Peritoneal Phosphate Clearance: Determinants and Association With Mortality.

BACKGROUND: Dialytic phosphate removal is a cornerstone of the management of hyperphosphatemia in peritoneal dialysis (PD) patients, but the influencing factors on peritoneal phosphate clearance (PPC) are incompletely understood. Our objective was to explore clinically relevant factors associated with PPC in patients with different PD modality and peritoneal transport status and the association of PPC with mortality. METHODS: This is a cross-sectional and prospective observational study. Four hundred eighty-five PD patients were enrolled and divided into 2 groups according to PPC. All-cause mortality was evaluated after followed-up for at least 3 months. RESULTS: High PPC group showed lower mortality compared with Low PPC group by Kaplan-Meier analysis and log-rank test. Both multivariate linear regression and multivariate logistic regression revealed that high transport status, total effluent dialysate volume per day, continuous ambulatory PD (CAPD), and protein in total effluent dialysate volume appeared to be positively correlated with PPC; body mass index (BMI) and the normalized protein equivalent of total nitrogen appearance (nPNA) were negatively correlated with PPC. Besides PD modality and membrane transport status, total effluent dialysate volume showed a strong relationship with PPC, but the correlation differed among PD modalities. CONCLUSIONS: Higher PPC was associated with lower all-cause mortality risk in PD patients. Higher PPC correlated with CAPD modality, fast transport status, higher effluent dialysate volume and protein content, and with lower BMI and nPNA.

Comparison of Unplanned/Urgent-Start Versus Conventional-Start Peritoneal Dialysis: A Systematic Review and Meta-Analysis.

The timing of peritoneal dialysis (PD) initiation, whether conventional-start (planned) or urgent-start (unplanned), may impact the outcomes of PD and the rate of associated complications in individuals with chronic kidney disease (CKD). The goal of this study was to evaluate the effects of unplanned/urgent-start PD versus conventional-start PD in this cohort of patients. Electronic search of MEDLINE (via PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Scopus databases was done from inception until July 2023 for studies reporting outcomes of unplanned/urgent-start and conventional-start PD in CKD patients. Outcomes of interest included mechanical complications, post-procedure infections, mortality, and transfer to hemodialysis. Heterogeneity, publication bias, and the influence of individual studies on the pooled odds ratio (OR) with 95% confidence interval (CI) were evaluated. Twenty-seven studies were finally included in the review. The overall risk of post-procedure infectious was comparable for both PD initiation methods (OR: 1.05; 95% CI: 0.83-1.34). Similarly, the risks for peritonitis and exit site infections did not differ significantly. However, urgent-start PD correlated with a significantly higher risk of overall mechanical complications (OR: 1.70; 95% CI: 1.23-2.34). Specifically, the risk for leaks was notably higher (OR: 2.47; 95% CI: 1.67-3.65) in the urgent-start group compared to the conventional-start PD group. Urgent-start PD correlated with significantly increased mortality rates (OR: 1.83; 95% CI: 1.39-2.41). There was no difference in the likelihood of technique survival and transfer to hemodialysis. Both urgent-start and conventional-start PD correlated with similar risks of overall infectious complications. Urgent-start PD resulted in significantly increased risks of mechanical complications and mortality. Our findings emphasize the need for meticulous planning and consideration when opting for PD initiation.

Racial Disparities in End-Stage Kidney Disease Outcomes among Asians and Native Hawaiians and Other Pacific Islanders across Geographic Residence.

INTRODUCTION: While Asian and Native Hawaiian and other Pacific Islander (NHOPI) patients have a high prevalence of kidney disease risk factors, there are sparse data examining their end-stage kidney disease (ESKD) outcomes. As Hawaii has high representation of Asian and NHOPI individuals, we compared their ESKD outcomes based on residence in the mainland USA versus Hawaii/Pacific Islands (PIs). MATERIALS AND METHODS: Using United States Renal Data System data, we examined the impact of geographic residence in the mainland versus Hawaii/PIs on race-mortality associations among incident ESKD patients transitioning to dialysis over January 1, 2000-December 31, 2016 using Cox regression. We examined likelihood of post-dialysis kidney transplantation using Cox models and cumulative incidence curves. RESULTS: Compared with White patients in the mainland, Asian and NHOPI patients in the mainland had lower mortality: adjusted HRs (95% CIs) 0.67 (0.66-0.67) and 0.72 (0.70-0.73), respectively. When examining Asian and NHOPI patients in Hawaii/PIs, survival benefit was attenuated in Asian and diminished to the null in NHOPI patients (ref: mainland White patients). Cumulative incidence curves comparing Asian, NHOPI, and White patients showed Asian and NHOPI patients in the mainland had the highest likelihood of transplantation, whereas NHOPI and Asian patients in Hawaii/PIs had the lowest likelihood. CONCLUSION: In the mainland, Asian and NHOPI patients had lower mortality versus White patients, whereas in Hawaii/PIs, this survival benefit was diminished in Asian and mitigated in NHOPI patients. NHOPI and Asian patients in Hawaii/PIs had less transplantation versus those in the mainland. Further research is needed to uncover factors contributing to differential ESKD outcomes among Asian and NHOPI patients across geographic residence.

