Nutrient intake during peritoneal dialysis at the Prince of Wales Hospital in Hong Kong

Blood Levels of Endocannabinoids, Oxylipins, and Metabolites Are Altered in Hemodialysis Patients

Hemodialysis patients (HDPs) have higher blood pressure, higher levels of inflammation, a higher risk of cardiovascular disease, and unusually low plasma n-3 polyunsaturated fatty acid (PUFA) levels compared to healthy subjects. The objective of our investigation was to examine the levels of endocannabinoids (eCBs) and oxylipins (OxLs) in female HDPs compared to healthy matched female controls, with the underlying hypothesis that differences in specific PUFA levels in hemodialysis patients would result in changes in eCBs and OxLs. Plasma phospholipid fatty acids were analyzed by gas chromatography. Plasma was extracted and analyzed using ultra-performance liquid chromatography followed by electrospray ionization and tandem MS for eCBs and OxLs. The global untargeted metabolite profiling of plasma was performed by GCTOF MS. Compared to the controls, HDPs showed lower levels of plasma EPA and the associated OxL metabolites 5- and 12-HEPE, 14,15-DiHETE, as well as DHA derived 19(20)-EpDPE. Meanwhile, no changes in arachidonylethanolamide or 2-arachidonylglycerol in the open circulation were detected. Higher levels of multiple N-acylethanolamides, monoacylglycerols, biomarkers of progressive kidney disease, the nitric oxide metabolism-linked citrulline, and the uremic toxins kynurenine and creatine were observed in HDP. These metabolic differences in cCBs and OxLs help explain the severe inflammatory and cardiovascular disease manifested by HDPs, and they should be explored in future studies.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

Dietary Fiber Intake, Myocardial Injury, and Major Adverse Cardiovascular Events Among End-Stage Kidney Disease Patients: A Prospective Cohort Study

Introduction

Dialysis patients are frequently advised to restrict fruit and vegetable intake due to their high potassium content. This study aimed to evaluate the association between dietary fiber intake and major adverse cardiovascular events (MACE) among dialysis patients.

Methods

A total of 219 prevalent dialysis patients were prospectively recruited from a major university teaching hospital and regional dialysis center in Hong Kong. Dietary fiber intake estimated using a 7-day locally validated food frequency questionnaire was examined in relation to a primary composite outcome of MACE over a follow-up period of 4 years.

Results

A total of 127 patients were complicated with 1 or more MACE. In the multivariable Cox regression analysis, every 1 g higher fiber intake, and every 1 g/d per 1000 kcal higher fiber intake density were associated with an 11% (95% confidence interval [CI]: 0.81-0.97) and a 13% lower risk of MACE (95% CI: 0.77-0.99), respectively, independent of clinical, demographic, biochemical, hemodynamic, adequacy parameters, dietary protein, energy intake, inflammatory, and cardiac markers. Patients in the lower tertile of fiber intake density showed an increased hazard for MACE (adjusted hazard ratio: 1.78; 95% CI: 1.13-2.80) than those in the upper tertile.

Conclusion

Higher fiber intake and higher fiber intake density may be associated with less inflammation, less myocardial hypertrophy, injury, and lower risk of MACE in dialysis patients. These data form an important basis for a randomized controlled trial to examine fiber supplementation on cardiovascular outcomes in the dialysis population.

Association Between Comprehensive Nutritional Scoring System (CNSS) and Outcomes of Continuous Ambulatory Peritoneal Dialysis Patients

BACKGROUND/AIMS

The presence of protein-energy wasting (PEW) among dialysis patients is a crucial risk factor for outcomes. The complicated pathogenesis of PEW makes it difficult to assess and treat. This single-center retrospective study focuses on the association between nutritional markers and the outcomes of continuous ambulatory peritoneal dialysis(CAPD) patients, aiming to establish a practical comprehensive nutritional scoring system for CAPD patients.

