Frequent Hemodialysis Network (FHN) randomized trials: Study design

Association of Bioimpedance Parameters with Increases in Blood Pressure during Hemodialysis

BACKGROUND

Intradialytic hypertension, defined as an increase in BP from pre- to post-hemodialysis (HD), affects 5%-15% of patients receiving maintenance HD and is associated with cardiovascular and all-cause mortality. Hypervolemia is believed to be a major etiological factor, yet the association of more objective biomarkers of volume status with intradialytic hypertension is not well described.

METHODS

In a post hoc analysis of the Frequent Hemodialysis Network Daily Trial ( n =234), using data from baseline, 1-, 4-, and 12-month visits ( n =800), we used random-effects regression to assess the association of bioimpedance estimates of volume (vector length) with post-HD systolic BP (continuous) and any increase in systolic BP (categorical) from pre- to post-HD. We adjusted models for randomized group; age; sex; self-reported race; Quételet (body mass) index; vascular access; HD vintage; hypertension; history of heart failure; diabetes; residual kidney function (urea clearance); pre-HD systolic BP; ultrafiltration rate; serum-dialysate sodium gradient; and baseline values of hemoglobin, phosphate, and equilibrated Kt/V urea.

RESULTS

The mean age of participants was 50±14 years, 39% were female, and 43% were Black. In adjusted models, shorter vector length (per 50 Ω/m) was associated with higher post-HD systolic BP (2.9 mm Hg; 95% confidence interval [CI], 1.6 to 4.3) and higher odds of intradialytic hypertension (odds ratio 1.66; 95% CI, 1.07 to 2.55). Similar patterns of association were noted with a more stringent definition of intradialytic hypertension (>10 mm Hg increase from pre- to post-HD systolic BP), where shorter vector length (per 50 Ω/m) was associated with a higher odds of intradialytic hypertension (odds ratio 2.17; 95% CI, 0.88 to 5.36).

CONCLUSIONS

Shorter vector length, a bioimpedance-derived proxy of hypervolemia, was independently associated with higher post-HD systolic BP and risk of intradialytic hypertension.

Interventions for fatigue in people with kidney failure requiring dialysis

BACKGROUND

Fatigue is a common and debilitating symptom in people receiving dialysis that is associated with an increased risk of death, cardiovascular disease and depression. Fatigue can also impair quality of life (QoL) and the ability to participate in daily activities. Fatigue has been established by patients, caregivers and health professionals as a core outcome for haemodialysis (HD).

OBJECTIVES

We aimed to evaluate the effects of pharmacological and non-pharmacological interventions on fatigue in people with kidney failure receiving dialysis, including HD and peritoneal dialysis (PD), including any setting and frequency of the dialysis treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 18 October 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Studies evaluating pharmacological and non-pharmacological interventions affecting levels of fatigue or fatigue-related outcomes in people receiving dialysis were included. Studies were eligible if fatigue or fatigue-related outcomes were reported as a primary or secondary outcome. Any mode, frequency, prescription, and duration of therapy were considered.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the risk of bias. Treatment estimates were summarised using random effects meta-analysis and expressed as a risk ratio (RR) or mean difference (MD), with a corresponding 95% confidence interval (CI) or standardised MD (SMD) if different scales were used. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Ninety-four studies involving 8191 randomised participants were eligible. Pharmacological and non-pharmacological interventions were compared either to placebo or control, or to another pharmacological or non-pharmacological intervention. In the majority of domains, risks of bias in the included studies were unclear or high. In low certainty evidence, when compared to control, exercise may improve fatigue (4 studies, 217 participants (Iowa Fatigue Scale, Modified Fatigue Impact Scale, Piper Fatigue Scale (PFS), or Haemodialysis-Related Fatigue scale score): SMD -1.18, 95% CI -2.04 to -0.31; I2 = 87%) in HD. In low certainty evidence, when compared to placebo or standard care, aromatherapy may improve fatigue (7 studies, 542 participants (Fatigue Severity Scale (FSS), Rhoten Fatigue Scale (RFS), PFS or Brief Fatigue Inventory score): SMD -1.23, 95% CI -1.96 to -0.50; I2 = 93%) in HD. In low certainty evidence, when compared to no intervention, massage may improve fatigue (7 studies, 657 participants (FSS, RFS, PFS or Visual Analogue Scale (VAS) score): SMD -1.06, 95% CI -1.47, -0.65; I2 = 81%) and increase energy (2 studies, 152 participants (VAS score): MD 4.87, 95% CI 1.69 to 8.06, I2 = 59%) in HD. In low certainty evidence, when compared to placebo or control, acupressure may reduce fatigue (6 studies, 459 participants (PFS score, revised PFS, or Fatigue Index): SMD -0.64, 95% CI -1.03 to -0.25; I2 = 75%) in HD. A wide range of heterogenous interventions and fatigue-related outcomes were reported for exercise, aromatherapy, massage and acupressure, preventing our capability to pool and analyse the data. Due to the paucity of studies, the effects of pharmacological and other non-pharmacological interventions on fatigue or fatigue-related outcomes, including non-physiological neutral amino acid, relaxation with or without music therapy, meditation, exercise with nandrolone, nutritional supplementation, cognitive-behavioural therapy, ESAs, frequent HD sections, home blood pressure monitoring, blood flow rate reduction, serotonin reuptake inhibitor, beta-blockers, anabolic steroids, glucose-enriched dialysate, or light therapy, were very uncertain. The effects of pharmacological and non-pharmacological treatments on death, cardiovascular diseases, vascular access, QoL, depression, anxiety, hypertension or diabetes were sparse. No studies assessed tiredness, exhaustion or asthenia. Adverse events were rarely and inconsistently reported.

AUTHORS' CONCLUSIONS

Exercise, aromatherapy, massage and acupressure may improve fatigue compared to placebo, standard care or no intervention. Pharmacological and other non-pharmacological interventions had uncertain effects on fatigue or fatigue-related outcomes in people receiving dialysis. Future adequately powered, high-quality studies are likely to change the estimated effects of interventions for fatigue and fatigue-related outcomes in people receiving dialysis.

Clinical Outcomes With Medium Cut-Off Versus High-Flux Hemodialysis Membranes: A Systematic Review and Meta-Analysis

BACKGROUND

A novel medium cut-off (MCO) dialyzer (Theranova, Baxter Healthcare, Deerfield, IL, USA) enhances large middle molecule clearance while retaining selectivity for molecules >45 000 Da.

OBJECTIVE

We undertook a systematic review and meta-analysis evaluating clinical outcomes with MCO vs high-flux membranes.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Cochrane Library, and Web of Science through July 2020, and gray literature sources from 2017. We included randomized (RS) and nonrandomized studies (NRS) comparing MCO and high-flux membranes in adults receiving maintenance hemodialysis. Pairs of reviewers performed study selection, data extraction, and risk of bias assessment in duplicate. We conducted random-effects pairwise meta-analyses to pool results across studies and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess evidence certainty.

RESULTS

We identified 22 eligible studies (6 RS, 16 NRS; N = 1811 patients; patient-years = 1546). The MCO dialyzer improved (estimate; 95% confidence interval [CI]; certainty rating) quality of life (mean difference [MD] = 16.7/100 points; 6.9 to 26.4; moderate), Kidney Disease Quality of Life Instrument (KDQOL) subscales-burden (MD = 4.0; 1.1 to 6.9; moderate) and effects (MD = 5.4; 3.2 to 7.6; moderate), pruritus (MD = -4.4; -7.1 to -1.7; moderate), recovery time (MD = -420 minutes; -541 to -299; high), and restless legs syndrome (odds ratio = 0.39; 0.29 to 0.53; moderate). There was little to no difference in all-cause mortality (risk difference = -0.4%; -2.8 to 2.1; moderate) and serious adverse events (rate ratio = 0.63; 0.38 to 1.04; low). MCO dialysis reduced hospitalization (rate ratio = 0.48; 0.27 to 0.84; low), infection (rate ratio = 0.38; 0.17 to 0.85; moderate), hospitalization days (MD = -1.5 days; 95% CI, -2.22 to -0.78; moderate), erythropoiesis resistance index (MD = -2.92 U/kg/week/g/L; 95% CI, -4.25 to -1.6; moderate) and cumulative iron use over 12 weeks (MD = -293 mg; 95% CI, -368 to -218; moderate). We found with low certainty that MCO dialysis had little to no effect on KDQOL symptoms/problem list, pain, and physical health and moderate certainty that MCO dialysis likely has no effect on the KDQOL mental health composite.

CONCLUSIONS

We found with predominantly moderate certainty that the MCO dialyzer improves several patient-important outcomes with no apparent risks or harms. More definitive studies are needed to better quantify the effects of MCO membranes on mortality, hospitalization, and other rare events.

The Predialysis Serum Sodium Level Modifies the Effect of Hemodialysis Frequency on Left-Ventricular Mass: The Frequent Hemodialysis Network Trials

INTRODUCTION

The Frequent Hemodialysis Network (FHN) Daily and Nocturnal trials aimed to compare the effects of hemodialysis (HD) given 6 versus 3 times per week. More frequent in-center HD significantly reduced left-ventricular mass (LVM), with more pronounced effects in patients with low urine volumes. In this study, we aimed to explore another potential effect modifier: the predialysis serum sodium (SNa) and related proxies of plasma tonicity.

METHODS

Using data from the FHN Daily and Nocturnal Trials, we compared the effects of frequent HD on LVM among patients stratified by SNa, dialysate-to-predialysis serum-sodium gradient (GNa), systolic and diastolic blood pressure, time-integrated sodium-adjusted fluid load (TIFL), and extracellular fluid volume estimated by bioelectrical impedance analysis.