Incidence of major cardiovascular events at 1, 2, and 5 years and mortality in incident patients on peritoneal dialysis regarding their nutritional status by bioimpedanciometry: A multicenter study in Colombia.

BACKGROUND: The nutritional status of incident patients on peritoneal dialysis (PD) has been associated with survival outcomes. Bioimpedanciometry (BCM) enables to establish a nutritional diagnosis, the volume status, and correlates these findings with survival. METHODS: This study used a retrospective multicenter historical cohort. RESULTS: In this study, which included 420 incident patients on peritoneal dialysis with a 5-year follow-up, a cumulative incidence of major adverse cardiovascular events (MACE) of 28.8% was found, being higher in the diabetic population at 36.8%. In regard to the nutritional status in this population, it was found that approximately 44% had altered nutritional status; 34% were found to be in sarcopenia; 6.7% sarcopenic obesity; and 2.8% in obesity (p < 0.001). In the survival analysis, a lower probability of survival was found in patients with overhydration (OH) greater than 3 L (p < 0.001) and in patients with altered nutritional status due to sarcopenia, sarcopenic obesity, and obesity (p 0.016). According to survival in the subgroup of the diabetic population, a lower probability of survival was found in this group of patients (p: 0.011). The overall mortality of the study population was 18%, being higher in the first 2 years, with the most important causes of mortality being cardiovascular. Of the deceased population, 51% were diabetic patients (p: 0.012). CONCLUSION: In incident patients on peritoneal dialysis, sarcopenic obesity, sarcopenia, overhydration status determined by BCM, and having a diagnosis of diabetes are related to a lower probability of survival; MACE outcomes are more frequent in the diabetic population.

Influence of renin-angiotensin system blockades on vascular access survival in patients on maintenance hemodialysis.

INTRODUCTION: Results on the association between the use of renin-angiotensin system blockades (RASBs) and vascular access-related outcomes are inconsistent. We aimed to compare vascular access-related outcomes according to the use of RASBs in hemodialysis patients. METHODS: This study used data from a national hemodialysis quality assessment program of the Republic of Korea (n = 54,903). Group 1 was not prescribed any blood pressure-lowering drugs (n = 28,521). Group 2 was prescribed other blood pressure-lowering agents except for RASBs (n = 9571). Group 3 was prescribed RASBs (n = 16,811). Vascular access-related outcomes were classified into intervention-free survival (IFS), thrombosis-free survival (TFS), and vascular access survival (VAS). RESULTS: No significant difference in the three access survival rates was identified among the three groups. The multivariate Cox regression analyses indicated that Group 3 had better outcomes in IFS and TFS than Group 1. The numbers of angioplasties performed were significantly greater in Group 1 than in the other two groups. The numbers of thrombectomies performed were significantly the lowest in Group 3 among all the groups. CONCLUSIONS: Our study revealed different results according to types of access survival in univariate or multivariate analyses. The association of RASBs with favorable outcomes in vascular access remains unclear.

Years of life lost and long-term outcomes due to glomerular disease in a Southeast Asian Cohort.

Death and end-stage kidney disease (ESKD) are major outcomes of glomerular disease. (GD) The years of potential life lost (YLL) may provide additional insight into the disease burden beyond death rates. There is limited data on premature mortality in GD. In this retrospective observational cohort study, we evaluated the mortality, ESKD rates, and YLL in Thais with biopsy-proven GD. The mortality and combined outcome rates were determined by log-rank test and ESKD by using a competing risk model. YLL and premature life lost before age 60 were calculated for different GD based on the life expectancy of the Thai population. Patients with GD (n = 949) were followed for 5237 patient years. The death rate and ESKD rates (95%CI) were 4.2 (3.7-4.9) and 3.3 (2.9-3.9) per 100 patient-years, respectively. Paraprotein-related kidney disease had the highest death rate, and diabetic nephropathy had the highest ESKD rate. Despite not having the highest death rate, lupus nephritis (LN) had the highest YLL (41% of all GD) and premature loss of life before age 60. In conclusion, YLL provided a different disease burden assessment compared to mortality rates and identified LN as the major cause of premature death due to GD in a Southeast Asian cohort.