METHODS

924 patients who initiated peritoneal dialysis in our center from January 1st,2005 to December 31st,2015 were enrolled. Comprehensive nutritional scoring system(CNSS) was based on items including SGA, BMI, ALB, TC, MAC and TSF. We divide patients into 3 groups according to their CNSS score. Outcomes including mortality, hospitalization days and hospitalization frequency were compared between 3 grades.

RESULTS

The CNSS grade correlated significantly with hospitalization days (P<0.05). Both categorized CNSS grade (HR:0.56; 95% CI:0.41-0.78; P = 0.001) and continuous CNSS score (HR:0.87; 95% CI: 0.80-0.94; P = 0.001) independently protect PD patients from all-cause mortality.

CONCLUSION

CNSS provides an integrated scoring system with significant associations with hospitalization and mortality in PD patients. The CNSS grade differentiates patients with malnutritional risk and independently predicts high risk of morbidity and mortality.

An integrative review of the methodology and findings regarding dietary adherence in end stage kidney disease

BACKGROUND

Dietary modification is an important component of the management of end stage kidney disease (ESKD). The diet for ESKD involves modifying energy and protein intake, and altering sodium, phosphate, potassium and fluid intake. There have been no comprehensive reviews to date on this topic. The aims of this integrative review were to (i) describe the methods used to measure dietary adherence (ii) determine the rate of dietary adherence and (iii) describe factors associated with dietary adherence in ESKD.

METHODS

The Web of Science and Scopus databases were searched using the search terms 'adherence' and 'end stage kidney disease'. Of the 787 potentially eligible papers retrieved, 60 papers of 24,743 patients were included in this review. Of these papers, 44 reported the rate of dietary adherence and 44 papers described factors associated with adherence.

RESULTS

Most of the evidence regarding dietary adherence is derived from studies of hemodialysis patients (72% of patients). The most common method of measuring dietary adherence in ESKD was subjective techniques (e.g. food diaries or adherence questionnaires). This was followed by indirect methods (e.g. serum potassium, phosphate or interdialytic weight gain). The weighted mean adherence rate to ESKD dietary recommendations was 31.5% and 68.5% for fluid recommendations. Adherence to protein, sodium, phosphate, and potassium recommendations were highly variable due to differences in measurement methods used, and were often derived from a limited evidence base. Socioeconomic status, age, social support and self-efficacy were associated with dietary adherence. However, factors such as taste, the impact of the diet on social eating occasions; and dietetic staffing also appear to play a role in dietary adherence.

CONCLUSION

Dietary adherence rates in people with ESKD are suboptimal. Further research is required on dietary adherence in patients with ESKD from different social, educational, economic and ethnic groups. This research may identify other factors which may impact upon adherence, and could be used to inform the design of future strategies to improve dietary adherence. Future research that reports not just the rate of adherence to individual components of the nutrient prescription but also the overall quality of the diet would be useful.

APPETITE PREDICTS INTAKE AND NUTRITIONAL STATUS IN PATIENTS RECEIVING PERITONEAL DIALYSIS

BACKGROUND

Sub-optimal nutrition status is common amongst patients receiving peritoneal dialysis (PD) and leads to poor clinical outcome. This population experiences multi-factorial challenges to achieving optimal nutritional status, particularly driven by inadequate intake.

OBJECTIVES

The aim of this investigation was to identify factors associated with inadequate protein intake and sub-optimal nutritional status in patients undergoing PD.

DESIGN/PARTICIPANTS

This was a cross-sectional study of 67 adult patients receiving PD (mean age 59 ± 14 years; 57% male) within a single centre. Participants were consecutively recruited and interviewed by renal dietitians, collecting: Subjective Global Assessment (SGA); quality of life (using EQ-5D); dietary intake (via dietary interview); and appetite (using Appetite and Diet Assessment Tool). Participant demographics were obtained via survey or medical charts. Main outcome measures were inadequate dietary protein intake (<1.1 g/kg adjusted body weight/day) and malnutrition (as defined by SGA rating B or C).

