Association of residual urine output with mortality, quality of life, and inflammation in incident hemodialysis patients: the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) Study

Preservation of residual kidney function in hemodialysis patients: reviving an old concept

Residual kidney function (RKF) may confer a variety of benefits to patients on maintenance dialysis. RKF provides continuous clearance of middle molecules and protein-bound solutes. Whereas the definition of RKF varies across studies, interdialytic urine volume may emerge as a pragmatic alternative to more cumbersome calculations. RKF preservation is associated with better patient outcomes including survival and quality of life and is a clinical parameter and research focus in peritoneal dialysis. We propose the following practical considerations to preserve RKF, especially in newly transitioned (incident) hemodialysis patients: (1) periodic monitoring of RKF in hemodialysis patients through urine volume and including residual urea clearance with dialysis adequacy and outcome markers such as anemia, fluid gains, minerals and electrolytes, nutritional, status and quality of life; (2) avoidance of nephrotoxic agents such as radiocontrast dye, nonsteroidal anti-inflammatory drugs, and aminoglycosides; (3) more rigorous hypertension control and minimizing intradialytic hypotensive episodes; (4) individualizing the initial dialysis prescription with consideration of an incremental/infrequent approach to hemodialysis initiation (e.g., twice weekly) or peritoneal dialysis; and (5) considering a lower protein diet, especially on nondialysis days. Because RKF appears to be associated with better patient outcomes, it requires more clinical and research focus in the care of hemodialysis and peritoneal dialysis patients.

Incremental Hemodialysis, Residual Kidney Function, and Mortality Risk in Incident Dialysis Patients: A Cohort Study

BACKGROUND

Maintenance hemodialysis is typically prescribed thrice weekly irrespective of a patient's residual kidney function (RKF). We hypothesized that a less frequent schedule at hemodialysis therapy initiation is associated with greater preservation of RKF without compromising survival among patients with substantial RKF.

STUDY DESIGN

A longitudinal cohort.

SETTING & PARTICIPANTS

23,645 patients who initiated maintenance hemodialysis therapy in a large dialysis organization in the United States (January 2007 to December 2010), had available RKF data during the first 91 days (or quarter) of dialysis, and survived the first year.

PREDICTOR

Incremental (routine twice weekly for >6 continuous weeks during the first 91 days upon transition to dialysis) versus conventional (thrice weekly) hemodialysis regimens during the same time.

OUTCOMES

Changes in renal urea clearance and urine volume during 1 year after the first quarter and survival after the first year.

RESULTS

Among 23,645 included patients, 51% had substantial renal urea clearance (≥3.0mL/min/1.73m(2)) at baseline. Compared with 8,068 patients with conventional hemodialysis regimens matched based on baseline renal urea clearance, urine volume, age, sex, diabetes, and central venous catheter use, 351 patients with incremental regimens exhibited 16% (95% CI, 5%-28%) and 15% (95% CI, 2%-30%) more preserved renal urea clearance and urine volume at the second quarter, respectively, which persisted across the following quarters. Incremental regimens showed higher mortality risk in patients with inadequate baseline renal urea clearance (≤3.0mL/min/1.73m(2); HR, 1.61; 95% CI, 1.07-2.44), but not in those with higher baseline renal urea clearance (HR, 0.99; 95% CI, 0.76-1.28). Results were similar in a subgroup defined by baseline urine volume of 600mL/d.

LIMITATIONS

Potential selection bias and wide CIs.

CONCLUSIONS

Among incident hemodialysis patients with substantial RKF, incremental hemodialysis may be a safe treatment regimen and is associated with greater preservation of RKF, whereas higher mortality is observed after the first year of dialysis in those with the lowest RKF. Clinical trials are needed to examine the safety and effectiveness of twice-weekly hemodialysis.

Trimethylamine N-Oxide and Cardiovascular Events in Hemodialysis Patients

Cardiovascular disease causes over 50% of the deaths in dialysis patients, and the risk of death is higher in white than in black patients. The underlying mechanisms for these findings are unknown. We determined the association of the proatherogenic metabolite trimethylamine N-oxide (TMAO) with cardiovascular outcomes in hemodialysis patients and assessed whether this association differs by race. We measured TMAO in stored serum samples obtained 3-6 months after randomization from a total of 1232 white and black patients of the Hemodialysis Study, and analyzed the association of TMAO with cardiovascular outcomes using Cox models adjusted for potential confounders (demographics, clinical characteristics, comorbidities, albumin, and residual kidney function). Mean age of the patients was 58 years; 35% of patients were white. TMAO concentration did not differ between whites and blacks. In whites, 2-fold higher TMAO associated with higher risk (hazard ratio [95% confidence interval]) of cardiac death (1.45 [1.24 to 1.69]), sudden cardiac death [1.70 (1.34 to 2.15)], first cardiovascular event (1.15 [1.01 to 1.32]), and any-cause death (1.22 [1.09 to 1.36]). In blacks, the association was nonlinear and significant only for cardiac death among patients with TMAO concentrations below the median (1.58 [1.03 to 2.44]). Compared with blacks in the same quintile, whites in the highest quintile for TMAO (≥135 μM) had a 4-fold higher risk of cardiac or sudden cardiac death and a 2-fold higher risk of any-cause death. We conclude that TMAO concentration associates with cardiovascular events in hemodialysis patients but the effects differ by race.

Survival by Dialysis Modality-Who Cares?

In light of the recent emphasis on patient-centered outcomes and quality of life for patients with kidney disease, we contend that the nephrology community should no longer fund, perform, or publish studies that compare survival by dialysis modality. These studies have become redundant; they are methodologically limited, unhelpful in practice, and therefore a waste of resources. More than two decades of these publications show similar survival between patients undergoing peritoneal dialysis and those receiving thrice-weekly conventional hemodialysis, with differences only for specific subgroups. In clinical practice, modality choice should be individualized with the aim of maximizing quality of life, patient-reported outcomes, and achieving patient-centered goals. Expected survival is often irrelevant to modality choice. Even for the younger and fitter home hemodialysis population, quality of life, not just duration of survival, is a major priority. On the other hand, increasing evidence suggests that patients with ESRD continue to experience poor quality of life because of high symptom burden, unsolved clinical problems, and unmet needs. Patients care more about how they will live instead of how long. It is our responsibility to align our research with their needs. Only by doing so can we meet the challenges of ESRD patient care in the coming decades.

Residual Kidney Function Decline and Mortality in Incident Hemodialysis Patients

In patients with ESRD, residual kidney function (RKF) contributes to achievement of adequate solute clearance. However, few studies have examined RKF in patients on hemodialysis. In a longitudinal cohort of 6538 patients who started maintenance hemodialysis over a 4-year period (January 2007 through December 2010) and had available renal urea clearance (CL_urea) data at baseline and 1 year after hemodialysis initiation, we examined the association of annual change in renal CL_urea rate with subsequent survival. The median (interquartile range) baseline value and mean±SD annual change of CL_urea were 3.3 (1.9-5.0) and -1.1±2.8 ml/min per 1.73 m², respectively. Greater CL_urea rate 1 year after hemodialysis initiation associated with better survival. Furthermore, we found a gradient association between loss of RKF and all-cause mortality: changes in CL_urea rate of -6.0 and +3.0 ml/min per 1.73 m² per year associated with case mix-adjusted hazard ratios (95% confidence intervals) of 2.00 (1.55 to 2.59) and 0. 61 (0.50 to 0.74), respectively (reference: -1.5 ml/min per 1.73 m² per year). These associations remained robust against adjustment for laboratory variables and ultrafiltration rate and were consistent across strata of baseline CL_urea, age, sex, race, diabetes status, presence of congestive heart failure, and hemoglobin, serum albumin, and serum phosphorus levels. Sensitivity analyses using urine volume as another index of RKF yielded consistent associations. In conclusion, RKF decline during the first year of dialysis has a graded association with all-cause mortality among incident hemodialysis patients. The clinical benefits of RKF preservation strategies on mortality should be determined.