Effect of Hemodiafiltration or Hemodialysis on Mortality in Kidney Failure.

BACKGROUND: Several studies have suggested that patients with kidney failure may benefit from high-dose hemodiafiltration as compared with standard hemodialysis. However, given the limitations of the various published studies, additional data are needed. METHODS: We conducted a pragmatic, multinational, randomized, controlled trial involving patients with kidney failure who had received high-flux hemodialysis for at least 3 months. All the patients were deemed to be candidates for a convection volume of at least 23 liters per session (as required for high-dose hemodiafiltration) and were able to complete patient-reported outcome assessments. The patients were assigned to receive high-dose hemodiafiltration or continuation of conventional high-flux hemodialysis. The primary outcome was death from any cause. Key secondary outcomes were cause-specific death, a composite of fatal or nonfatal cardiovascular events, kidney transplantation, and recurrent all-cause or infection-related hospitalizations. RESULTS: A total of 1360 patients underwent randomization: 683 to receive high-dose hemodiafiltration and 677 to receive high-flux hemodialysis. The median follow-up was 30 months (interquartile range, 27 to 38). The mean convection volume during the trial in the hemodiafiltration group was 25.3 liters per session. Death from any cause occurred in 118 patients (17.3%) in the hemodiafiltration group and in 148 patients (21.9%) in the hemodialysis group (hazard ratio, 0.77; 95% confidence interval, 0.65 to 0.93). CONCLUSIONS: In patients with kidney failure resulting in kidney-replacement therapy, the use of high-dose hemodiafiltration resulted in a lower risk of death from any cause than conventional high-flux hemodialysis. (Funded by the European Commission Research and Innovation; CONVINCE Dutch Trial Register number, NTR7138.).

High facility-level serum potassium variability associated with mortality in hemodialysis patients: results from Chinese Dialysis Outcomes and Practice Patterns Study (DOPPS).

The role of facility-level serum potassium (sK+) variability (FL-SPV) in dialysis patients has not been extensively studied. This study aimed to evaluate the association between FL-SPV and clinical outcomes in hemodialysis patients using data from the China Dialysis Outcomes and Practice Patterns Study (DOPPS) 5. FL-SPV was defined as the standard deviation (SD) of baseline sK+ of all patients in each dialysis center. The mean and SD values of FL-SPV of all participants were calculated, and patients were divided into the high FL-SPV (>the mean value) and low FL-SPV (≤the mean value) groups. Totally, 1339 patients were included, with a mean FL-SPV of 0.800 mmol/L. Twenty-three centers with 656 patients were in the low FL-SPV group, and 22 centers with 683 patients were in the high FL-SPV group. Multivariate logistic regression analysis showed that liver cirrhosis (OR = 4.682, 95% CI: 1.246-17.593), baseline sK+ (<3.5 vs. 3.5 ≤ sK+ < 5.5 mmol/L, OR = 2.394, 95% CI: 1.095-5.234; ≥5.5 vs. 3.5 ≤ sK+ < 5.5 mmol/L, OR = 1.451, 95% CI: 1.087-1.939), dialysis <3 times/week (OR = 1.472, 95% CI: 1.073-2.020), facility patients' number (OR = 1.088, 95% CI: 1.058-1.119), serum HCO3- level (OR = 0.952, 95% CI: 0.921-0.984), dialysis vintage (OR = 0.919, 95% CI: 0.888-0.950), other cardiovascular disease (OR = 0.508, 95% CI: 0.369-0.700), and using high-flux dialyzer (OR = 0.425, 95% CI: 0.250-0.724) were independently associated with high FL-SPV (all p < .05). After adjusting potential confounders, high FL-SPV was an independent risk factor for all-cause death (HR = 1.420, 95% CI: 1.044-1.933) and cardiovascular death (HR = 1.827, 95% CI: 1.188-2.810). Enhancing the management of sK+ of hemodialysis patients and reducing FL-SPV may improve patient survival.

The effect of intradialytic exercise on dialysis patient survival: a randomized controlled trial.