RESULTS

In 197 enrolled subjects in the FHN Daily Trial, the treatment effect of frequent HD on ∆LVM was modified by SNa. When the FHN Daily Trial participants are divided into lower and higher predialysis SNa groups (less and greater than 138 mEq/L), the LVM reduction in the lower group was substantially higher (-28.0 [95% CI -40.5 to -15.4] g) than in the higher predialysis SNa group (-2.0 [95% CI -15.5 to 11.5] g). Accounting for GNa, TIFL also showed more pronounced effects among patients with higher GNa or higher TIFL. Results in the Nocturnal Trial were similar in direction and magnitude but did not reach statistical significance.

DISCUSSION/CONCLUSION

In the FHN Daily Trial, the favorable effects of frequent HD on left-ventricular hypertrophy were more pronounced among patients with lower predialysis SNa and higher GNa and TIFL. Whether these metrics can be used to identify patients most likely to benefit from frequent HD or other dialytic or nondialytic interventions remains to be determined. Prospective, adequately powered studies studying the effect of GNa reduction on mortality and hospitalization are needed.

Quality of Life in Caregivers of Patients Randomized to Standard- Versus Extended-Hours Hemodialysis

Introduction

Caregivers are essential for the health, safety, and independence of many patients and incur financial and personal cost in this role, including increased burden and lower quality of life (QOL) compared to the general population. Extended-hours hemodialysis may be the preference of some patients, but little is known about its effects on caregivers.

Methods

Forty caregivers of participants of the ACTIVE Dialysis trial, who were randomized to 12 months extended (median 24 hours/wk) or standard (12 hours/wk) hemodialysis, were included. Utility-based QOL was measured by EuroQOL–5 Dimension–3 Level (EQ-5D-3L) and Short Form–6 Dimensions (SF-6D) and health-related QOL (HRQOL) was measured by the 36-Item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS) and the Personal Wellbeing Index (PWI) at enrolment and then every 3 months until the end of the study.

Results

At baseline, utility-based QOL and HRQOL were similar in both groups. At follow-up, caregivers of people randomized to extended-hours dialysis experienced a greater decrease in utility-based QOL measured by EQ-5D-3L compared with caregivers of people randomized to standard hours (–0.18±0.30 vs. –0.02±0.16, P = 0.04). There were no differences between extended- and standard-hours groups in mean change in SF-6D (0.03±0.12 vs. –0.04±0.1, P = 0.8), PCS (–1.2±9.8 vs. –5.6±9.8, P = 0.2), MCS (–4.1±11.2 vs. –0.5±7.1, P = 0.4), and PWI (2.3±17.6 vs. 0.00±20.4, P = 0.9).

Conclusion

Poorer utility-based QOL, as measured by the EQ-5D-3L, was observed in caregivers of patients receiving extended-hours hemodialysis in this small study. Though the findings are exploratory, the possibility that mode of dialysis delivery negatively impacts on caregivers supports the prioritization of research on burden and impact of service delivery in this population.

Health-Related Quality of Life in Home Dialysis Patients Compared to In-Center Hemodialysis Patients: A Systematic Review and Meta-analysis

RATIONALE & OBJECTIVE

Dialysis patients judge health-related quality of life (HRQoL) as an essential outcome. Remarkably, little is known about HRQoL differences between home dialysis and in-center hemodialysis (HD) patients worldwide.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & STUDY POPULATIONS

Search strategies were performed on the Cochrane Library, Pubmed, and EMBASE databases between 2007 and 2019. Home dialysis was defined as both peritoneal dialysis and home HD.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials and observational studies that compared HRQoL in home dialysis patients versus in-center HD patients.

DATA EXTRACTION

The data extracted by 2 authors included HRQoL scores of different questionnaires, dialysis modality, and subcontinent.

ANALYTICAL APPROACH

Data were pooled using a random-effects model and results were expressed as standardized mean difference (SMD) with 95% CIs. Heterogeneity was explored using subgroup analyses.

RESULTS

Forty-six articles reporting on 41 study populations were identified. Most studies were cross-sectional in design (90%), conducted on peritoneal dialysis patients (95%), and used the 12-item or 36-item Short-Form Health Survey questionnaires (83%). More than half the studies showed moderate or high risk of bias. Pooled analysis of 4,158 home dialysis patients and 7,854 in-center HD patients showed marginally better physical HRQoL scores in home dialysis patients compared with in-center HD patients (SMD, 0.14; 95% CI, 0.04 to 0.24), although heterogeneity was high (I 2>80%). In a subgroup analysis, Western European home dialysis patients had higher physical HRQoL scores (SMD, 0.39; 95% CI, 0.17 to 0.61), while home dialysis patients from Latin America had lower physical scores (SMD, -0.20; 95% CI, -0.28 to -0.12). Mental HRQoL showed no difference in all analyses.

LIMITATIONS

No randomized controlled trials were found and high heterogeneity among studies existed.

CONCLUSIONS

Although pooled data showed marginally better physical HRQoL for home dialysis patients, the quality of design of the included studies was poor. Large prospective studies with adequate adjustments for confounders are necessary to establish whether home dialysis results in better HRQoL.

TRIAL REGISTRATION

PROSPERO 95985.

Evaluation of one year of frequent dialysis on fluid load and body composition using calf bioimpedance technique

OBJECTIVE

The primary aim of this study was to evaluate the effect of increased frequency of dialysis (FHD) on change in fluid status and body composition using segmental bioimpedance.

APPROACH

Twelve stable HD patients were switched from 3 times/week to 6 times/week HD (FHD). Systolic blood pressure (SBP), body mass and body mass index (BMI) were measured pre- and post-HD. Calf resistance (R ₅) at 5 kHz was measured using a multifrequency bioimpedance device (Hydra 4200). Calf resistivity (ρ  =  R ₅ * area/length), normalized resistivity (CNR  =  ρ/BMI) and calf extracellular volume (cECV) were calculated. Fat mass was measured by Futrex body composition analyzers (Futrex 6100, Futrex Tech, Inc.). All measurements were performed at baseline (BL) and monthly for up to one year.

MAIN RESULTS

Nine patients completed one year of FHD. Compared to BL, body weight and cECV decreased, and CNR increased significantly by the first month but did not change thereafter. SBP pre-HD decreased significantly by the end of the first month with further reduction until month 12. Additionally, antihypertensive medication decreased significantly from baseline by month 4 and remained stable from month 6 throughout the rest of the study. The post-HD CNR in five of nine patients reached the range of normal (>18.5 10^-2 * Ohm * m³ kg^-1 for males and  >19.1 10^-2 * Ohm * m³ kg^-1 for females) after 1 year FHD. In patients who returned to 3 times/week dialysis, CNR decreased significantly in the first week, and this was associated with increases in body weight and SBP.

SIGNIFICANCE

Reduction of fluid overload with no alteration of body composition was observed in this study. Accordingly, improving fluid status was confirmed by reducing BP and use of antihypertensive drugs together with increase in CNR. Measurement of fluid status by CNR in hemodialysis patients is a new method to quantitatively assess hydration potentially creating a target for volume of fluid removal.

The effect of increased frequency of hemodialysis on vitamin C concentrations: an ancillary study of the randomized Frequent Hemodialysis Network (FHN) daily trial

BACKGROUND

Reports on vitamin C in HD patients have shown effects of vitamin C deficiency in association with scurvy symptoms. Dialyzability of water soluble vitamins is high, and substantial losses in those who are dialyzed more frequently were hypothesized. The randomized FHN Daily Trial compared the effects of in-center HD six versus three times per week. We studied baseline correlations between vitamin C and potentially associated parameters, and the effect of more frequent HD on circulating vitamin C concentrations.

METHODS

We studied vitamin C levels at baseline and months, 3, 5 and 11. Patients enrolled between 2007 and 2009 into the randomized FHN Daily trial in the East Coast consortium were approached for participation. Predialysis plasma samples were processed with metaphosphoric acid and frozen at - 70 °C for measurement with HPLC. Regression models between baseline log-transformed vitamin C and hemoglobin, CRP, eKt/V, ePCR and PTH, and a linear mixed-effects model to estimate the effect size of more frequent HD on plasma vitamin C, were constructed.

RESULTS

We studied 44 subjects enrolled in the FHN Daily trial (50 ± 12 years, 36% female, 29% Hispanics and 64% blacks, 60% anuric). Vitamin C correlated significantly with predialysis hemoglobin (r = 0.3; P = 0.03) and PTH (r = - 0.3, P = 0.04), respectively. Vitamin C did not significantly differ at baseline (6×/week, 25.8 ± 25.9 versus 3×/week, 32.6 ± 39.4 μmol/L) and no significant treatment effect on plasma vitamin C concentrations was found [- 26.2 (95%CI -57.5 to 5.1) μmol/L at Month 4 and - 2.5 (95%CI -15.6 to 10.6) μmol/L at Month 12.

CONCLUSIONS

Based on data from this large randomized-controlled trial no significant effect of the intervention on circulating plasma vitamin C concentrations was found, allaying the concerns that more frequent HD would affect the concentrations of water-soluble vitamins and adversely affect patient's well-being. Correlations between vitamin C and hemoglobin and PTH support the importance of vitamin C for normal bone and mineral metabolism, and anemia management.