Diuretics, Limited Ultrafiltration, and Residual Renal Function in Incident Hemodialysis Patients: A Case Series

The effect of diuretics on residual renal function expressed as residual GFR (rGFR) and urine volume (rUV) using 24-hour urine collections has not been well examined in hemodialysis (HD) patients. We present a small (seven patient) but provocative case series describing a strikingly low rate of decline in rUV and rGFR (average of creatinine and urea clearances, 24-hour urine collections) in patients treated with increasing doses of furosemide (up to 360 mg/day) during the first 2 years after initiation of HD. Between 6 and 12 months, the mean rUV fell by 1 ml/month, whereas rGFR declined by 0.03 ml/min/1.73 m(2) /month. The mean rate of decline from 12 to 24 months for rUV (33 ml/month) and rGFR (0.02 ml/min/1.73 m(2) /month) were also low. While data are clearly limited and the observation retrospective, they are consistent with the better documented benefit of diuretics observed in end-stage renal disease patients treated with peritoneal dialysis.

Prediction of Mortality in Incident Hemodialysis Patients: A Validation and Comparison of CHADS2, CHA2DS2, and CCI Scores

Background

The CHADS2 and CHA2DS2 scores are usually applied for stroke prediction in atrial fibrillation patients, and the Charlson comorbidity index (CCI) is a commonly used scale for assessing morbidity. The role in assessing mortality with score system in hemodialysis is not clear and comparisons are lacking. We aimed at evaluating CHADS2, CHA2DS2, and CCI scores to predict mortality in incident hemodialysis patients.

Methods

Using data from the Nation Health Insurance system of Taiwan (NHIRD) from 1 January 2005 to 31 December 2009, individuals ≧20 y/o who began hemodialysis identified by procedure code and receiving dialysis for > 3 months were included for our study. Renal transplantation patients after dialysis or PD patients were excluded. We calculated the CHADS2, CHA2DS2, and CCI score according to the ICD-9 code and categorized the patients into three groups in each system: 0–1, 2–3, over 4. A total of 3046 incident hemodialysis patients enrolled from NHIRD were examined for an association between the separate scoring systems (CHADS2, CHA2DS2, and CCI score) and mortality.

Results

CHADS2 and CHA2DS2 scores revealed good predictive value for total mortality (CHADS2 AUC = 0.805; CHA2DS2 AUC = 0.790). However, the CCI score did not reveal a similarly satisfying result (AUC = 0.576).

Conclusions

Our results show that CHADS2 and CHA2DS2 scores can be applied for mortality prediction in incident hemodialysis patients.

Estimating residual kidney function in dialysis patients without urine collection

Residual kidney function contributes substantially to solute clearance in dialysis patients but cannot be assessed without urine collection. We used serum filtration markers to develop dialysis-specific equations to estimate urinary urea clearance without the need for urine collection. In our development cohort, we measured 24-hour urine clearances under close supervision in 44 patients and validated these equations in 826 patients from the Netherlands Cooperative Study on the Adequacy of Dialysis. For the development and validation cohorts, median urinary urea clearance was 2.6 and 2.4 ml/min, respectively. During the 24-hour visit in the development cohort, serum β-trace protein concentrations remained in steady state but concentrations of all other markers increased. In the validation cohort, bias (median measured minus estimated clearance) was low for all equations. Precision was significantly better for β-trace protein and β2-microglobulin equations and the accuracy was significantly greater for β-trace protein, β2-microglobulin, and cystatin C equations, compared with the urea plus creatinine equation. Area under the receiver operator characteristic curve for detecting measured urinary urea clearance by equation-estimated urinary urea clearance (both 2 ml/min or more) were 0.821, 0.850, and 0.796 for β-trace protein, β2-microglobulin, and cystatin C equations, respectively; significantly greater than the 0.663 for the urea plus creatinine equation. Thus, residual renal function can be estimated in dialysis patients without urine collections.

Are Diuretics Underutilized in Dialysis Patients?

While oral diuretics are commonly used in patients with chronic kidney disease for the management of volume and blood pressure, they are often discontinued upon initiation of dialysis. We suggest that diuretics are considerably underutilized in peritoneal dialysis and haemodialysis patients despite numerous potential benefits and few side effects. Moreover, when diuretics are used, optimal doses are not always prescribed. In peritoneal dialysis, the use of diuretics can improve volume status and minimize the need for higher glucose-containing solutions. In patients on haemodialysis, diuretics can help lessen interdialytic weight gain, resulting in decreased ultrafiltration rates and fewer episodes of intradialytic hypotension. This paper will review the mechanism of action of diuretics in patients with renal insufficiency, quantify the risk of side effects and elaborate on the potential advantages of diuretic use in peritoneal dialysis and hemodialysis patients with residual kidney function.

Association of NTproBNP and cTnI with outpatient sudden cardiac death in hemodialysis patients: the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) study

BACKGROUND

Sudden cardiac death (SCD) is the most common etiology of death in hemodialysis patients but not much is known about its risk factors. The goal of our study was to determine the association and risk prediction of SCD by serum N-terminal prohormone of brain natriuretic peptide (NTproBNP) troponin I (cTnI) in hemodialysis patients.

METHODS

We measured NTproBNP and cTnI in 503 hemodialysis patients of a national prospective cohort study. We determined their association with SCD using Cox regression, adjusting for demographics, co-morbidities, and clinical factors and risk prediction using C-statistic and Net Reclassification Improvement (NRI).

RESULTS

Patients' mean age was 58 years and 54 % were male. During follow-up (median 3.5 years), there were 75 outpatient SCD events. In unadjusted and fully-adjusted models, NTproBNP had a significant association with the risk of SCD. Analyzed as a continuous variable, the risk of SCD increased 27 % with each 2-fold increase in NTproBNP (HR, 1.27 per doubling; 95 % CI, 1.13-1.43; p < 0.001). In categorical models, the risk of SCD was 3-fold higher in the highest tertile of NTproBNP (>7,350 pg/mL) compared with the lowest tertile (<1,710 pg/mL; HR for the highest tertile, 3.03; 95 % CI, 1.56-5.89; p = 0.001). Higher cTnI showed a trend towards increased risk of SCD in fully adjusted models, but was not statistically significant (HR, 1.17 per doubling; 95 % CI, 0.98-1.40; p = 0.08). Sensitivity analyses using competing risk models showed similar results. Improvement in risk prediction by adding cardiac biomarkers to conventional risk factors was greater with NTproBNP (C-statistic for 3-year risk: 0.810; 95 % CI, 0.757 to 0.864; and continuous NRI: 0.270; 95 % CI, 0.046 to 0.495) than with cTnI.

