline models to fit data and calculate trajectories throughout the day. Results The population of adult HD patients (n=156,873) was: mean age 62.8±14.3 years, 57.1% male, 58.2% white race, 41.9% with diabetes, 19.6% with congestive heart failure, and HD vintage 1510±1289 days. Mean pre-dialysis albumin=3.8±0.4 g/dL, PO4=5.4±1.5 mg/dL, corrected Ca=9.1±0.6 mg/dL, PTH=468±333 pg/dL for the population. Mean PO4, corrected Ca and PTH levels varied remarkably by 0.9 mg/dL, 0.2 mg/dL, and 186 pg/dL throughout the day. For PO4 and PTH, nadir levels occurred from 0900 to 1100 hours (5.3±1.6 mg/dL and 473±340 pg/dL), followed by a rise to a mid-day peak from 1700 to 1900 hours (5.8±1.8 mg/dL and 562±401 pg/dL), and the highest levels had a peak time from 2300 to 0100 hours (6.2±2.1 mg/dL and 659±389 pg/dL) (Figure 1A & C). Corrected Ca showed relatively inverse fluctuations to PO4 and PTH, with peak levels from 1100 to 1300 hours (9.2±0.7 mg/dL) and nadir levels from 1900 to 2100 hours (9.0±0.7 mg/dL) (Figure 1B). Similar fluctuations and levels were observed for PO4 and PTH among patients using any phosphate binder type (90.7%), however, patients not using a phosphate binder exhibited absolute values that were persistently lower at every timepoint (Figure 1D & F). Corrected Ca levels were similar by any binder use (Figure 1E). Conclusion Our results suggest PO4, Ca, and PTH levels have a diurnal variation of 0.9 mg/dL, 0.2 mg/dL, and 186 pg/dL in hemodialysis patients. PO4 and PTH exhibit a nadir in the morning, a mid-day peak and a larger nocturnal peak. Ca exhibits relatively inverse diurnal fluctuations with PO4 and PTH. Patients using any binder exhibit similar fluctuations and levels of PO4 and PTH; while patients not requiring a binder have similar fluctuations, yet persistently lower levels of PO4 and PTH. Given PO4 binder and calcimimetic therapies are commonly used for treatment of MBDs based on pre-dialysis blood levels, these findings provide insights for further research and pose the question if algorithms are warranted to compute daily time-adjusted levels for MBD laboratories.

Background and Aims The patient’s reported perception of their health-related quality of life (HRQOL) are important patient-centered metrics that associate with outcomes in hemodialysis (HD) populations. Patients using an arteriovenous (AV) access (fistula or graft) tend to report better HRQOL compared with those dialyzing via a catheter (Wasse et al. 2007; Moura et al. 2014). However, these differences might be due to distinct characteristics of patients who have an AV access placed, or not. For example, catheter-dependent patients are typically older and have more comorbidities than those with an AV access. We considered a different way to evaluate the impact of vascular access on HRQOL in HD patients by assessing whether a change from a catheter to an AV access, and vice versa, associates with changes in HRQOL. Method We used data from adult in-center HD patients (age ≥18 years) treated at a large dialysis organization in the United States from 2016-2017. Patients who had one vascular access conversion and used the corresponding access for at least 12 months before and after the conversion were included in the analysis. HRQOL was assessed by Kidney Disease Quality of Life (KDQOL-36) surveys (0-100 scale) performed over the 12 months preceding and following the change. We computed the mean score for each of the five KDQOL domains in each time period and compared the score differences between pre- and post-access change using Student’s t-tests for each conversion type. Results A total of 1088 HD patients (mean age 59.2 years, 52.6% male, and 59.3% white race) switched from a catheter to an AV access and 3427 patients (mean age 61.8 years, 47.8% male, and 50.7% white race) switched from an AV access to a catheter over the analysis period. After conversion from a catheter to an AV access, patients reported significantly higher physical component summary (+0.5, p Conclusion Our results suggest switching from a catheter to an AV access may associate with patients perceiving an improved physical and mental HRQOL. In contrast, changing from an AV access to a catheter might associate with a diminished perception of physical HRQOL. Albeit distinctions in HRQOL are statistically significant, absolute differences were below two points and the clinical meaning needs to be assessed in further adjusted analyses considering the underlying reasons for vascular access conversions. Nonetheless, these findings may be of importance to provide more patient focused care.