A need for a paradigm shift in focus: From Kt/Vurea to appropriate removal of sodium (the ignored uremic toxin)

Hemodialysis for chronic renal failure was introduced and developed in Seattle, WA, in the 1960s. Using Kiil dialyzers, weekly dialysis time and frequency were established to be about 30 hours on 3 time weekly dialysis. This dialysis time and frequency was associated with 10% yearly mortality in the United States in 1970s. Later in 1970s, newer and more efficient dialyzers were developed and it was felt that dialysis time could be shortened. An additional incentive to shorten dialysis was felt to be lower cost and higher convenience. Additional support for shortening dialysis time was provided by a randomized prospective trial performed by National Cooperative Dialysis Study (NCDS). This study committed a Type II statistical error rejecting the time of dialysis as an important factor in determining the quality of dialysis. This study also provided the basis for the establishment of the Kt/V_urea index as a measure of dialysis adequacy. This index having been established in a sacrosanct randomized controlled trial (RCT), was readily accepted by the HD community, and led to shorter dialysis, and higher mortality in the United States. Kt/V_urea is a poor measure of dialysis quality because it combines three unrelated variables into a single formula. These variables influence the clinical status of the patient independent of each other. It is impossible to compensate short dialysis duration (t) with the increased clearance of urea (K), because the tolerance of ultrafiltration depends on the plasma-refilling rate, which has nothing in common with urea clearance. Later, another RCT (the HEMO study) committed a Type III statistical error by asking the wrong research question, thus not yielding any valuable results. Fortunately, it did not lead to deterioration of dialysis outcomes in the United States. The third RCT in this field ("in-center hemodialysis 6 times per week versus 3 times per week") did not bring forth any valuable results, but at least confirmed what was already known. The fourth such trial ("The effects of frequent nocturnal home hemodialysis") too did not show any positive results primarily due to significant subject recruitment issues leading to inappropriate selection of patients. Comparison of the value of peritoneal dialysis and HD in RCTs could not be completed because of recruitment problems. Randomized controlled trials have therefore failed to yield any meaningful information in the area of dose and or frequency of hemodialysis.

Changes in Biomarker Profile and Left Ventricular Hypertrophy Regression: Results from the Frequent Hemodialysis Network Trials

BACKGROUND

Regression of left ventricular hypertrophy (LVH) is feasible with more frequent hemodialysis (HD). We aimed to ascertain pathways associated with regression of left ventricular mass (LVM) in patients enrolled in the Frequent HD Network (FHN) trials.

METHODS

This was a post hoc observational cohort study. We hypothesized LVH regression with frequent HD was associated with a different cardiovascular biomarker profile. Regressors were defined as patients who achieved a reduction of more than 10% in LVM at 12 months. Progressors were defined as patients who had a minimum of 10% increase in LVM at 12 months.

RESULTS

Among 332 randomized patients, 243 had biomarker data available. Of these, 121 patients did not progress or regress, 77 were regressors, and 45 were progressors. Mean LVM change differed between regressors and progressors by -65.6 (-74.0 to -57.2) g, p < 0.001. Regressors had a median (interquartile range) increase in dialysis frequency (from 3.0 [3.0-3.0] to 4.9 [3-5.7] per week, p = 0.001) and reductions in pre-dialysis systolic (from 149.0 [136.0-162.0] to 136.0 [123.0-152.0] mm Hg, p < 0.001) and diastolic (from 83.0 [71.0-91.0] to 76.0 [68.0-84.0] mm Hg, p < 0.001) blood pressures. Klotho levels increased in regressors versus progressors (76.9 [10.5-143.3] pg/mL, p = 0.024). Tissue inhibitors of metalloproteinase (TIMP)-2 levels fell in regressors compared to progressors (-7,853 [-14,653 to -1,052] pg/mL, p = 0.024). TIMP-1 and log (brain natriuretic -peptide [BNP]) levels also tended to fall in regressors. Changes in LVM correlated inversely with changes in klotho (r = -0.24, p = 0.014). -Conclusions: Markers of collagen turnover and changes in klotho levels are potential novel pathways associated with regression of LVH in the dialysis population, which will require further prospective validation.

Home haemodialysis in Ireland

BACKGROUND

Home haemodialysis (HHD) has the potential to impact positively on patient outcomes and health resource management. There has been rejuvenated international interest in HHD in recent years.

AIM

We aimed to review the activity and outcomes of the Irish HHD Programme since inception (2009-16).

DESIGN

Retrospective review.

METHODS

Patient data were collected using the national electronic Renal Patient database (eMEDRenal version 3.2.1) and individual centre records. All data were recorded in a coded fashion on a Microsoft Excel Spread-sheet and analysed with Stata SE software.

RESULTS

One hundred and one patients completed training and commenced HHD; a further fourty-five patients were assessed for HHD suitability but did not ultimately dialyse at home. Twenty patients switched to nocturnal HHD when this resource became available. The switch from conventional in-centre dialysis to HHD led to an increase in the mean weekly hours on haemodialysis (HD) and a reduction in medication burden for the majority of patients. The overall rate of arteriovenous fistula (AVF) as primary vascular access was 62%. Most HHD complications were related to access function or access-related infection. Over the 7-years, 29 HHD patients were transplanted and 9 patients died. No deaths resulted directly from a HHD complication or technical issue.

CONCLUSIONS

Patient and technique survival rates compared favourably to published international reports. However, we identified several aspects that require attention. A small number of patients were receiving inadequate dialysis and require targeted education. Ongoing efforts to increase AVF and self-needling rates in HD units must continue. Psychosocial support is critical during the transition between dialysis modalities.

When is more frequent hemodialysis beneficial?

The use of frequent hemodialysis (HD) is growing, with the hope of improving outcomes in end-stage renal disease. We narratively review the three randomized trials, 15 comparative cohort studies, and several case series of frequent HD that empirically demonstrate the potential efficacy and adverse effects of these regimens. Taken together, the randomized studies suggest frequent HD may result in left ventricular mass regression. This effect is most pronounced when left ventricular mass is abnormal, but attenuated by significant residual urine output. Both frequent short and long HD consistently improved blood pressure control and reduced antihypertensive use, despite greater weekly interdialytic weight gains. Serum phosphate was lowered. Frequent short daytime HD improved health-related quality of life, while frequent long overnight HD did not. Regarding adverse effects, frequent HD patients underwent significantly more procedures to salvage arteriovenous vascular accesses. An absolute increase in hypotensive episodes was observed with frequent short HD, while frequent long HD accelerated residual renal function loss and increased perceived caregiver burden. The effect of frequent HD on mortality is controversial, due to conflicting results and limitations of published studies. Finally, pregnancy outcomes may be substantially better with frequent long HD. On the basis of these data, we suggest frequent HD is most likely to benefit patients with left ventricular hypertrophy particularly if there is minimal urine output, those unable to attain dry weight on a thrice weekly schedule, and pregnant women. All patients receiving frequent HD should be advised of and monitored for potential risks.

Association between change in serum bicarbonate and change in thyroid hormone levels in patients receiving conventional or more frequent maintenance haemodialysis

AIM

Correction of metabolic acidosis in patients with chronic kidney disease has been associated with improvement in thyroid function. We examined whether changes in bicarbonate were associated with changes in thyroid function in patients with end-stage renal disease receiving conventional or more frequent haemodialysis.

METHODS

In the Frequent Hemodialysis Network Trials, the relationship between changes in serum bicarbonate, free triiodothyronine (FT3) and free thyroxine (FT4) was examined among 147 and 48 patients with endogenous thyroid function who received conventional (3×/week) or more frequent (6×/week) haemodialysis (Daily Trial) or who received conventional or more frequent nocturnal haemodialysis (Nocturnal Trial). Equilibrated normalized protein catabolic rate (enPCR) was examined to account for nutritional factors affecting both acid load and thyroid function.

RESULTS

Increasing dialysis frequency was associated with increased bicarbonate level. Baseline bicarbonate level was not associated with baseline FT3 and FT4. Change in bicarbonate level was not associated with changes in FT3 and FT4 in the Daily Trial nor for FT4 in the Nocturnal Trial (r ≤ 0.14, P > 0.21). While, a significant correlation between change in serum bicarbonate and change in FT3 (r = 0.44, P = 0.02) was observed in the Nocturnal Trial; findings were no longer significant after adjusting for change in enPCR (r = 0.37, P = 0.08). For participants with baseline bicarbonate <23 mmol/L, no association between change in bicarbonate and change in thyroid indices were seen in the Daily Trial; for the Nocturnal Trial, findings were also not significant for change in FT3 and the association between change in bicarbonate and change in FT4 (r = 0.54, P = 0.03) was no longer significant after adjusting for enPCR (r = 0.45, P = 0.11).

CONCLUSION

Changes in bicarbonate were not associated with changes in thyroid hormone levels after adjusting for enPCR, as a marker of nutritional status. Future studies should examine whether improvement in acid base status improves thyroid function in haemodialysis patients with evidence of thyroid hypofunction.

Intensive Hemodialysis and Potential Risks With Increasing Treatment

Although intensive hemodialysis (HD) can address important clinical problems, increasing treatment also introduces risks. In this review, we assess risks pertaining to 6 domains: vascular access complications, infection, mortality, loss of residual kidney function, solute balance, and patient and care partner burden. In the Frequent Hemodialysis Network (FHN) trials, short daily and nocturnal schedules increased the incidence of access complications, although the incidence of access loss was not statistically higher. Observational studies indicate that infection-related hospitalization is an ongoing challenge with short daily HD. Excess risk may be catalyzed by poor infection control practices in the home setting in which intensive HD is typically delivered, but with fixed probability of bacterial contamination per cannulation, greater treatment frequency necessarily increases the risk for infectious complications. Buttonhole cannulation may increase the risk for metastatic infections. However, intensive HD in the home setting is associated with lower risk for infection than peritoneal dialysis. Data regarding mortality are equivocal. With extended follow-up of individuals in the FHN trials, short daily HD was associated with lower risk relative to the usual schedule, whereas nocturnal HD was associated with higher risk. In many, but not all, observational studies, short daily HD has been associated with lower risk than both in-center HD and peritoneal dialysis; however, observational studies are subject to unmeasured confounding. Intensive HD can accelerate the loss of residual kidney function in new dialysis patients with substantial urine output and can deplete solutes (eg, phosphorus) to the extent that supplementation is necessary. Finally, intensive HD may increase burden on patients and caregivers, possibly leading to technique failure. Some of these problems might be addressed with careful monitoring, so that relevant interventions (eg, antibiotics, retraining, and respite care) can be delivered. Ultimately, intensive HD is not a panacea for end-stage renal disease. Potential benefits and risks of treatment should be jointly considered.