CONCLUSIONS

NTproBNP is associated with the risk of SCD in hemodialysis patients. Further research is needed to determine if biomarkers measurement can guide SCD risk prevention strategies in dialysis patients.

Comparison of Clinical Outcome Between Twice-Weekly and Thrice-Weekly Hemodialysis in Patients With Residual Kidney Function

Residual kidney function (RKF) contributes to improved survival in hemodialysis (HD) patients. However, it is not clear whether RKF allows a comparable survival rate in patients undergoing twice-weekly HD compared with thrice-weekly HD.We enrolled 685 patients from a prospective multicenter observational cohort. RKF and HD adequacy was monitored regularly over 3-year follow-up. Patients with RKF were divided into groups undergoing twice-weekly HD (n = 113) or thrice-weekly HD (n = 137). Patients without RKF undergoing thrice-weekly HD (n = 435) were included as controls. Fluid balance and dialysis-associated characteristics were followed and clinical outcomes evaluated using all-cause mortality and cardiovascular events (CVE).In patients with RKF, baseline and follow-up RKF were significantly higher in patients undergoing twice-weekly HD than in those undergoing thrice-weekly HD. Total Kt/V urea (dialysis plus residual renal) in patients with RKF undergoing twice-weekly HD was greater than or equal to those in patients with or without RKF undergoing thrice-weekly HD. Compared with patients with RKF undergoing thrice-weekly HD, patients with RKF undergoing twice-weekly HD had no fluid excess, but their normalized protein catabolic rate became lower since 24-month follow up. In multivariable analyses, patients with RKF undergoing twice-weekly HD had a noninferior risk of mortality (hazard ratio [HR], 0.83; 95% confidence interval [95% CI], 0.34-2.01, P = 0.68) and of CVE (HR, 0.60; 95% CI, 0.28-1.29, P = 0.19) compared with patients without RKF undergoing thrice-weekly HD. However, this group showed an independent association with a greater risk of mortality compared with patients with RKF undergoing thrice-weekly HD (HR, 4.20; 95% CI, 1.02-17.32, P = 0.04).In conclusion, patients with RKF undergoing twice-weekly HD had an increased risk of mortality compared with those undergoing thrice-weekly HD. Decisions about twice-weekly HD should consider not only RKF, but also other risk factors such as normalized protein catabolic rate.

High-sensitivity C-reactive protein, apolipoproteins, and residual diuresis in chronic kidney disease patients undergoing hemodialysis

BACKGROUND

Residual diuresis (RD) is the simplest method for measuring renal residual function in patients with chronic kidney disease (CKD). A reduction in RD is associated with intensification of the inflammatory process caused by uremia. However, little is known regarding the relation between RD and inflammatory markers in these patients. We verify possible associations among the hs-CRP, atherogenic factors, and RD, in patients with CKD undergoing hemodialysis.

METHODS

This study enrolled 80 patients with CKD undergoing hemodialysis. Patients were stratified according to RD in anuric (RD-) group (n = 47) and non-anuric (RD+) group (n = 33). Urine volumes were collected in a 24 h period during the interdialytic period. Serum high-sensitivity C-reactive protein (hs-CRP), and apolipoprotein (Apo) A1 and B levels were measured after fasting for 12 h.

RESULTS

Serum hs-CRP levels were higher in the RD- group than in the RD+ group (P = 0.015). In the total group, hs-CRP was significantly correlated with RD (r = - 0.25, P = 0.025) and Apo AI (r = - 0.25, P = 0.024). A greater proportion of patients had reduced plasma concentrations of Apo AI in the RD- group (31.9 %) compared with the RD+ group (9.1 %) (P = 0.014).

CONCLUSION

This study shows a relationship between RD and the hs-CRP in patients undergoing hemodialysis. Although the inflammatory state was verified in a large part of the CKD population, patients without RD had more elevated hs-CRP serum levels than those with RD.

How Can We Improve the Quality of Life of Dialysis Patients?

As medical advances are made in the care of persons with chronic illnesses including those with end-stage renal disease (ESRD), patients are not only experiencing increasing life expectancy but also bearing the burden of illness and treatment for a longer duration of time. With this in mind, it is increasingly important for health care providers to pay close attention to their individual patient's perceptions of their health, fitness, life satisfaction, and well-being. This assessment of Health-Related Quality of Life (HRQOL) also includes an evaluation of the patient's level of satisfaction with treatment, outcome, and health status, also taking into account their perspective on future prospects. In addition to improving patient-provider communication by helping in the identification and prioritization of problems, it is important to note that high HRQOL has been shown to be associated with better medical outcomes, including reduction in hospitalizations and death. In this review, we outline several validated tools that are used to quantitatively measure HRQOL in the ESRD population and incorporate these instruments in a review of specific, evidence-based measures by which we can measurably improve health-related quality of life in dialysis patients.

Family income is associated with quality of life in patients with chronic kidney disease in the pre-dialysis phase: a cross sectional study

BACKGROUND

Chronic kidney disease (CKD) is a condition of high prevalence in the general population mainly due to hypertension and diabetes mellitus. It is often associated with a high prevalence of complications and worse quality of life. The main objective of this study is to evaluate quality of life (QOL) using the generic instrument SF-36 in patients with CKD in pre-dialysis and identify the possible influence of the degree of renal function, hemoglobin level, age, gender, family income and level of education on QOL.

METHODS

A cross-sectional study was conducted and included 170 individuals (83 men) with a mean age of 57 ± 15 years who met the inclusion criteria and answered the SF-36. Laboratory tests and clinical and demographic data were obtained, and the glomerular filtration rate was estimated using the CKD-EPI formula.

RESULTS

The degree of renal function did not influence QOL. Women had lower scores in functional capacity, physical aspects, pain, and mental health. Patients younger than 47 years old showed better QOL in the functional capacity; however, their QOL was worse in terms of social aspects. Subjects with an income higher than 5.1 times the minimum wage had better QOL in the functional capacity, pain, social, physical and emotional roles, and mental health. Hemoglobin levels and education did not globally influence QOL.

CONCLUSION

Gender and age influenced QOL, but family income was the most important factor affecting QOL (6 out of 8 domains investigated by SF-36) in this sample of 170 individuals with CKD in pre-dialysis. These findings suggest that many efforts should be made to reduce the effect of these factors on quality of life in patients with CKD and reinforce the need for longitudinal studies and intervention.

Intradialytic Blood Pressure Abnormalities: The Highs, The Lows and All That Lies Between

BACKGROUND

Frequent blood pressure (BP) measurements are necessary to ensure patient safety during hemodialysis treatments. Intradialytic BPs are not optimal tools for hypertension diagnosis and cardiovascular risk stratification, but they do have critical clinical and prognostic significance. We present evidence associating intradialytic BP phenomena including fall, rise and variability with adverse clinical outcomes and review related pathophysiologic mechanisms and potential management strategies.