RESULTS

Overall, 15 (22%) patients were malnourished and 29 (43%) had inadequate protein intake. Poor appetite (anorexia) was reported in 62% (18/29) of participants with inadequate protein malnourished patients reported anorexia versus 12 (23%) of the well-nourished patients (p = 0.0001).

CONCLUSION

Anorexia was a key risk factor for inadequate protein intake and malnutrition in patients undergoing PD. These findings highlight a need to closely monitor patients with appetite disturbances.

Phosphorus metabolism in peritoneal dialysis- and haemodialysis-treated patients

BACKGROUND

Phosphorus control is generally considered to be better in peritoneal dialysis (PD) patients as compared with haemodialysis (HD) patients. Predialysis phosphorus concentrations are misleading as a measure of phosphorus exposure in HD, as these neglect significant dialysis-related fluctuations.

METHODS

Parameters of mineral metabolism, including parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF-23), were determined in 79 HD and 61 PD patients. In PD, phosphorus levels were determined mid-morning. In HD, time-averaged phosphorus concentrations were modelled from measurements before and after the mid-week dialysis session. Weekly renal, dialytic and total phosphorus clearances as well as total mass removal were calculated from urine and dialysate collections.

RESULTS

Time-averaged serum phosphorus concentrations in HD (3.5 ± 1.0 mg/dL) were significantly lower than the mid-morning concentrations in PD (5.0 ± 1.4 mg/dL, P < 0.0001). In contrast, predialysis phosphorus concentrations (4.6 ± 1.4 mg/dL) were not different from PD. PTH and FGF-23 levels were significantly higher in PD. Despite higher residual renal function, total phosphorus clearance was significantly lower in PD (P < 0.0001). Total phosphorus mass removal, conversely, was significantly higher in PD (P < 0.05).

CONCLUSIONS

Our data suggest that the time-averaged phosphorus concentrations in patients treated with PD are higher as compared with patients treated with HD. Despite a better preserved renal function, total phosphorus clearance is lower in patients treated with PD. Additional studies are needed to confirm these findings in a population with a different demographic profile and dietary background and to define clinical implications.

Dietary phosphorus intake and distribution in Chinese peritoneal dialysis patients with and without hyperphosphatemia

BACKGROUND

The present study was conducted to analyze the dietary phosphorus intake and distribution in different food categories in peritoneal dialysis (PD) patients, to evaluate the relationship between dietary phosphorus intake and hyperphosphatemia.

METHODS

It was a cross-sectional study, in which prevalent Chinese PD patients were instructed by dietitians to record 3-day diet diary. Dietary phosphorus and other nutrient contents were calculated using a food composition computer program. Renal and peritoneal phosphorus clearance (CPh) was estimated, and serum phosphorus, as well as other serological parameters, were measured at the same time.

RESULTS

93 PD patients [age 52.9 ± 13.0 years, PD duration 30.1 (8.0, 71.0) months] finished the 3-day diet diary. Hyperphosphatemic patients (serum phosphorus level 1.97 ± 0.28 mmol/l, n = 48) showed higher dietary phosphorus intake (771.6 ± 195.1 versus 620.8 ± 155.3 mg/day, p = 0.040) than those with normal serum phosphorus level (1.37 ± 0.21 mmol/l, n = 45), due to greater phosphorus intake from meat, snacks, beverage, food condiments and additives. Significantly lower dietary phosphorus intake (605.6 ± 122.5 mg/day) and phosphorus to protein ratio (12.7 ± 1.4 mg/g) were observed in patients with anuria who maintained serum phosphorus within normal range. Multivariate linear regression analysis indicated normalized phosphorus intake, renal CPh and dietary protein intake were independently associated with serum phosphorus level.