Effects of Different Models of Dialysis Care on Patient-Important Outcomes: A Systematic Review and Meta-Analysis

Ongoing payment reform in dialysis necessitates better patient outcomes and lower costs. Suggested improvements to processes of care for maintenance dialysis patients are abundant; however, their impact on patient-important outcomes is unclear. This systematic review included comparative randomized controlled trials or observational studies with no restriction on language, published from 2000 to 2014, involving at least 5 adult dialysis patients who received a minimum of 6 months of follow-up. The effect size was pooled and stratified by intervention strategy (multidisciplinary care [MDC], home dialysis, alternate dialysis settings, and electronic health record implementation). Heterogeneity (I²) was used to assess the variability in study effects related to study differences rather than chance. Of the 1988 articles screened, 25 international studies with 74,833 maintenance dialysis patients were included. Interventions with MDC or home dialysis were associated with a lower mortality (hazard ratio [HR] = 0.72, 95% confidence interval [CI] 0.61, 0.84, I² = 41.6%; HR = 0.57, 95% CI 0.41, 0.81, I² = 89.0%; respectively) and hospitalizations (incidence rate ratio [IRR] = 0.68, 95% CI 0.51, 0.91, I² = NA; IRR = 0.88, 95% CI 0.64, 1.20, I² = 79.6%; respectively). Alternate dialysis settings also were associated with a reduction in hospitalizations (IRR = 0.41, 95% CI 0.25, 0.69, I² = 0.0%). This systematic review underscores the importance of multidisciplinary care, and also the value of telemedicine as a means to increase access to providers and enhance outcomes for those dialyzing at home or in alternate settings, including those with limited access to nephrology expertise because of travel distance.

Thyroid function in end stage renal disease and effects of frequent hemodialysis

INTRODUCTION

End-stage renal disease (ESRD) is associated with perturbations in thyroid hormone concentrations and an increased prevalence of hypothyroidism. Few studies have examined the effects of hemodialysis dose or frequency on endogenous thyroid function.

METHODS

Within the Frequent Hemodialysis Network (FHN) trials, we examined the prevalence of hypothyroidism in patients with ESRD. Among those with endogenous thyroid function (without overt hyper/hypothyroidism or thyroid hormone supplementation), we examined the association of thyroid hormone concentration with multiple parameters of self-reported health status, and physical and cognitive performance, and the effects of hemodialysis frequency on serum thyroid stimulating hormone (TSH), free thyroxine (FT4), and free tri-iodothyronine (FT3) levels. Conventional thrice-weekly hemodialysis was compared to in-center (6 d/wk) hemodialysis (Daily Trial) and Nocturnal (6 nights/wk) home hemodialysis (Nocturnal Trial) over 12 months.

FINDINGS

Among 226 FHN Trial participants, the prevalence of hypothyroidism was 11% based on thyroid hormone treatment and/or serum TSH ≥8 mIU/mL. Among the remaining 195 participants (147 Daily, 48 Nocturnal) with endogenous thyroid function, TSH concentrations were modestly (directly) correlated with age (r = 0.16, P = 0.03) but not dialysis vintage. Circulating thyroid hormone levels were not associated with parameters of health status or physical and cognitive performance. Furthermore, frequent in-center and nocturnal hemodialysis did not significantly change (baseline to month 12) TSH, FT4, or FT3 concentrations in patients with endogenous thyroid function.

DISCUSSION

Among patients receiving hemodialysis without overt hyper/hypothyroidism or thyroid hormone treatment, thyroid indices were not associated with multiple measures of health status and were not significantly altered with increased dialysis frequency.

Patients receiving frequent hemodialysis have better health-related quality of life compared to patients receiving conventional hemodialysis

Most patients with end-stage kidney disease value their health-related quality of life (HRQoL) and want to know how it will be affected by their dialysis modality. We extended the findings of two prior clinical trial reports to estimate the effects of frequent compared to conventional hemodialysis on additional measures of HRQoL. The Daily Trial randomly assigned 245 patients to receive frequent (six times per week) or conventional (three times per week) in-center hemodialysis. The Nocturnal Trial randomly assigned 87 patients to receive frequent nocturnal (six times per week) or conventional (three times per week) home hemodialysis. All patients were on conventional hemodialysis prior to randomization, with an average feeling thermometer score of 70 to 75 (a visual analog scale from 0 to 100 where 100 is perfect health), an average general health scale score of 40 to 47 (a score from 0 to 100 where 100 is perfect health), and an average dialysis session recovery time of 2 to 3 hours. Outcomes are reported as the between-treatment group differences in one-year change in HRQoL measures and analyzed using linear mixed effects models. After one year in the Daily Trial, patients assigned to frequent in-center hemodialysis reported a higher feeling thermometer score, better general health, and a shorter recovery time after a dialysis session compared to standard thrice-weekly dialysis. After one year in the Nocturnal Trial, patients assigned to frequent home hemodialysis also reported a shorter recovery time after a dialysis session, but no statistical difference in their feeling thermometer or general health scores compared to standard home dialysis schedules. Thus, patients receiving day or nocturnal hemodialysis on average recovered approximately one hour earlier from a frequent compared to conventional hemodialysis session. Patients treated in an in-center dialysis facility reported better HRQoL with frequent compared to conventional hemodialysis.

Limited reduction in uremic solute concentrations with increased dialysis frequency and time in the Frequent Hemodialysis Network Daily Trial

The Frequent Hemodialysis Network Daily Trial compared conventional three-times weekly treatment to more frequent treatment with a longer weekly treatment time in patients receiving in-center hemodialysis. Evaluation at one year showed favorable effects of more intensive treatment on left ventricular mass, blood pressure, and phosphate control, but modest or no effects on physical or cognitive performance. The current study compared plasma concentrations of uremic solutes in stored samples from 53 trial patients who received three-times weekly in-center hemodialysis for an average weekly time of 10.9 hours and 30 trial patients who received six-times weekly in-center hemodialysis for an average of 14.6 hours. Metabolomic analysis revealed that increased treatment frequency and time resulted in an average reduction of only 15 percent in the levels of 107 uremic solutes. Quantitative assays confirmed that increased treatment did not significantly reduce levels of the putative uremic toxins p-cresol sulfate or indoxyl sulfate. Kinetic modeling suggested that our ability to lower solute concentrations by increasing hemodialysis frequency and duration may be limited by the presence of non-dialytic solute clearances and/or changes in solute production. Thus, failure to achieve larger reductions in uremic solute concentrations may account, in part, for the limited benefits observed with increasing frequency and weekly treatment time in Frequent Hemodialysis Daily Trial participants.

T-Wave Alternans, Heart Rate Turbulence, and Ventricular Ectopy in Standard versus Daily Hemodialysis: Results from the FHN Daily Trial

BACKGROUND

Hemodialysis (HD) patients are at high risk of sudden cardiac death (SCD). HD 6-times/week (6x/wk) may reduce SCD risk compared to usual 3-times/week HD (3x/wk) by mechanisms unknown. T-wave alternans (TWA), heart rate turbulence (HRT), and ventricular ectopy (VE) are elevated in HD patients, but their response to 6x/wk HD has not been assessed.

METHODS

Baseline and 1-year Holter recordings were analyzed from enrollees in the Frequent Hemodialysis Network Daily Trial, a randomized trial comparing 3x/wk to 6x/wk in 245 chronic HD patients. TWA, HRT, and VE were assessed using MARS software.

RESULTS

Sixty-eight patients (34 with 6x/wk) had complete baseline and 1-year Holter recordings. Mean age was 50 ± 13 years and 38% were female. Maximum TWA in the 3x/wk and 6x/wk groups were 52.4 μV at baseline and 51.2 μV at 1-year versus 54.0 and 49.9 μV, respectively (P = 0.28). The proportion of abnormal HRT (scores of 1 or 2) in the 3x/wk group decreased from 65% to 56% at 1-year versus 53% to 53% in the 6x/wk group (P = 0.58). Mean %VE changed from 1.6% to 2.9% in the 3x/wk group from baseline to 1-year and from 2.1% to 3.7% in the 6x/wk group (P = 0.85).

CONCLUSIONS

There were no significant differences in HRT or VE at 1-year in chronic HD patients randomized to 6x/wk versus 3x/wk and a trend in TWA reduction. Additional studies are needed to evaluate the impact and mechanisms of SCD in HD.

Hyperprolactinemia in end-stage renal disease and effects of frequent hemodialysis

INTRODUCTION

End-stage renal disease is associated with elevations in circulating prolactin concentrations, but the association of prolactin concentrations with intermediate health outcomes and the effects of hemodialysis frequency on changes in serum prolactin have not been examined.

METHODS

The FHN Daily and Nocturnal Dialysis Trials compared the effects of conventional thrice weekly hemodialysis with in-center daily hemodialysis (6 days/week) and nocturnal home hemodialysis (6 nights/week) over 12 months and obtained measures of health-related quality of life, self-reported physical function, mental health and cognition. Serum prolactin concentrations were measured at baseline and 12-month follow-up in 70% of the FHN Trial cohort to examine the associations among serum prolactin concentrations and physical, mental and cognitive function and the effects of hemodialysis frequency on serum prolactin.