SUMMARY

Observational studies demonstrate associations between intradialytic hypotension, hypertension and BP variability and mortality. Lack of consensus regarding diagnostic criteria has hampered data synthesis, and prospective studies investigating optimal management strategies for BP phenomena are lacking. Mechanistic data suggest that cardiac, gut, kidney and brain ischemia may lie on the causal pathway between intradialytic hypotension and mortality, and endothelial cell dysfunction, among other factors, may be an important mediator of intradialytic hypertension and adverse outcomes. These plausible pathophysiologic links present potential therapeutic targets for future inquiry. The phenomenon of intradialytic BP variability has not been adequately studied, and practical clinical measures and treatment strategies are lacking.

KEY MESSAGES

Intradialytic BP phenomena have important prognostic bearing. Clinical practice guidelines for both intradialytic hypotension and hypertension exist, but their underlying evidence is weak overall. Further research is needed to develop consensus diagnostic criteria for intradialytic hypotension, hypertension and BP variability and to elucidate optimal treatment and prevention strategies for each BP manifestation.

Progressive Hemodialysis: Is It The Future?

Progressive hemodialysis is based on the simple idea of adjusting its dose according to residual renal function (RRF). The progressive, infrequent paradigm is slowly gaining a foothold among nephrologists, despite a lot of skepticism in the scientific world. Given the importance of RRF preservation in conservative therapy, it seems a contradiction to ignore the contribution of RRF when patients initiate hemodialysis (HD), especially when it is routinely considered with peritoneal dialysis. While a three-times-weekly HD regimen is broadly considered the standard starting regimen for new patients, twice-weekly HD has been used in selected patients and is currently a common practice in South-East Asia. Small studies indicate that a once-weekly HD regimen may be a viable starting option as well. Progressive hemodialysis still requires validation, yet it is promising. We share the belief that a randomized clinical trial to investigate progressive hemodialysis is much needed, but we also strongly recommend including a once-weekly HD starting dose as part of any such investigation.

Is peritoneal dialysis still an equal option? Results of the Berlin pediatric nocturnal dialysis program

BACKGROUND

Peritoneal dialysis (PD) or conventional hemodialysis (HD) are considered to be equally efficient dialysis methods in children and adolescents. The aim of our study was to analyze whether an intensified, nocturnal HD program (NHD) is superior to PD in an adolescent cohort.

METHODS

Thirteen patients were prospectively enrolled in a NHD program. We measured uremia-associated parameters, parameters for nutrition, medication and blood pressure and analyzed the data. These data were compared to those of 13 PD controls, matched for gender, age and weight at the beginning the respective dialysis program and after 6 months of treatment.

RESULTS

Serum phosphate levels decreased significantly in the NHD group and remained unchanged in the PD group. Arterial blood pressure in the NHD was significantly lower despite the reduction of antihypertensive treatment, whereas blood pressure levels remained unchanged in the PD controls. Preexisting left ventricular hypertrophy resolved and albumin levels improved with NHD. Dietary restrictions could be lifted for those on NHD, whereas they remained in place for the patients on PD treatment. Residual diuresis remained unchanged after 6 months of either NHD or PD. NHD patients experienced fewer days of hospitalization than the PD controls.

CONCLUSIONS

Based on our results, NHD results in significantly improved parameters of uremia and nutrition. If individually and logistically possible, NHD should be the treatment modality of preference for older children and adolescents.

Preserving residual renal function in dialysis: what we know

Residual renal function confers a survival benefit among dialysis patients thought to be related to greater volume removal and solute clearance. Whether the presence of residual renal function is protective or merely a marker for better health is not clear. The basic mechanisms governing the decline or persistence of residual renal function are poorly understood and few studies have examined the role of medical therapy in its preservation. Dialysis modality, inflammatory processes often associated with comorbid diseases (including diabetes mellitus and obesity), volume dysregulation, and vitamin D deficiency are predictive of residual renal function decline. We review potential mechanisms for preservation of remaining glomerular filtration rate among chronic dialysis patients.

Association of initial twice-weekly hemodialysis treatment with preservation of residual kidney function in ESRD patients

BACKGROUND

Residual kidney function (RKF) has consistently been a predictor of greater survival in maintenance hemodialysis (MHD) patients. The relationship between hemodialysis (HD) treatment frequency and RKF preservation has not been well examined. We hypothesized that initial twice-weekly HD helps in maintaining a longer RKF.

METHODS

In a dialysis center in Shanghai, 168 ESRD patients were screened and finally 85 patients were identified for this main cohort study. We first examined these 85 MHD patients; 30 of them were initiated with twice-weekly HD for 6 months or longer and 55 patients were started and maintained on thrice-weekly HD treatment. Then a subcohort study in 48 incident MHD patients was implemented to assess the independent risk factors responsible for RKF decline during the first year of HD therapy. Multivariate logistic regression analysis was then employed to examine the odds ratio of RKF loss.

RESULTS

The main cohort study showed that the clinical outcomes were almost the same between the two groups in 85 patients, but the percent of patients with RKF loss was significantly lower in the twice-weekly group compared with the thrice-weekly group, especially during the first year of HD initiation. In the 48 incident MHD patients, we found no significant differences between the two groups except for variations in the HD frequency, weekly Kt/V. The multivariate analysis showed that factors such as the male gender, HD frequency, URR and intradialytic hypotension episode were associated with RKF loss, and the odds ratio of RKF loss for each additional HD treatment per week was 7.2.

CONCLUSION

Twice-weekly HD during the first year of dialysis therapy appears to be associated with better RKF preservation.

Timing of nephrology referral and initiation of dialysis as predictors for survival in hemodialysis patients: 5-year follow-up analysis

BACKGROUND

A consensus about the optimal timing of dialysis initiation is still controversial. Thus, the goal of this analysis was to compare outcomes in patients with early and late referral with early and late initiation of hemodialysis (HD).

METHODS

We studied 190 patients (mean age 52.03±14.22) who were initiated on HD between 1994 and 2004. Patients who received regular nephrology care during 12 months before HD initiation were categorized as early referrals (ER) and those without nephrology care were late referrals (LR). The early start (E-start) was defined by the estimated GFR (eGFR) at start of HD≥7.5 mL/min/1.73 m2, and the late start (L-start) by eGFR of <7.5 mL/min/1.73 m2. The four groups of patients (ER with E-start and L-start; LR with E-start and L-start) were prospectively followed in the next 60 months after HD initiation.

RESULTS

During the follow-up, 43.3% of E-start and 43.2% of L-start patients died, without significant difference in survival between the groups [HR for L-start vs. E-start=1.06 (95% CI 0.69-1.62); p=0.797]. When survival between ER and LR groups was compared (28.1% patients in the ER and 53.2% in the LR died), there was significant difference in survival [HR for LR vs. ER=2.16 (95% CI 1.28-3.65); p=0.004]. Compared with patients with ER and L-start, higher mortality was observed among those with LR and L-start [HR 3.51 (95% CI 1.48-8.35); p=0.004] and LR with E-start [HR 2.79 (95% CI 1.16-6.7); p=0.022]. There was no significant difference between patients in ER with L-start and ER with E-start.

CONCLUSIONS

Our study showed that ER above 12 months before HD initiation and L-start of dialysis was associated with a reduced mortality risk in HD patients.