BACKGROUND: Patients with kidney failure have a high mortality rate. This study aimed to evaluate the effect of intradialytic exercise on survival in patients receiving hemodialysis (HD). METHODS: In this randomized controlled trial conducted in a HD center in Iran, adult patients receiving chronic HD were randomized to intradialytic exercise (60 min) in the second hour of thrice weekly dialysis for 6 months (intervention) or no intradialytic exercise (control). The primary outcome was survival rate at 12 months. Secondary outcomes were serum albumin, hemoglobin, hematocrit, red blood cell count, serum calcium, serum phosphorous, parathyroid hormone, physical function (6-min walk test) and nutritional status (Geriatric Nutritional Risk Index) during the first 6 months. The trial follow-up period was 12 months. RESULTS: The study included 74 participants (44 males) with an age average of 64 ± 12 years old and a dialysis history of 27 ± 12 months, randomized to intervention (n = 37) or control (n = 37). Compared with controls, 1-year survival was higher in the intervention group (94% vs 73%, P = 0.01). The hazard ratio in univariate analysis in intervention group was 0.17 (95% CI 0.04-0.8; P = 0.02) compared to that in control group. During the 6-month intervention period, significant between-group changes were observed in all secondary outcomes between the intervention and control groups. CONCLUSION: Intradialytic exercise performed for at least 60 min during thrice weekly dialysis sessions improves survival in adult patients receiving HD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04898608. Retrospectively registered on 24/05/2021. Registered trial name: The Effect of Intradialytic Exercise on Dialysis Patients Survival.

Mediation of serum albumin in the association of serum potassium with mortality in Chinese dialysis patients: a prospective cohort study.

BACKGROUND: The clinical importance of hypokalemia is likely underrecognized in Chinese dialysis patients, and whether its clinical effect was mediated by serum albumin is not fully elucidated. This study aimed to explore the association between serum potassium and mortality in dialysis patients of a Chinese nationwide multicenter cohort, taking albumin as a consideration. METHODS: This was a prospective nation-wide multicenter cohort study. Restricted cubic splines were used to test the linearity of serum potassium and relationships with all-cause (AC) and cardiovascular (CV) mortality and a subsequent two-line piecewise linear model was fitted to approach the nadir. A mediation analysis was performed to examine relations of albumin to potassium and mortalities. RESULTS: A total of 10,027 patients were included, of whom 6605 were peritoneal dialysis and 3422 were hemodialysis patients. In the overall population, the mean age was 51.7 ±â€Š14.8 years, 55.3%(5546/10,027) were male, and the median dialysis vintage was 13.60 (4.70, 39.70) months. Baseline serum potassium was 4.30 ±â€Š0.88 mmol/L. After a median follow-up period of 26.87 (14.77, 41.50) months, a U-shape was found between potassium and mortality, and a marked increase in risk at lower potassium but a moderate elevation in risk at higher potassium were observed. The nadir for AC mortality risk was estimated from piecewise linear models to be a potassium concentration of 4.0 mmol/L. Interestingly, the significance of the association between potassium and mortality was attenuated when albumin was introduced into the extended adjusted model. A subsequent significant mediation by albumin for potassium and AC and CV mortalities were found ( P < 0.001 for both), indicating that hypokalemia led to higher mortality mediated by low serum albumin, which was a surrogate of poor nutritional status and inflammation. CONCLUSIONS: Associations between potassium and mortalities were U-shaped in the overall population. The nadir for AC mortality risk was at a potassium of 4.0 mmol/L. Serum albumin mediated the association between potassium and AC and CV mortalities.

Mediation of serum albumin in the association of serum potassium with mortality in Chinese dialysis patients: a prospective cohort study / 中华医学杂志(英文版)

BACKGROUND@#The clinical importance of hypokalemia is likely underrecognized in Chinese dialysis patients, and whether its clinical effect was mediated by serum albumin is not fully elucidated. This study aimed to explore the association between serum potassium and mortality in dialysis patients of a Chinese nationwide multicenter cohort, taking albumin as a consideration.@*METHODS@#This was a prospective nation-wide multicenter cohort study. Restricted cubic splines were used to test the linearity of serum potassium and relationships with all-cause (AC) and cardiovascular (CV) mortality and a subsequent two-line piecewise linear model was fitted to approach the nadir. A mediation analysis was performed to examine relations of albumin to potassium and mortalities.@*RESULTS@#A total of 10,027 patients were included, of whom 6605 were peritoneal dialysis and 3422 were hemodialysis patients. In the overall population, the mean age was 51.7 ± 14.8 years, 55.3%(5546/10,027) were male, and the median dialysis vintage was 13.60 (4.70, 39.70) months. Baseline serum potassium was 4.30 ± 0.88 mmol/L. After a median follow-up period of 26.87 (14.77, 41.50) months, a U-shape was found between potassium and mortality, and a marked increase in risk at lower potassium but a moderate elevation in risk at higher potassium were observed. The nadir for AC mortality risk was estimated from piecewise linear models to be a potassium concentration of 4.0 mmol/L. Interestingly, the significance of the association between potassium and mortality was attenuated when albumin was introduced into the extended adjusted model. A subsequent significant mediation by albumin for potassium and AC and CV mortalities were found ( P < 0.001 for both), indicating that hypokalemia led to higher mortality mediated by low serum albumin, which was a surrogate of poor nutritional status and inflammation.@*CONCLUSIONS@#Associations between potassium and mortalities were U-shaped in the overall population. The nadir for AC mortality risk was at a potassium of 4.0 mmol/L. Serum albumin mediated the association between potassium and AC and CV mortalities.