FINDINGS

Among 177 Daily Trial and 60 Nocturnal Trial participants with baseline serum prolactin measurements, the median serum prolactin concentration was 65 ng/mL (25th-75th percentile 48-195 ng/mL) and 81% had serum prolactin concentrations >30 ng/mL. While serum prolactin was associated with sex (higher in women), we observed no association between baseline serum prolactin and age, dialysis vintage, and baseline measures of physical, mental and cognitive function. Furthermore, there was no significant effect of hemodialysis frequency on serum prolactin in either of the two trials.

DISCUSSION

Serum prolactin concentrations were elevated in the large majority of patients with ESRD, but were not associated with several measures of health status. Circulating prolactin levels also do not appear to decrease in response to more frequent hemodialysis over a one-year period.

Comparisons of amino acids, body constituents and antioxidative response between long-time HD and normal HD

Introduction Oxidative stress is one of the main mediators of progression of chronic kidney diseases (CKD). Nuclear factor E2-related factor 2 (Nrf2) is the transcription factor of antioxidant and detoxifying enzymes and related proteins which play an important role in cellular defense. Long-time hemodialysis (HD) therapy (8 hours) has been considered to be more beneficial compared to normal HD therapy (4 hours). We investigated oxidative response related to Nrf2 in peripheral blood mononuclear cells (PBMCs) of long-time HD and normal HD patients. Methods Eight adult long-time HD therapy patients (44.5 ± 3.0 years) and 10 normal HD therapy patients (68.1 ± 2.7 years) were enrolled. PBMCs were isolated and processed for expression of Nrf2 and its related genes by qRT-PCR. Plasma indoxyl sulfate, amino acids, and body constituents were measured. Findings Plasma indoxyl sulfate was significantly low after long-time HD therapy compare to that of normal HD therapy. Although, skeletal muscle mass, lean body mass, mineral and protein were significantly decreased 2 months in normal HD patients, those in long-time HD patients were significantly increased after 2 months. Almost of amino acids were significantly decreased after HD therapy in both HD therapies. Plasma amino acids were significantly low in long-time HD patients compared to normal HD patients. In PBMCs, the expression of Nrf2 was significantly decreased and hemooxygenase-1 expression was significantly increased in long-time HD compared to normal HD. Conclusion These observations indicate the beneficial effects of in long-time HD in improving oxidative stress in patients.

Value-based integrated (renal) care: setting a development agenda for research and implementation strategies

BACKGROUND

Integrated care services are considered a vital strategy for improving the Triple Aim values for people with chronic kidney disease. However, a solid scholarly explanation of how to develop, implement and evaluate such value-based integrated renal care services is limited. The aim of this study was to develop a framework to identify the strategies and outcomes for the implementation of value-based integrated renal care.

METHODS

First, the theoretical foundations of the Rainbow Model of Integrated Care and the Triple Aim were united into one overarching framework through an iterative process of key-informant consultations. Second, a rapid review approach was conducted to identify the published research on integrated renal care, and the Cochrane Library, Medline, Scopus, and Business Source Premier databases were searched for pertinent articles published between 2000 and 2015. Based on the framework, a coding schema was developed to synthesis the included articles.

RESULTS

The overarching framework distinguishes the integrated care domains: 1) type of integration, 2) enablers of integration and the interrelated outcome domains, 3) experience of care, 4) population health and 5) costs. The literature synthesis indicated that integrated renal care implementation strategies have particularly focused on micro clinical processes and physical outcomes, while little emphasis has been placed on meso organisational as well as macro system integration processes. In addition, evidence regarding patients' perceived outcomes and economic outcomes has been weak.

CONCLUSION

These results underscore that the future challenge for researchers is to explore which integrated care implementation strategies achieve better health and improved experience of care at a lower cost within a specific context. For this purpose, this study's framework and evidence synthesis have set a developmental agenda for both integrated renal care practice and research. Accordingly, we plan further work to develop an implementation model for value-based integrated renal services.

Metabolic Profiling of Impaired Cognitive Function in Patients Receiving Dialysis

Retention of uremic metabolites is a proposed cause of cognitive impairment in patients with ESRD. We used metabolic profiling to identify and validate uremic metabolites associated with impairment in executive function in two cohorts of patients receiving maintenance dialysis. We performed metabolic profiling using liquid chromatography/mass spectrometry applied to predialysis plasma samples from a discovery cohort of 141 patients and an independent replication cohort of 180 patients participating in a trial of frequent hemodialysis. We assessed executive function with the Trail Making Test Part B and the Digit Symbol Substitution test. Impaired executive function was defined as a score ≥2 SDs below normative values. Four metabolites-4-hydroxyphenylacetate, phenylacetylglutamine, hippurate, and prolyl-hydroxyproline-were associated with impaired executive function at the false-detection rate significance threshold. After adjustment for demographic and clinical characteristics, the associations remained statistically significant: relative risk 1.16 (95% confidence interval [95% CI], 1.03 to 1.32), 1.39 (95% CI, 1.13 to 1.71), 1.24 (95% CI, 1.03 to 1.50), and 1.20 (95% CI, 1.05 to 1.38) for each SD increase in 4-hydroxyphenylacetate, phenylacetylglutamine, hippurate, and prolyl-hydroxyproline, respectively. The association between 4-hydroxyphenylacetate and impaired executive function was replicated in the second cohort (relative risk 1.12; 95% CI, 1.02 to 1.23), whereas the associations for phenylacetylglutamine, hippurate, and prolyl-hydroxyproline did not reach statistical significance in this cohort. In summary, four metabolites related to phenylalanine, benzoate, and glutamate metabolism may be markers of cognitive impairment in patients receiving maintenance dialysis.

The effect of frequent hemodialysis on self-reported sleep quality: Frequent Hemodialysis Network Trials

BACKGROUND

Many patients who receive maintenance hemodialysis experience poor sleep. Uncontrolled studies suggest frequent hemodialysis improves sleep quality, which is a strong motivation for some patients to undertake the treatment. We studied the effects of frequent in-center ('daily') and nocturnal home hemodialysis on self-reported sleep quality in two randomized trials.

METHODS

Participants were randomly assigned to frequent (six times per week) or conventional (three times per week) hemodialysis in the Frequent Hemodialysis Network Daily (n = 245) and Nocturnal (n = 87) Trials. We used the Medical Outcomes Study Sleep Problems Index II (SPI II), a validated and reliable instrument in patients with end-stage renal disease, to measure self-reported sleep quality. The SPI II is scored from 0-100, with a higher value indicating poorer quality of sleep. A mean relative decline in SPI II would suggest improved sleep quality. The primary sleep outcome was the change in the SPI II score over 12 months.

RESULTS

In the Daily Trial, after adjustment for baseline SPI II, subjects randomized to frequent as compared with conventional in-center hemodialysis experienced a 4.2 [95% confidence interval (CI) 0.4-8.0] point adjusted mean relative decline in SPI II at 4 months and a 2.6 (95% CI -2.3-7.5) point adjusted mean relative decline at 12 months. In the Nocturnal Trial, subjects randomized to frequent nocturnal as compared with conventional home hemodialysis experienced 2.9 (95% CI -3.4-9.3) and 4.5 (95% CI -3.2-12.2) point mean relative declines at Months 4 and 12, respectively.

CONCLUSIONS

Although a possible benefit of frequent in-center hemodialysis was observed at 4 months, neither frequent in-center hemodialysis nor home nocturnal hemodialysis demonstrated significant improvements in self-reported sleep quality compared with conventional hemodialysis at 12 months.

Cognitive changes associated with switching to frequent nocturnal hemodialysis or renal transplantation

Background

It is uncertain whether switching to frequent nocturnal hemodialysis improves cognitive function in well-dialyzed patients and how this compares to patients who receive a kidney transplant.

Methods

We conducted a multicenter observational study with longitudinal follow-up of the effect on cognitive performance of switching dialysis treatment modality from conventional thrice-weekly hemodialysis to frequent nocturnal hemodialysis, a functioning renal transplant or remaining on thrice-weekly conventional hemodialysis. Neuropsychological tests of memory, attention, psychomotor processing speed, executive function and fluency as well as measures of solute clearance were performed at baseline and again after switching modality. The change in cognitive performance measured by neuropsychological tests assessing multiple cognitive domains at baseline, 4 and 12 months after switching dialysis modality were analyzed using a linear mixed model.

Results

Seventy-seven patients were enrolled; 21 of these 77 patients were recruited from the randomized Frequent Hemodialysis Network (FHN) Nocturnal Trial. Of these, 18 patients started frequent nocturnal hemodialysis, 28 patients received a kidney transplant and 31 patients remained on conventional thrice-weekly hemodialysis. Forty-eight patients (62 %) returned for the 12-month follow-up. Despite a significant improvement in solute clearance, 12 months treatment with frequent nocturnal hemodialysis was not associated with substantial improvement in cognitive performance. By contrast, renal transplantation, which led to near normalization of solute clearance was associated with clinically relevant and significant improvements in verbal learning and memory with a trend towards improvements in psychomotor processing speed. Cognitive performance in patients on conventional hemodialysis remained stable with the exception of an improvement in psychomotor processing speed and a decline in verbal fluency.

Conclusions

In patients on conventional thrice-weekly hemodialysis, receiving a functioning renal transplant was associated with improvement in auditory-verbal memory and psychomotor processing speed, which was not observed after 12 months of frequent nocturnal hemodialysis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0223-9) contains supplementary material, which is available to authorized users.