Twice-weekly and incremental hemodialysis treatment for initiation of kidney replacement therapy

Mortality is highest in the first months of maintenance hemodialysis (HD) therapy. In many Western countries, patients who transition to kidney replacement therapy usually begin thrice-weekly HD regardless of their level of residual kidney function (RKF). RKF is a major predictor of survival. RKF may decline more rapidly with thrice-weekly HD treatments, is associated with a reduced need for dialytic solute clearance, and is an important factor in the prescription of peritoneal dialysis. In this article, we review the concept of incremental HD, in which weekly dialysis dose, in particular HD treatment frequency, is based on a variety of clinical factors, such as RKF (including urine output > 0.5 L/d), volume status, cardiovascular symptoms, body size, potassium and phosphorus levels, nutritional status, hemoglobin level, comorbid conditions, hospitalizations, and health-related quality of life. These 10 clinical criteria may identify which patients might benefit from beginning maintenance HD therapy twice weekly. Periodic monitoring of these criteria will determine the timing for increasing dialysis dose and frequency. We recognize that twice-weekly HD represents a major paradigm shift for many clinicians and jurisdictions. Therefore, we propose conducting randomized controlled trials of twice-weekly versus thrice-weekly HD to assess the potential of twice-weekly HD to improve survival and health-related quality of life while simultaneously reducing costs, protecting fragile vascular accesses, and optimizing resource use during the first year of hemodialysis therapy. Such incremental and individualized HD therapy may prove to be the most appropriate approach for transitioning to dialytic therapy.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for preserving residual kidney function in peritoneal dialysis patients

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) are widely used in peritoneal dialysis (PD) patients, yet controversy exists about their impact on residual kidney function.

OBJECTIVES

This review aimed to evaluate the benefits and harms of ACEis and ARBs for preserving residual kidney function in PD patients.

SEARCH METHODS

The Cochrane Renal Group's specialised register, Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE (OvidSP interface), Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI) and other resources were searched by applying a prespecified comprehensive search strategy. Date of last search: 01 May 2014.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing ACEis or ARBs with placebo, other antihypertensive drugs or each other in PD patients were included.

DATA COLLECTION AND ANALYSIS

Screening, selection, data extraction and quality assessments for each retrieved article were carried out by two authors using standardised forms. Authors were contacted when published data were incomplete. Statistical analyses were performed using the random effects model and results expressed as risk ratio (RR) with 95% confidence intervals (CI). Heterogeneity among studies was explored using the Cochran Q statistic and the I² test, subgroup analyses and random effects meta-regression.

MAIN RESULTS

Six open-label studies (257 patients) were identified. One study compared ACEi with other antihypertensive drugs, three compared ARBs with other antihypertensive drugs, and two studies compared an ARB with an ACEi. Long-term use (≥ 12 months) of an ARB showed significantly benefit of preserving residual kidney function in continuous ambulatory PD (CAPD) patients (MD 1.11 mL/min/1.73 m², 95% CI 0.38 to 1.83), although there was no significant benefit when an ARB were used short-term (≤ six months). One study showed that compared with other antihypertensive drugs, long-term use (12 months) of the ACEi ramipril showed a significant reduction in the decline of residual kidney function in patients on CAPD (MD -0.93 mL/min/1.73m², 95% CI -0.75 to -0.11), and delayed the progression to complete anuria (RR 0.64, 95% CI 0.41 to 0.99). There was no significant difference in serum potassium, urinary protein excretion, Kt/V, weekly creatinine clearance and blood pressure for ARBs versus other antihypertensive drugs. Compared with other antihypertensive drugs, ramipril showed no difference in mortality and cardiovascular events. Compared with an ACEi, ARBs did not show any difference in residual kidney function.The selection bias assessment was low in four studies and unclear in two. Five studies were open-label; however the primary outcome (residual kidney function) was obtained objectively from laboratory tests, and were not likely to be influenced by the lack of blinding. Reporting bias was unclear in all six studies.

AUTHORS' CONCLUSIONS

Compared with other antihypertensive drugs, long-term use (≥ 12 months) of ACEis or ARBs showed additional benefits of preserving residual kidney function in CAPD patients. There was no significant difference on residual kidney function preservation between ARBs and ACEis. However, limited by the small number of RCTs enrolling small number of participants, there is currently insufficient evidence to support the use of an ACEi or an ARB as first line antihypertensive therapy in PD patients.

Dose of hemodialysis and survival: a marginal structural model analysis

BACKGROUND

Observational studies have consistently demonstrated the survival benefits of a greater dialysis dose in maintenance hemodialysis (MHD) patients, whereas randomized controlled trials have shown conflicting results. The possible causal impact of dialysis dose on mortality needs to be investigated using rich cohort data analyzed with novel statistical methods such as marginal structural models (MSMs) that account for time-varying confounding and exposure.

METHODS

We quantified the effect of delivered dose of hemodialysis (HD) [single-pool Kt/V (spKt/V)] on mortality risk in a contemporary cohort of 68,110 patients undergoing HD 3 times weekly (7/2001- 9/2005). We compared conventional Cox proportional hazard and MSM survival analyses, accounting for time-varying confounding by applying longitudinally modeled inverse-probability-of-dialysis-dose weights to each observation.

RESULTS

In conventional Cox models, baseline spKt/V showed a weak negative association with mortality, while higher time-averaged spKt/V was strongly associated with lower mortality risk. In MSM analyses, compared to a spKt/V range of 1.2 - <1.4, a spKt/V range of <1.2 was associated with a higher risk of mortality [HR (95% CI) 1.67 (1.54 - 1.80)], whereas mortality risks were significantly lower with higher spKt/V [HRs (95% CI): 0.74 (0.70-0.78), 0.63 (0.59-0.66), 0.56 (0.52-0.60), and 0.56 (0.52-0.61) for spKt/V ranges of 1.4 - <1.6, 1.6-<1.8, 1.8 - <2.0, and ≥2.0, respectively]. Thus, MSM analyses showed that the greatest survival advantage of a higher dialysis dose was observed for a spKt/V range of 1.8-<2.0, and the dialysis dose-mortality relationship was robust in almost all subgroups of patients.

CONCLUSIONS

Higher HD doses were robustly associated with greater survival in MSM analyses that more fully and appropriately accounted for time-varying confounding.

Significance of residual renal function for phosphate control in chronic hemodialysis patients

Background

The aim of this study was to compare mineral metabolism between anuric and nonanuric chronic hemodialysis patients, and determine the differences in phosphate control between the two groups.

Methods

A total of 77 chronic hemodialysis patients were enrolled in this cross-sectional study from January 2012 to February 2012. Patient demographics, laboratory findings, medication histories, and vascular calcification scores were collected. We divided the patients into anuric and nonanuric groups according to the residual renal function and then compared their clinical features. Multivariate binary regression analysis was used in each group to determine the independent factors related to phosphate control.

Results

The mean patient age was 59.27±13.95 years, and 57.1% of patients were anuric. In anuric patients, dialysis vintage was significantly longer, but the mean Kt/V was not different between groups. Serum phosphate, fibroblast growth factor (FGF)-23, and Ca/P products were significantly higher, and 1,25(OH)₂D₃ levels were significantly lower in the anuric patients, although the intact parathyroid hormone and 25(OH)D levels were not different. In anuric patients, LnFGF-23 [hazard ratio (HR) 2.894, 95% confidence interval (CI) 1.294–6.474, P=0.010] was an independent factor predictive of phosphate control. However, in the nonanuric patients, glomerular filtration rate (HR 0.409, 95% CI 0.169–0.989, P=0.047) and blood urea nitrogen (HR 1.090, 95% CI 1.014–1.172, P=0.019) were independent factors predictive of phosphate control.