A Machine Learning Model for Predicting Mortality within 90 Days of Dialysis Initiation.

Background: The first 90 days after dialysis initiation are associated with high morbidity and mortality in end-stage kidney disease (ESKD) patients. A machine learning-based tool for predicting mortality could inform patient-clinician shared decision making on whether to initiate dialysis or pursue medical management. We used the eXtreme Gradient Boosting (XGBoost) algorithm to predict mortality in the first 90 days after dialysis initiation in a nationally representative population from the United States Renal Data System. Methods: A cohort of adults initiating dialysis between 2008-2017 were studied for outcome of death within 90 days of dialysis initiation. The study dataset included 188 candidate predictors prognostic of early mortality that were known on or before the first day of dialysis and was partitioned into training (70%) and testing (30%) subsets. XGBoost modeling used a complete-case set and a dataset obtained from multiple imputation. Model performance was evaluated by c-statistics overall and stratified by subgroups of age, sex, race, and dialysis modality. Results: The analysis included 1,150,195 patients with ESKD, of whom 86,083 (8%) died in the first 90 days after dialysis initiation. The XGBoost models discriminated mortality risk in the nonimputed (c=0.826, 95% CI, 0.823 to 0.828) and imputed (c=0.827, 95% CI, 0.823 to 0.827) models and performed well across nearly every subgroup (race, age, sex, and dialysis modality) evaluated (c>0.75). Across predicted risk thresholds of 10%-50%, higher risk thresholds showed declining sensitivity (0.69-0.04) with improving specificity (0.79-0.99); similarly, positive likelihood ratio was highest at the 40% threshold, whereas the negative likelihood ratio was lowest at the 10% threshold. After calibration using isotonic regression, the model accurately estimated the probability of mortality across all ranges of predicted risk. Conclusions: The XGBoost-based model developed in this study discriminated risk of early mortality after dialysis initiation with excellent calibration and performed well across key subgroups.

County-Level Characteristics Associated with Variation in ESKD Mortality in the United States, 2010-2018.

Background: Geographic and neighborhood-level factors, such as poverty and education, have been associated with an increased risk for incident ESKD, likelihood of receiving pre-ESKD care, and likelihood of receiving a transplant. However, few studies have examined whether these same factors are associated with ESKD mortality. In this study, we examined county-level variation in ESKD mortality and identified county-level characteristics associated with this variation. Methods: We identified 1,515,986 individuals (aged 18-84 years) initiating RRT (dialysis or transplant) between 2010 and 2018 using the United States Renal Data System. Among 2781 counties, we estimated county-level, all-cause, age-standardized mortality rates (ASMR) among patients with ESKD. We then identified county-level demographic (e.g., percent female), socioeconomic (e.g., percent unemployed), healthcare (e.g., percent without health insurance), and health behavior (e.g., percent current smokers) characteristics associated with ASMR using multivariable hierarchic linear mixed models and quantified the percentage of ASMR variation explained by county-level characteristics. Results: County-level ESKD ASMR ranged from 45 to 1022 per 1000 person-years (PY) (mean, 119 per 1000 PY). ASMRs were highest in counties located in the Tennessee Valley and Appalachia regions, and lowest in counties located in New England, the Pacific Northwest, and Southern California. In fully adjusted models, county-level characteristics significantly associated with higher ESKD mortality included a lower percentage of Black residents (-4.94 per 1000 PY), lower transplant rate (-4.08 per 1000 PY), and higher healthcare expenditures (5.21 per 1000 PY). Overall, county-level characteristics explained 19% of variation in ESKD mortality. Conclusions: Counties with high ESKD-related mortality may benefit from targeted and multilevel interventions that combine knowledge from a growing evidence base on the interplay between individual and community-level factors associated with ESKD mortality.