Chronic Hemodialysis Therapy in the West

BACKGROUND

Chronic hemodialysis (HD) in the 1960s encompassed a wide variety of prescriptions from twice weekly to five times per week HD. Over time, HD prescriptions in the West became standardized at three times per week, 2.5-4 h per session, with occasional additional treatments for volume overload.

SUMMARY

When clinical trials of dialysis dose failed to show significant benefit of extending time compared with the traditional dialysis prescription, interest in more frequent HD was renewed. Consequently, there has been growth in home HD therapies as well as alternative dialysis prescriptions. Data from recent randomized clinical trials have demonstrated the benefits and risks of these more frequent therapies, with surprising differences in outcomes between short daily HD and long nocturnal HD. More frequent therapies improve control of both hypertension and hyperphosphatemia, but at the expense of increased vascular access complications and, at least for nocturnal HD, a faster loss of residual renal function.

KEY MESSAGES

In the West, the standard HD prescription is three treatments per week with a minimal time of 3.0 h and dialysis is performed in an outpatient dialysis center. A minority of patients will have a fourth treatment per week for volume issues. Alternative HD prescriptions, although rare, are more available compared to the recent past.

FACTS FROM EAST AND WEST

(1) While developed Western and Asian countries provide end-stage renal disease patients full access to HD, healthcare systems from South and South-East Asia can offer access to HD only to a limited fraction of the patients in need. Even though the annual costs of HD are much lower in less developed countries (for instance 30 times lower in India compared to the US), patients often cannot afford costs not covered by health insurance. (2) The recommended dialysis pattern in the West is at least three sessions weekly with high-flux dialyzers. Studies from Shanghai and Taiwan might however indicate a benefit of twice versus thrice weekly sessions. In less developed Asian countries, a twice weekly pattern is common, sometimes with dialyzer reuse and inadequate water treatment. A majority of patients decrease session frequency or discontinue the program due to financial constraint. (3) As convective therapies are gaining popularity in Europe, penetration in Asia is low and limited by costs. (4) In Asian countries, in particular in the South and South-East, hepatitis and tuberculosis infections in HD patients are higher than in the West and substantially increase mortality. (5) Progress has recently been made in countries like Thailand and Brunei to provide universal HD access to all patients in need. Nevertheless, well-trained personnel, reliable registries and better patient follow-up would improve outcomes in low-income Asian countries.

Long-Term Effects of Frequent In-Center Hemodialysis

The Frequent Hemodialysis Network Daily Trial randomized 245 patients to receive six (frequent) or three (conventional) in-center hemodialysis sessions per week for 12 months. As reported previously, frequent in-center hemodialysis yielded favorable effects on the coprimary composite outcomes of death or change in left ventricular mass and death or change in self-reported physical health. Here, we determined the long-term effects of the 12-month frequent in-center hemodialysis intervention. We determined the vital status of patients over a median of 3.6 years (10%-90% range, 1.5-5.3 years) after randomization. Using an intention to treat analysis, we compared the mortality hazard in randomized groups. In a subset of patients from both groups, we reassessed left ventricular mass and self-reported physical health a year or more after completion of the intervention; 20 of 125 patients (16%) randomized to frequent hemodialysis died during the combined trial and post-trial observation periods in contrast to 34 of 120 patients (28%) randomized to conventional hemodialysis. The relative mortality hazard for frequent versus conventional hemodialysis was 0.54 (95% confidence interval, 0.31 to 0.93); with censoring of time after kidney transplantation, the relative hazard was 0.56 (95% confidence interval, 0.32 to 0.99). Bayesian analysis suggested a relatively high probability of clinically significant benefit and a very low probability of harm with frequent hemodialysis. In conclusion, a 12-month frequent in-center hemodialysis intervention significantly reduced long-term mortality, suggesting that frequent hemodialysis may benefit selected patients with ESRD.

Non-Linear Heart Rate Variability Indices in the Frequent Hemodialysis Network Trials of Chronic Hemodialysis Patients

BACKGROUND

Non-linear heart rate variability (HRV) indices were hypothesized to correlate with cardiac function, fluid overload and physical performance in hemodialysis patients.

METHODS

Twenty-four-hour Holter electrocardiograms were recorded in patients enrolled in the Frequent Hemodialysis Network (FHN) Daily Dialysis Trial. Correlations between non-linear HRV indices and left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), extracellular volume (ECV)/total body water (TBW) ratio, the SF-36 Physical Health Composite (PHC) and Physical Functioning (PF) scores were tested.

RESULTS

We studied 210 subjects (average age 49.8 ± 13.5 years, 62% men, 42% diabetics). In non-diabetic patients, multiscale entropy (MSE) slope sample entropy (SampEn) and approximate entropy (ApEn) correlated positively with LVEF, PF and PHC and inversely with LVEDV and ECV/TBW. Spectral power slope correlated positively with ECV/TBW (r = 0.27). Irregularity measures (MSE ApEn and MSE SampEn) correlated positively with LVEDV (r = 0.19 and 0.20).

CONCLUSION

Non-linear HRV indices indicated an association between a deteriorated heart rate regulatory system and impaired cardiac function, fluid accumulation and poor physical condition.

Long-term Effects of Frequent Nocturnal Hemodialysis on Mortality: The Frequent Hemodialysis Network (FHN) Nocturnal Trial

BACKGROUND

Few data are available regarding the long-term mortality rate for patients receiving nocturnal home hemodialysis.

STUDY DESIGN

Posttrial observational study.

SETTING & PARTICIPANTS

Frequent Hemodialysis Network (FHN) Nocturnal Trial participants who consented to extended follow-up.

INTERVENTION

The FHN Nocturnal Trial randomly assigned 87 individuals to 6-times-weekly home nocturnal hemodialysis or 3-times-weekly hemodialysis for 1 year. Patients were enrolled starting in March 2006 and follow-up was completed by May 2010. After the 1-year trial concluded, FHN Nocturnal participants were free to modify their hemodialysis prescription.

OUTCOMES & MEASUREMENTS

We obtained dates of death and kidney transplantation through July 2011 using linkage to the US Renal Data System and queries of study centers. We used log-rank tests and Cox regression to relate mortality to the initial randomization assignment.

RESULTS

Median follow-up for the trial and posttrial observational period was 3.7 years. In the nocturnal arm, there were 2 deaths during the 12-month trial period and an additional 12 deaths during the extended follow-up. In the conventional arm, the numbers of deaths were 1 and 4, respectively. In the nocturnal dialysis group, the overall mortality HR was 3.88 (95% CI, 1.27-11.79; P=0.01). Using as-treated analysis with a 12-month running treatment average, the HR for mortality was 3.06 (95% CI, 1.11-8.43; P=0.03). Six-month running treatment data analysis showed an HR of 1.12 (95% CI, 0.44-3.22; P=0.7).

LIMITATIONS

These results should be interpreted cautiously due to a surprisingly low (0.03 deaths/patient-year) mortality rate for individuals randomly assigned to conventional home hemodialysis, low statistical power for the mortality comparison due to the small sample size, and the high rate of hemodialysis prescription changes.

CONCLUSIONS

Patients randomly assigned to nocturnal hemodialysis had a higher mortality rate than those randomly assigned to conventional dialysis. The implications of this result require further investigation.

Effects of frequent hemodialysis on blood pressure: Results from the randomized frequent hemodialysis network trials

Hypertension is a common complication of chronic kidney disease and persists among most patients with end-stage renal disease despite the provision of conventional thrice weekly hemodialysis (HD). We analyzed the effects of frequent HD on blood pressure in the randomized controlled Frequent Hemodialysis Network trials. The daily trial randomized 245 patients to 12 months of 6× ("frequent") vs. 3× ("conventional") weekly in-center hemodialysis; the nocturnal trial randomized 87 patients to 12 months of 6× weekly nocturnal HD vs. 3× weekly predominantly home-based hemodialysis. In the daily trial, compared with 3× weekly HD, 2 months of frequent HD lowered predialysis systolic blood pressure by -7.7 mmHg [95% confidence interval (CI): -11.9 to -3.5] and diastolic blood pressure by -3.9 mmHg [95% CI: -6.5 to -1.3]. In the nocturnal trial, compared with 3× weekly HD, 2 months of frequent HD lowered systolic blood pressure by -7.3 mmHg [95% CI: -14.2 to -0.3] and diastolic blood pressure by -4.2 mmHg [95% CI: -8.3 to -0.1]. In both trials, blood pressure treatment effects were sustained until month 12. Frequent HD resulted in significantly fewer antihypertensive medications (daily: -0.36 medications [95% CI: -0.65 to -0.08]; nocturnal: -0.44 mediations [95% CI: -0.89 to -0.03]). In the daily trial, the relative risk per dialysis session for intradialytic hypotension was lower with 6×/week HD but given the higher number of sessions per week, there was a higher relative risk for intradialytic hypotensive requiring saline administration. In summary, frequent HD reduces blood pressure and the number of prescribed antihypertensive medications.

Home versus in-centre haemodialysis for end-stage kidney disease

BACKGROUND

Home haemodialysis is associated with improved survival and quality of life in uncontrolled studies. However, relative benefits and harms of home versus in-centre haemodialysis in randomised controlled trials (RCTs) are uncertain.

OBJECTIVES

To evaluate the benefits and harms of home haemodialysis versus in-centre haemodialysis in adults with end-stage kidney disease (ESKD).

SEARCH METHODS

The Cochrane Renal Group's Specialised Register was searched up to 31 October 2014.

SELECTION CRITERIA

RCTs of home versus in-centre haemodialysis in adults with ESKD were included.