Conclusion

In chronic hemodialysis patients, preservation of residual renal function is a significant determinant of phosphate control, and the factors associated with phosphate control is different depending on the residual renal function status. In the anuric patients, FGF-23 is most significantly associated with phosphate control; however, glomerular filtration rate and blood urea nitrogen are more important than FGF-23 in the nonanuric HD patients.

[Extracellular hydration status and residual urinary sodium excretion in chronic hemodialysis patients: a cross-sectional multicenter study]

BACKGROUND

In dialysis patients, a misevaluation of dry weight may lead to an increased morbidity and mortality. The aim of this cross-sectional multicenter study was to evaluate the association between residual urinary sodium excretion and extracellular volume status in chronically treated hemodialysis patients.

PATIENTS AND METHODS

Dry weight was determined clinically and by whole-body bioimpedance spectroscopy (Body Composition Monitor, Fresenius Medical Care) prior to a mid-week session in 40 chronic hemodialysis patients with significant residual diuresis (more than 250 mL per day) and receiving treatment in four dialysis centers. Regarding their hydration status assessed by the Body Composition Monitor and in comparison to a healthy reference population, patients were assigned to 1 of the 3 categories: overhydrated, normohydrated and dehydrated. Urine output, urinary sodium excretion and residual renal function were measured for all patients within 30 days before dry weight assessment.

RESULTS

The median post-HD session FO was of-0.40 L (IQR: from-1.95 to+0.90) and the median residual urinary sodium excretion was of 64 mmol/L (IQR: 46-79). Among these patients, 16 were normohydated, 16 were dehydrated and 8 were overhydrated. There was a linear relationship between the hydration status after HD session and the urinary sodium excretion (estimate: 5.6±1.5; p<0.001). Compared with normohydrated patients, overhydrated patients had a higher residual urinary sodium excretion (estimate: 26±10; p<0.01).

CONCLUSION

In this study, urinary sodium excretion is associated with the hydration status evaluated by whole-body bioimpedance spectroscopy.

Clinical predictors of decline in nutritional parameters over time in ESRD

BACKGROUND AND OBJECTIVES

Inflammation and malnutrition are important features in patients with ESRD; however, data on changes in these parameters over time are scarce. This study aimed to gain insight into changes over time in serum albumin, body mass index, high-sensitivity C-reactive protein, and IL-6 in patients with ESRD and aimed to identify clinical risk factors for deterioration of these parameters.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were analyzed from the Convective Transport Study, a randomized controlled trial conducted from June 2004 to January 2011, in which 714 patients with chronic ESRD were randomized to either online hemodiafiltration or low-flux hemodialysis. Albumin and body mass index were measured up to 6 years and predialysis C-reactive protein and IL-6 were measured up to 3 years in a subset of 405 participants. Rates of change in these parameters over time were estimated across strata of predefined risk factors with linear mixed-effects models.

RESULTS

Albumin and body mass index decreased and C-reactive protein and IL-6 increased over time. For every incremental year of age at baseline, the yearly excess decline in albumin was 0.003 g/dl (-0.004 to -0.002; P<0.001) and the excess decline in body mass index was 0.02 kg/m(2) per year (-0.02 to -0.01; P<0.001). In patients with diabetes mellitus, there was a yearly excess decline of 0.05 g/dl in albumin (-0.09 to -0.02; P=0.002). Compared with women, men had an excess decline of 0.03 g/dl per year in albumin (-0.06 to -0.001; P=0.05) and an excess increase of 11.6% per year in IL-6 (0.63%-23.6%; P=0.04).

CONCLUSIONS

Despite guideline-based care, all inflammatory and nutritional parameters worsened over time. The deterioration of some of these parameters was more pronounced in men, older patients, and patients with diabetes mellitus. Special focus on the nutritional status of at-risk patients by individualizing medical care might improve their prognosis.

Serum concentrations of p-cresyl sulfate and indoxyl sulfate, but not inflammatory markers, increase in incident peritoneal dialysis patients in parallel with loss of residual renal function

BACKGROUND

High serum concentrations of the protein-bound uremic retention solutes p-cresyl sulfate (PCS) and indoxyl sulfate (IndS) and inflammation are associated with increased cardiovascular morbidity and mortality in chronic kidney disease. Renal clearance contributes to up to 80% of the total clearance of PCS and IndS in peritoneal dialysis (PD) patients. Cross-sectional studies evaluating the impact of residual renal function (RRF) on serum concentrations of PCS, IndS, and circulating inflammatory markers have yielded conflicting results. ♢

METHODS

To clarify this issue, we carried out a prospective observational cohort study in incident PD patients (n = 35; 19 men; mean age: 55 ± 17 years). Midday blood samples were collected and analyzed for total serum PCS, IndS, C-reactive protein, and high-sensitivity interleukin 6. Peritoneal and renal clearances were calculated from urine and dialysate collections, and RRF was calculated as the mean of renal urea nitrogen and creatinine clearances. Patients were assessed 1, 6, 12, and 24 months after PD start. Differences between time points were analyzed using linear mixed models (LMMs). ♢

RESULTS

Residual renal function declined significantly over time (LMM p < 0.0001). Peritoneal clearances of both toxins tended to increase, but did not compensate for the declining renal clearances. Serum concentrations of PCS and IndS increased significantly over time (LMM p = 0.01; p = 0.0009). In contrast, total mass removal of both toxins remained stable. Circulating inflammatory markers did not change over time. ♢

CONCLUSIONS

Our data indicate that serum concentrations of PCS and IndS, but not inflammatory markers, increase in incident PD patients in parallel with loss of RRF.

Predialysis health, dialysis timing, and outcomes among older United States adults

Studies of dialysis initiation timing have not accounted for predialysis clinical factors that could impact postdialysis outcomes. We examined the association of predialysis health with timing of dialysis initiation in older adult patients in the United States and contrasted morbidity and mortality outcomes among patients with early [estimated GFR (eGFR)≥10 ml/min per 1.73 m(2)] versus later (eGFR<10 ml/min per 1.73 m(2)) initiation. We included all patients from the US Renal Data System who initiated dialysis between 2006 and 2008, were ≥67 years old, and had ≥2 years of prior Medicare coverage (n=84,654). We calculated patients' propensity to initiate dialysis early and matched patients by propensity scores. Cox models were used to compare risks of mortality and hospitalization among initiation groups. The majority (58%) of patients initiated dialysis early. Early initiators were more likely to have had AKI, multiple congestive heart failure admissions, and other hospitalizations preceding initiation. Among propensity-matched patients (n=61,930), early initiation associated with greater all-cause (hazard ratio [HR], 1.11; 95% confidence interval [95% CI], 1.08 to 1.14), cardiovascular (CV; HR, 1.13; 95% CI, 1.09 to 1.17), and infectious (HR, 1.13; 95% CI, 1.06 to 1.22) mortality and greater all-cause (HR, 1.03; 95% CI, 1.01 to 1.05) and infectious (HR, 1.10; 95% CI, 1.07 to 1.13) hospitalizations. There was no difference in CV hospitalizations. Among these older adults, early dialysis initiation associates with greater mortality and hospitalizations, even after accounting for predialysis clinical factors. These findings do not support the common practice of early dialysis initiation in the United States.