Introduction Although high serum uric acid (SUA) has been consistently associated with an increased risk of death in the general population and in persons with nondialysis chronic kidney disease (CKD), studies in patients undergoing dialysis are conflicting. It has been postulated that low SUA simply reflects poor nutritional status in dialysis patients. We here characterize the association between SUA and the risk of death in a large dialysis cohort and explore effect modification by underlying nutritional status as reflected by body composition. Methods In this retrospective cohort study, we included 16,057 hemodialysis (HD) patients treated during 2007 to 2016 in NephroCare centers as recorded in the European Clinical Database (EuCliD). The association between SUA, all-cause, and cardiovascular (CV)−related mortality was evaluated with competing risk models and characterized with splines. Effect modification was explored by lean tissue index (LTI) and fat tissue index (FTI). Results During a mean of 1.8 years of follow-up, 2791 patients (17.4%) died. We found a multivariable-adjusted U-shaped pattern between SUA and all-cause mortality. Patients with SUA levels of 6.5 mg/dl (387 μmol/l) were at the lowest risk of death (subdistribution hazard ratio = 0.94 [confidence interval {CI} 0.91; 0.96]). The form of association was not meaningfully affected by underlying LTI and FTI. Conclusion We found a U-shaped pattern between SUA levels and all-cause mortality among HD patients, which was independent of the patients’ body composition., Graphical abstract

BackgroundAnemia is a major comorbidity of patients with end-stage renal disease and poses an enormous economic burden to health-care systems. High dose erythropoiesis-stimulating agents (ESAs) have been associated with unfavorable clinical outcomes. We explored whether mixed-dilution hemodiafiltration (Mixed-HDF), based on its innovative substitution modality, may improve anemia outcomes compared to the traditional post-dilution hemodiafiltration (Post-HDF).MethodsWe included 174 adult prevalent dialysis patients (87 on Mixed-HDF, 87 on Post-HDF) treated in 24 NephroCare dialysis centers between January 2010 and August 2016 into this retrospective cohort study. All patients were dialyzed three times per week and had fistula/graft as vascular access. Patients were matched at baseline and followed over a one-year period. The courses of hemoglobin levels (Hb) and monthly ESA consumption were compared between the two groups with linear mixed models.ResultsMean baseline Hb was 11.9±1.3 and 11.8±1.1g/dl in patients on Mixed- and Post-HDF, respectively. While Hb remained stable in patients on Mixed-HDF, it decreased slightly in patients on Post-HDF (at month 12: 11.8±1.2 vs 11.1±1.2g/dl). This tendency was confirmed by our linear mixed model (p = 0.0514 for treatment x time interaction). Baseline median ESA consumption was 6000 [Q1:0;Q3:16000] IU/4 weeks in both groups. Throughout the observation period ESA doses tended to be lower in the Mixed-HDF group (4000 [Q1:0;Q3:16000] vs 8000 [Q1:0;Q3:20000] IU/4 weeks at month 12; p = 0.0791 for treatment x time interaction). Sensitivity analyses, adjusting for differences not covered by matching at baseline, strengthened our results (Hb: p = 0.0124; ESA: p = 0.0687).ConclusionsResults of our explorative study suggest that patients on Mixed-HDF may have clinical benefits in terms of anemia management. This may also have a beneficial economic impact. Future studies are needed to confirm our hypothesis-generating results and to provide additional evidence on the potential beneficial effects of Mixed-HDF.