DATA COLLECTION AND ANALYSIS

Data were extracted by two investigators independently. Study risk of bias and other patient-centred outcomes were extracted. Insufficient data were available to conduct meta-analyses.

MAIN RESULTS

We identified a single cross-over RCT (enrolling 9 participants) that compared home haemodialysis (long hours: 6 to 8 hours, 3 times/week) with in-centre haemodialysis (short hours: 3.5 to 4.5 hours, 3 times/weeks) for 8 weeks in prevalent home haemodialysis patients. Outcome data were limited and not available for the end of the first phase of treatment in this cross-over study which was at risk of bias due to differences in dialysate composition between the two treatment comparisons.Overall, home haemodialysis reduced 24 hour ambulatory blood pressure and improved uraemic symptoms, but increased treatment-related burden of disease and interference in social activities. Insufficient data were available for mortality, hospitalisation or dialysis vascular access complications or treatment durability.

AUTHORS' CONCLUSIONS

Insufficient randomised data were available to determine the effects of home haemodialysis on survival, hospitalisation, and quality of life compared with in-centre haemodialysis. Given the consistently observed benefits of home haemodialysis on quality of life and survival in uncontrolled studies, and the low prevalence of home haemodialysis globally, randomised studies evaluating home haemodialysis would help inform clinical practice and policy.

Agreement of single- and multi-frequency bioimpedance measurements in hemodialysis patients: an ancillary study of the Frequent Hemodialysis Network Daily Trial

BACKGROUND

Bioimpedance analysis (BIA) is well established to assess body composition. Agreements between single- and multi-frequency bioimpedance (SF-BIA, MF-BIS) measurements in subjects undergoing 6 or 3 times/week hemodialysis (HD) were analyzed.

METHODS

Total body water (TBW) and intra- and extracellular fluid (ICF, ECF) of subjects enrolled in the Frequent Hemodialysis Network (FHN) Daily Trial (www.clinicaltrials.gov No. NCT00264758) were measured with a Hydra 4200 at baseline (BL) and at 5 months (M5). Volumes were computed using SF (at 50 kHz) and MF approaches. Agreement was assessed by means of linear regression and Bland-Altman analysis and treatment effects by t test.

RESULTS

35 subjects (17 on the more frequent regimen, 26 males, 20 African-American, 48 ± 9 years, pre-HD weight 84 ± 19 kg) were studied. Assessments with SF-BIA and MF-BIS correlated significantly at BL and M5 in both arms. No proportional errors, but systematic biases over the entire range of values were found at BL and M5. Agreement did not differ between subjects randomized to either HD treatment arm at both time points. MF-BIS appears to have better precision than SF-BIA allowing the observation of a significant treatment effect by the intervention [-1.5 (95% CI -2.5 to -0.5) l] on ECF, not found for ECF SF-BIA. Precision also affected the statistical power of the SF-BIA data in the current analysis.

CONCLUSION

Both methods showed agreement without significant proportional errors regardless of HD frequency and can be used for longitudinal analyses. SF-BIA has lower precision which needs thorough consideration in the design of future trials with similar outcomes.

Cerebro-renal interactions: impact of uremic toxins on cognitive function

Cognitive impairment (CI) associated with chronic kidney disease (CKD) has received attention as an important problem in recent years. Causes of CI with CKD are multifactorial, and include cerebrovascular disease, renal anemia, secondary hyperparathyroidism, dialysis disequilibrium, and uremic toxins (UTs). Among these causes, little is known about the role of UTs. We therefore selected 21 uremic compounds, and summarized reports of cerebro-renal interactions associated with UTs. Among the compounds, uric acid, indoxyl sulfate, p-cresyl sulfate, interleukin 1-β, interleukin 6, TNF-α, and PTH were most likely to affect the cerebro-renal interaction dysfunction; however, sufficient data have not been obtained for other UTs. Notably, most of the data were not obtained under uremic conditions; therefore, the impact and mechanism of each UT on cognition and central nervous system in uremic state remains unknown. At present, impacts and mechanisms of UT effects on cognition are poorly understood. Clarifying the mechanisms and establishing novel therapeutic strategies for cerebro-renal interaction dysfunction is expected to be subject of future research.

Effects of frequent hemodialysis on perceived caregiver burden in the Frequent Hemodialysis Network trials

BACKGROUND AND OBJECTIVES

Patients receiving hemodialysis often perceive their caregivers are overburdened. We hypothesize that increasing hemodialysis frequency would result in higher patient perceptions of burden on their unpaid caregivers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In two separate trials, 245 patients were randomized to receive in-center daily hemodialysis (6 days/week) or conventional hemodialysis (3 days/week) while 87 patients were randomized to receive home nocturnal hemodialysis (6 nights/week) or home conventional hemodialysis for 12 months. Changes in overall mean scores over time in the 10-question Cousineau perceived burden scale were compared.

RESULTS

In total, 173 of 245 (70%) and 80 of 87 (92%) randomized patients in the Daily and Nocturnal Trials, respectively, reported having an unpaid caregiver at baseline or during follow-up. Relative to in-center conventional dialysis, the 12-month change in mean perceived burden score with in-center daily hemodialysis was -2.1 (95% confidence interval, -9.4 to +5.3; P=0.58). Relative to home conventional dialysis, the 12-month change in mean perceived burden score with home nocturnal dialysis was +6.1 (95% confidence interval, -0.8 to +13.1; P=0.08). After multiple imputation for missing data in the Nocturnal Trial, the relative difference between home nocturnal and home conventional hemodialysis was +9.4 (95% confidence interval, +0.55 to +18.3; P=0.04). In the Nocturnal Trial, changes in perceived burden were inversely correlated with adherence to dialysis treatments (Pearson r=-0.35; P=0.02).

CONCLUSION

Relative to conventional hemodialysis, in-center daily hemodialysis did not result in higher perceptions of caregiver burden. There was a trend to higher perceived caregiver burden among patients randomized to home nocturnal hemodialysis. These findings may have implications for the adoption of and adherence to frequent nocturnal hemodialysis.

Effects of daily hemodialysis on heart rate variability: results from the Frequent Hemodialysis Network (FHN) Daily Trial

BACKGROUND

End-stage renal disease is associated with reduced heart rate variability (HRV), components of which generally are associated with advanced age, diabetes mellitus and left ventricular hypertrophy. We hypothesized that daily in-center hemodialysis (HD) would increase HRV.

METHODS

The Frequent Hemodialysis Network (FHN) Daily Trial randomized 245 patients to receive 12 months of six versus three times per week in-center HD. Two hundred and seven patients had baseline Holter recordings. HRV measures were calculated from 24-h Holter electrocardiograms at both baseline and 12 months in 131 patients and included low-frequency power (LF, a measure of sympathetic modulation), high-frequency power (HF, a measure of parasympathetic modulation) and standard deviation (SD) of the R-R interval (SDNN, a measure of beat-to-beat variation).

RESULTS

Baseline to Month 12 change in LF was augmented by 50% [95% confidence interval (95% CI) 6.1-112%, P =0.022] and LF + HF was augmented by 40% (95% CI 3.3-88.4%, P = 0.03) in patients assigned to daily hemodialysis (DHD) compared with conventional HD. Changes in HF and SDNN were similar between the randomized groups. The effects of DHD on LF were attenuated by advanced age and diabetes mellitus (predefined subgroups). Changes in HF (r = -0.20, P = 0.02) and SDNN (r = -0.18, P = 0.04) were inversely associated with changes in left ventricular mass (LVM).

CONCLUSIONS

DHD increased the LF component of HRV. Reduction of LVM by DHD was associated with increased vagal modulation of heart rate (HF) and with increased beat-to-beat heart rate variation (SDNN), suggesting an important functional correlate to the structural effects of DHD on the heart in uremia.

Effects of frequent hemodialysis on ventricular volumes and left ventricular remodeling

BACKGROUND AND OBJECTIVES

Higher left ventricular volume is associated with death in patients with ESRD. This work investigated the effects of frequent hemodialysis on ventricular volumes and left ventricular remodeling.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Frequent Hemodialysis Network daily trial randomized 245 patients to 12 months of six times per week versus three times per week in-center hemodialysis; the Frequent Hemodialysis Network nocturnal trial randomized 87 patients to 12 months of six times per week nocturnal hemodialysis versus three times per week predominantly home-based hemodialysis. Left and right ventricular end systolic and diastolic volumes, left ventricular mass, and ejection fraction at baseline and end of the study were ascertained by cardiac magnetic resonance imaging. The ratio of left ventricular mass/left ventricular end diastolic volume was used as a surrogate marker of left ventricular remodeling. In each trial, the effect of frequent dialysis on left or right ventricular end diastolic volume was tested between predefined subgroups.

RESULTS

In the daily trial, frequent hemodialysis resulted in significant reductions in left ventricular end diastolic volume (-11.0% [95% confidence interval, -16.1% to -5.5%]), left ventricular end systolic volume (-14.8% [-22.7% to -6.2%]), right ventricular end diastolic volume (-11.6% [-19.0% to -3.6%]), and a trend for right ventricular end systolic volume (-11.3% [-21.4% to 0.1%]) compared with conventional therapy. The magnitude of reduction in left and right ventricular end diastolic volumes with frequent hemodialysis was accentuated among patients with residual urine output<100 ml/d (P value [interaction]=0.02). In the nocturnal trial, there were no significant changes in left or right ventricular volumes. The frequent dialysis interventions had no substantial effect on the ratio of left ventricular mass/left ventricular end diastolic volume in either trial.