Infrequent dialysis: a new paradigm for hemodialysis initiation

Nearly a half-century ago, the thrice-weekly hemodialysis schedule was empirically established as a means to provide an adequate dialysis dose while also treating the greatest number of end-stage renal disease (ESRD) patients using limited resources. Landmark trials of hemodialysis adequacy have historically been anchored to thrice-weekly regimens, but a recent randomized controlled trial demonstrated that frequent hemodialysis (six times per week) confers cardiovascular and survival benefits. Based on these collective data and experience, clinical practice guidelines advise against a less than thrice-weekly treatment schedule in patients without residual renal function, yet provide limited guidance on the optimal treatment frequency when substantial native kidney function is present. Thus, during the transition from Stage 5 chronic kidney disease to ESRD, the current paradigm is to initiate hemodialysis on a "full-dose" thrice-weekly regimen even among patients with substantial residual renal function. However, emerging data suggest that frequent hemodialysis accelerates residual renal function decline, and infrequent regimens may provide better preservation of native kidney function. Given the high mortality rates during the first 6 months of hemodialysis and the survival benefits of preserved native kidney function, initiation with twice-weekly treatment schedules ("infrequent hemodialysis") with an incremental increase in frequency over time may provide an opportunity to optimize patient survival. This review outlines the clinical benefits of post-hemodialysis residual renal function, studies of twice-weekly treatment regimens, and the potential risks and benefits of infrequent hemodialysis.

A comparative effectiveness research study of the change in blood pressure during hemodialysis treatment and survival

It is not clear to what extent changes in blood pressure (BP) during hemodialysis affect or predict survival. Studying comparative outcomes of BP changes during hemodialysis can have major clinical implications including the impact on management strategies in hemodialysis patients. Here we undertook a retrospective cohort study of 113,255 hemodialysis patients over a 5 year period to evaluate an association between change in BP during hemodialysis and mortality. The change in BP was defined as post- minus pre-hemodialysis BP and mean of BP change values during the hemodialysis session was used as a mortality predictor. The patients averaged 61 years old and consisted of 45% women, 32% African-Americans and 58% diabetics. Over a median follow-up of 2.2 years, a total of 53,461 (47.2%) all-cause and 21,548 (25.7%) cardiovascular deaths occurred. In fully adjusted Cox regression model with restricted cubic splines, there was a U-shaped association between change systolic BP and all-cause mortality. Post-dialytic drops in systolic BP between −30 to 0 mmHg were associated with greater survival, but large decreases of systolic BP (more than −30 mmHg) and any increase in systolic BP (over 0 mmHg) were related to increased mortality. Peak survival was found at a change in systolic BP of −14 mmHg. The U-shaped association was also found for cardiovascular mortality. Thus, modest declines in BP after hemodialysis are associated with the greatest survival, whereas any rise or large decline in BP is associated with worsened survival.

Cohort profile: Canadian study of prediction of death, dialysis and interim cardiovascular events (CanPREDDICT)

Background

The Canadian Study of Prediction of Death, Dialysis and Interim Cardiovascular Events (CanPREDDICT) is a large, prospective, pan-Canadian, cohort study designed to improve our understanding of determinants of renal and cardiovascular (CV) disease progression in patients with chronic kidney disease (CKD). The primary objective is to clarify the associations between traditional and newer biomarkers in the prediction of specific renal and CV events, and of death in patients with CKD managed by nephrologists. This information could then be used to better understand biological variation in outcomes, to develop clinical prediction models and to inform enrolment into interventional studies which may lead to novel treatments.

Methods/Designs

Commenced in 2008, 2546 patients have been enrolled with eGFR between 15 and 45 ml/min 1.73m2 from a representative sample in 25 rural, urban, academic and non academic centres across Canada. Patients are to be followed for an initial 3 years at 6 monthly intervals, and subsequently annually. Traditional biomarkers include eGFR, urine albumin creatinine ratio (uACR), hemoglobin (Hgb), phosphate and albumin. Newer biomarkers of interest were selected on the basis of biological relevance to important processes, commercial availability and assay reproducibility. They include asymmetric dimethylarginine (ADMA), N-terminal pro-brain natriuretic peptide (NT-pro-BNP), troponin I, cystatin C, high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL6) and transforming growth factor beta 1 (TGFβ1). Blood and urine samples are collected at baseline, and every 6 monthly, and stored at −80°C. Outcomes of interest include renal replacement therapy, CV events and death, the latter two of which are adjudicated by an independent panel.

Discussion

The baseline distribution of newer biomarkers does not appear to track to markers of kidney function and therefore may offer some discriminatory value in predicting future outcomes. The granularity of the data presented at baseline may foster additional questions.

The value of the cohort as a unique resource to understand outcomes of patients under the care of nephrologists in a single payer healthcare system cannot be overstated. Systematic collection of demographic, laboratory and event data should lead to new insights.

The mean age of the cohort was 68 years, 90% were Caucasian, 62% were male, and 48% had diabetes. Forty percent of the cohort had eGFR between 30–45 mL/min/1.73m², 22% had eGFR values below 20 mL/min/1.73m²; 61% had uACR < 30. Serum albumin, hemoglobin, calcium and 25-hydroxyvitamin D (25(OH)D) levels were progressively lower in the lower eGFR strata, while parathyroid hormone (PTH) levels increased. Cystatin C, ADMA, NT-proBNP, hsCRP, troponin I and IL-6 were significantly higher in the lower GFR strata, whereas 25(OH)D and TGFβ1 values were lower at lower GFR. These distributions of each of the newer biomarkers by eGFR and uACR categories were variable.

Effects of high efficiency post-dilution on-line hemodiafiltration or conventional hemodialysis on residual renal function and left ventricular hypertrophy

PURPOSE

Residual renal function (RRF) contributes to dialysis adequacy, quality of life and survival of hemodialysis patients. There is an ongoing debate whether better preservation of residual renal function is the result of chronic fluid volume overload. Our prospective investigation analyzed the effects of different dialytic therapies on RRF and left ventricular hypertrophy, which may be considered--at least in part--a surrogate marker of chronic fluid overload.

METHODS

Two cohorts of end-stage renal disease patients initiating renal replacement therapy (high efficiency post-dilution on-line hemodiafiltration (HDF) in 58 patients, conventional hemodialysis (HD) in 60 patients) were prospectively followed up. RRF was determined at baseline, 12 and 24 months, left ventricular mass index (LVMI) at baseline and after 24 months.

RESULTS

Demographic and renal characteristics, medication or exposure to nephrotoxins were comparable among the two cohorts of patients. RRF declined in all patients throughout the 2-year study period. In HDF patients, the decline was less pronounced (28 %) than in conventional HD patients (68 %). More patients undergoing HD received cardio- and renoprotective antihypertensive drugs. CRP levels were significantly higher in conventional HD. Hypotensive episodes were fewer in HDF. LVMI decreased in 90 % of HDF compared to only 25 %of HD patients.

CONCLUSIONS

Our data clearly indicate that better preservation of RRF by high efficiency hemodiafiltration is not associated with left ventricular hypertrophy.

Predictors of quality of life of hemodialysis patients in India

Little is known about the quality of life and survival in the patients on maintenance hemodialysis (HD) in India. Poor nutrition and dialysis noncompliance is common. This study investigates the factors that affect the quality of life (QoL) in HD patients in India. This cross-sectional study included 78 patients on HD for ≥ two months. Demographic, nutritional, functional subjective global assessment and Kidney Disease Quality of Life (KDQOL-36) assessments were done. Predictors of QoL were assessed by regression analysis. The mean calorie and protein intake were 1245 ± 116.9 kcal and 0.86 ± 0.19 g/kg/day respectively. Male gender (OR = 9.68), serum parathyroid hormone PTH <150 pg/ml (OR = 0.03), age ≤65 years (OR = 1.25), no catheter use (OR = 1.9) and hospitalizations (OR = 0.11), were independent predictors of total score ≥50. Independent predictors of physical component summary (PCS) >25 were male gender (OR = 5.06) and urine output at start of dialysis (OR = 1.05). Independent predictors of mental component summary (MCS) ≥25 were male gender (OR = 11.02), serum PTH > 150 pg/ml (OR = 0.15), daily protein intake of >0.8 g/kg and caloric intake >20 K.cal/kg (OR = 10.8). Patients with urine output >1 liter per day had more hypotensive episodes during dialysis (r = 0.56, P = 0.045), more headaches (r = 0.63, P = 0.006) but that did not affect the PCS significantly. Low PTH (<150 pg/ml) (OR = 1.29), multiple access failures (OR = 3.36) and total score ≤50 (OR = 0.09) were independently associated with increased hospitalization. Males, patients with serum PTH >150 pg/ml and those not on catheter had better total score. Though patients with higher urine output had better PCS, those with output >1 liter had higher incidence of hypotension and dialysis-related headache. Protein-energy malnutrition affected the MCS significantly. Dialysis noncompliance seen in one-fourth of the population did not affect the scores significantly.

The impact of an "acute dialysis start" on the mortality attributed to the use of central venous catheters: a retrospective cohort study

Background

Central venous catheters (CVCs) are associated with early mortality in dialysis patients. However, some patients progress to end stage renal disease after an acute illness, prior to reaching an estimated glomerular filtration rate (eGFR) at which one would expect to establish alternative access (fistula/peritoneal dialysis catheter). The purpose of this study was to determine if exclusion of this “acute start” patient group alters the association between CVCs and mortality.

Methods

We conducted a retrospective cohort study of 406 incident dialysis patients from 1 Jan 2006 to 31 Dec 2009. Patients were classified as acute starts if 1) the eGFR was >25 ml/min/1.73 m², ≤3 months prior to dialysis initiation and declined after an acute event (n = 45), or 2) in those without prior eGFR measurements, there was no supporting evidence of chronic kidney disease on history or imaging (n = 12). Remaining patients were classified as chronic start (n = 349).

Results

98 % and 52 % of acute and chronic starts initiated dialysis with a CVC. There were 148 deaths. The adjusted mortality hazard ratio (HR) for acute vs. chronic start patients was 1.84, (95 % CI [1.19-2.85]). The adjusted mortality HR for patients dialyzing with a CVC compared to alternative access was 1.19 (95 % CI [0.80-1.77]). After excluding acute start patients, the adjusted HR fell to 1.03 (95 % CI [0.67-1.57]).

Conclusions

A significant proportion of early dialysis mortality occurs after an acute start. Exclusion of this population attenuates the mortality risk associated with CVCs.

Native nephrectomy prior to pediatric kidney transplantation: biological and clinical aspects

BACKGROUND

Pre-transplant nephrectomy is performed to reduce risks to graft and recipient. The aims of this study were to evaluate (1) indications, surgical approach, and morbidity of native nephrectomy and (2) the effects of kidney removal on clinical and biological parameters.

METHODS

This study was designed as a single-center retrospective cohort study in which 49 consecutive patients with uni- or bilateral native nephrectomies were identified from a total of 126 consecutive graft recipients in our pediatric kidney transplantation database between 1992 and 2011. Demographic, clinical, and laboratory details were extracted from charts and electronic records, including operation reports and pre- and post-operative clinic notes.

RESULTS

Of the 49 nephrectomized patients, 47% had anomalies of the kidneys and urinary tract, 22% had cystinosis, 12% had focal segmental glomerulosclerosis, and 6% had congenital nephrotic syndrome. Nephrectomy decisions were based on clinical judgment, taking physiological and psychosocial aspects into consideration. Nephrectomy was performed in patients with polyuria (>2.5 ml/kg/h) and/or large proteinuria (>40 mg/m(2)/h), recurrent urinary tract infection or (rarely) hypertension. Urine output decreased from (median) 3.79 to 2.32 ml/kg/h (-34%), and proteinuria from 157 to 100 mg/m(2)/h (-40%) after unilateral nephrectomy (p=0.005). After bilateral nephrectomy, serum albumin, protein and fibrinogen concentrations normalized in 93, 73, and 55% of nephrectomized patients, respectively. Clinically relevant procedure-related complications (peritoneal laceration, hematoma) occurred in five patients.

CONCLUSION

In summary, we demonstrate quantitatively that native nephrectomy prior to transplantation improved serum protein levels and anticipated post-transplant fluid intake needs in select children, reducing the risk of graft hypoperfusion and its postulated consequences for graft outcome.

Serum β-trace protein and risk of mortality in incident hemodialysis patients

BACKGROUND AND OBJECTIVES

Residual kidney function in dialysis patients is associated with better survival, but there are no simple methods for its assessment. β-Trace protein is a novel endogenous filtration marker of kidney function that is not removed during hemodialysis and may serve as a marker for residual kidney function similar to serum creatinine in patients not on dialysis. The objective of this study was to determine the association of serum β-trace protein with mortality in incident hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Serum β-trace protein was measured in baseline samples from 503 participants of a national prospective cohort study of incident dialysis patients with enrollment during 1995-1998 and follow-up until 2004. Outcomes were all-cause and cardiovascular disease mortality analyzed using Cox regression adjusted for demographic, clinical, and treatment factors.

RESULTS

Serum β-trace protein levels were higher in individuals with no urine output compared with individuals with urine output (9.0±3.5 versus 7.6±3.1 mg/L; P<0.001). There were 321 deaths (159 deaths from cardiovascular disease) during follow-up (median=3.3 years). Higher β-trace protein levels were associated with higher risk of mortality. The adjusted hazard ratio and 95% confidence interval for all-cause mortality per doubling of serum β-trace protein was 1.36 (1.09-1.69). The adjusted hazard ratios (95% confidence intervals) for all-cause mortality in the middle and highest tertiles compared with the lowest tertile were 0.95 (0.69-1.32) and 1.72 (1.25-2.37). Similar results were noted for cardiovascular disease mortality.

CONCLUSIONS

The serum level of β-trace protein is an independent predictor of death and cardiovascular disease mortality in incident hemodialysis patients.