CONCLUSIONS

Frequent in-center hemodialysis reduces left and right ventricular end systolic and diastolic ventricular volumes as well as left ventricular mass, but it does not affect left ventricular remodeling.

Quality of life of chronic kidney disease patients in developing countries

In the developing world, the emphasis of care for the patient with chronic kidney disease is, in general, focused on the basics of care and patient survival; attention is not primarily focused on quality of life assessments. However, this arena is beginning to attract more attention. It is important to determine if standardized instruments are valid in the developing world and which unique assessments need to be utilized in individual cultural settings.

Dialysate calcium concentration and mineral metabolism in long and long-frequent hemodialysis: a systematic review and meta-analysis for a Canadian Society of Nephrology clinical practice guideline

BACKGROUND

Patients treated with conventional hemodialysis (HD) develop disorders of mineral metabolism that are associated with increased morbidity and mortality. More frequent and longer HD has been associated with improvement in hyperphosphatemia that may improve outcomes.

STUDY DESIGN

Systematic review and meta-analysis to inform the clinical practice guideline on intensive dialysis for the Canadian Society of Nephrology.

SETTING & POPULATION

Adult patients receiving outpatient long (≥5.5 hours/session; 3-4 times per week) or long-frequent (≥5.5 hours/session, ≥5 sessions per week) HD.

SELECTION CRITERIA FOR STUDIES

We included clinical trials, cohort studies, case series, case reports, and systematic reviews.

INTERVENTIONS

Dialysate calcium concentration ≥1.5 mmol/L and/or phosphate additive.

OUTCOMES

Fragility fracture, peripheral arterial and coronary artery disease, calcific uremic arteriolopathy, mortality, intradialytic hypotension, parathyroidectomy, extraosseous calcification, markers of mineral metabolism, diet liberalization, phosphate-binder use, and muscle mass.

RESULTS

21 studies were identified: 2 randomized controlled trials, 2 reanalyses of data from the randomized controlled trials, and 17 observational studies. Dialysate calcium concentration ≥1.5 mmol/L for patients treated with long and long-frequent HD prevents an increase in parathyroid hormone levels and a decline in bone mineral density without causing harm. Both long and long-frequent HD were associated with a reduction in serum phosphate level of 0.42-0.45 mmol/L and a reduction in phosphate-binder use. There was no direct evidence to support the use of a dialysate phosphate additive.

LIMITATIONS

Almost all the available information is related to changes in laboratory values and surrogate outcomes.

CONCLUSIONS

Dialysate calcium concentration ≥1.5 mmol/L for most patients treated with long and long-frequent dialysis prevents an increase in parathyroid hormone levels and decline in bone mineral density without increased risk of calcification. It seems prudent to add phosphate to the dialysate for patients with a low predialysis phosphate level or very low postdialysis phosphate level until more evidence becomes available.

Risk of vascular access complications with frequent hemodialysis

Frequent hemodialysis requires using the vascular access more often than with conventional hemodialysis, but whether this increases the risk for access-related complications is unknown. In two separate trials, we randomly assigned 245 patients to receive in-center daily hemodialysis (6 days per week) or conventional hemodialysis (3 days per week) and 87 patients to receive home nocturnal hemodialysis (6 nights per week) or conventional hemodialysis, for 12 months. The primary vascular access outcome was time to first access event (repair, loss, or access-related hospitalization). Secondary outcomes were time to all repairs and time to all losses. In the Daily Trial, 77 (31%) of 245 patients had a primary outcome event: 33 repairs and 15 losses in the daily group and 17 repairs, 11 losses, and 1 hospitalization in the conventional group. Overall, the risk for a first access event was 76% higher with daily hemodialysis than with conventional hemodialysis (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.11-2.79; P=0.017); among the 198 patients with an arteriovenous (AV) access at randomization, the risk was 90% higher with daily hemodialysis (HR, 1.90; 95% CI, 1.11-3.25; P=0.02). Daily hemodialysis patients had significantly more total AV access repairs than conventional hemodialysis patients (P=0.011), with 55% of all repairs involving thrombectomy or surgical revision. Losses of AV access did not differ between groups (P=0.58). We observed similar trends in the Nocturnal Trial, although the results were not statistically significant. In conclusion, frequent hemodialysis increases the risk of vascular access complications. The nature of the AV access repairs suggests that this risk likely results from increased hemodialysis frequency rather than heightened surveillance.

Impact of frequent hemodialysis on anemia management: results from the Frequent Hemodialysis Network (FHN) Trials

BACKGROUND

The extent to which anemia management is facilitated by more frequent hemodialysis (HD) is controversial. We hypothesized as a preselected outcome that patients receiving HD six times (6×) compared with three times (3×) per week would require lower doses of erythropoietin-stimulating agents (ESA) and/or achieve higher blood hemoglobin (Hb) concentrations.

METHODS

Subjects enrolled in the Frequent Hemodialysis Network (FHN) daily and nocturnal trials were studied. As the primary outcome for anemia, the dose of ESAs was recorded at 4-month intervals and the monthly dose of intravenous iron (IV Fe) was reported. Serum iron, transferrin saturation and ferritin were measured at baseline and then at 4-month intervals, whereas Hb concentration was measured monthly.

RESULTS

There was no significant treatment effect in the 6× versus 3× treatment groups on logESA dose or the ratio of log of ESA dose to Hb concentration in either trial. In the daily trial, Hb concentrations increased significantly in the 6× versus 3× group, at Month 12 compared with baseline (0.3 g/dL; 95% CI: 0.05-0.58, P<0.021), but both groups had Hb concentrations in the usual target range. In the daily trial, the weekly logESA dose and the logESA dose to Hb concentration ratio tended to decline more in the 6× versus 3× group. This trend was not observed in the nocturnal trial. IV Fe doses were significantly lower in the 6× compared with the 3× group by Month 12 in the nocturnal trial, but not different in the daily trial.

CONCLUSIONS

In the FHN Daily and Nocturnal Trials, more frequent HD did not have a significant or clinically important effect on anemia management.

Effect of frequent hemodialysis on residual kidney function

Frequent hemodialysis can alter volume status, blood pressure, and the concentration of osmotically active solutes, each of which might affect residual kidney function (RKF). In the Frequent Hemodialysis Network Daily and Nocturnal Trials, we examined the effects of assignment to six compared with three-times-per-week hemodialysis on follow-up RKF. In both trials, baseline RKF was inversely correlated with number of years since onset of ESRD. In the Nocturnal Trial, 63 participants had non-zero RKF at baseline (mean urine volume 0.76 liter/day, urea clearance 2.3 ml/min, and creatinine clearance 4.7 ml/min). In those assigned to frequent nocturnal dialysis, these indices were all significantly lower at month 4 and were mostly so at month 12 compared with controls. In the frequent dialysis group, urine volume had declined to zero in 52% and 67% of patients at months 4 and 12, respectively, compared with 18% and 36% in controls. In the Daily Trial, 83 patients had non-zero RKF at baseline (mean urine volume 0.43 liter/day, urea clearance 1.2 ml/min, and creatinine clearance 2.7 ml/min). Here, treatment assignment did not significantly influence follow-up levels of the measured indices, although the range in baseline RKF was narrower, potentially limiting power to detect differences. Thus, frequent nocturnal hemodialysis appears to promote a more rapid loss of RKF, the mechanism of which remains to be determined. Whether RKF also declines with frequent daily treatment could not be determined.

Effects of 6-times-weekly versus 3-times-weekly hemodialysis on depressive symptoms and self-reported mental health: Frequent Hemodialysis Network (FHN) Trials

BACKGROUND

Patients undergoing maintenance hemodialysis frequently exhibit poor mental health. We studied the effects of frequent in-center and nocturnal hemodialysis on depressive symptoms and self-reported mental health.

STUDY DESIGN

1-year randomized controlled clinical trials.

SETTING & PARTICIPANTS

Hemodialysis centers in the United States and Canada. 332 patients were randomly assigned to frequent (6-times-weekly) compared with conventional (3-times-weekly) hemodialysis in the Frequent Hemodialysis Network (FHN) Daily (n = 245) and Nocturnal (n = 87) Trials.

INTERVENTION

The Daily Trial was a trial of frequent (6-times-weekly) compared with conventional (3-times-weekly) in-center hemodialysis. The Nocturnal Trial assigned patients to either frequent nocturnal (6-times-weekly) hemodialysis or conventional (3-times-weekly) hemodialysis.

OUTCOMES

Self-reported depressive symptoms and mental health.

MEASUREMENTS

Beck Depression Inventory and the mental health composite score and emotional subscale of the RAND 36-Item Health Survey at baseline and 4 and 12 months. The mental health composite score is derived by summarizing these domains of the RAND 36-Item Health Survey: emotional, role emotional, energy/fatigue, and social functioning scales.

RESULTS

In the Daily Trial, participants randomly assigned to frequent compared with conventional in-center hemodialysis showed no significant change over 12 months in adjusted mean Beck Depression Inventory score (-1.9 ± 0.7 vs -0.6 ± 0.7; P = 0.2), but experienced clinically significant improvements in adjusted mean mental health composite (3.7 ± 0.9 vs 0.2 ± 1.0; P = 0.007) and emotional subscale (5.2 ± 1.6 vs -0.3 ± 1.7; P = 0.01) scores. In the Nocturnal Trial, there were no significant changes in the same metrics in participants randomly assigned to nocturnal compared with conventional hemodialysis.

LIMITATIONS

Trial interventions were not blinded.

CONCLUSIONS

Frequent in-center hemodialysis, as compared with conventional in-center hemodialysis, improved self-reported general mental health. Changes in self-reported depressive symptoms were not statistically significant. We were unable to conclude whether nocturnal hemodialysis yielded similar effects.