CONCLUSION

High dietary phosphorus intake is associated with elevated serum phosphorus level in PD patients. The study suggests that PD patients, particularly those with anuria, shall limit the intake of meat, snacks, beverage, food condiments and additives to reduce dietary phosphorus ingestion.

British Dietetic Association evidence-based guidelines for the protein requirements of adults undergoing maintenance haemodialysis or peritoneal dialysis

BACKGROUND

Existing nutritional guidelines suggest that protein requirements of adults with stage five chronic kidney disease undergoing haemodialysis (HD) or peritoneal dialysis (PD) are increased as a result of protein losses during dialysis. The present review aimed to update previous guidance and develop evidence-based practice guidelines on the protein requirements of adults undergoing maintenance dialysis.

METHODS

Following a PICO approach (Participants or Population, Intervention or Exposure, Comparison and Outcome), four research questions were formulated to investigate the total protein requirement and protein quality required by adults undergoing HD and PD. A comprehensive, systematic review was undertaken using the databases Medline, EMBASE and the Cochrane Library from 2005 to September 2009 for HD studies and from 1997 to September 2009 for PD studies.

RESULTS

The literature search yielded 2931 studies, which were assessed for inclusion. Following appraisal, 19 studies in HD and 18 studies in PD met the inclusion criteria and were systematically reviewed. Limited good quality evidence supports the recommendations that: (i) adults undergoing maintenance HD require a minimum protein intake of 1.1 g kg(-1) ideal body weight (IBW) per day; and (ii) adults undergoing maintenance PD require a minimum protein intake of 1.0-1.2 kg(-1) IBW per day, in conjunction with an adequate energy intake. There were no studies that addressed the quality of protein for either HD or PD.

CONCLUSIONS

Evidence suggests that nutritional status may be maintained with lower protein intakes than previously recommended. However, the evidence base is limited and further randomised controlled trials are required to establish the optimal protein intake for dialysis patients.

Nutrition in patients on peritoneal dialysis

Protein-energy wasting (PEW) is prevalent among patients on dialysis and has emerged as an important risk factor for morbidity and mortality in these patients. Numerous factors, including inflammation, inadequate dialysis, insufficient nutrient intake, loss of protein during dialysis, chronic acidosis, hypercatabolic illness and comorbid conditions, are involved in the development of PEW. The causes and clinical features of PEW in patients on peritoneal dialysis and hemodialysis are comparable; assessment of the factors that lead to PEW in patients receiving peritoneal dialysis is important to ensure that PEW is managed correctly in these patients. For the past 20 years, much progress has been made in the prevention and treatment of PEW. However, the results of most nutritional intervention studies are inconclusive. In addition, the multifactorial and complicated pathogenesis of PEW makes it difficult to assess and treat. This Review summarizes the nutritional issues regarding the causes, assessment and treatment of PEW, with a focus on patients receiving peritoneal dialysis. In addition, an in-depth overview of the results of nutritional intervention studies is provided.

Dietary intake in hemodialysis patients does not reflect a heart healthy diet

OBJECTIVE

Cardiovascular disease is highly prevalent and has a major effect on morbidity and mortality in patients undergoing maintenance hemodialysis (MHD). Dietary factors that may contribute to cardiovascular disease have not been well studied in this population. We hypothesize that dietary intake in this population does not meet the guidelines for cardiovascular risk reduction.

DESIGN

A cross-sectional study was completed using the validated "Block Dialysis 1 Food Frequency Questionnaire" to assess dietary intake of MHD patients.

SETTING AND PATIENTS

A total of 70 patients undergoing MHD at our outpatient dialysis center completed the questionnaire under the supervision of a trained dietitian. The population consisted of 38 men and 32 women.

MAIN OUTCOME MEASURE

Dietary intake was the main outcome measure, with a focus on calories, soluble fiber, saturated fatty acid (SFA), unsaturated fatty acid intake (UFA), and protein.

RESULTS

The mean fiber intake was 10.77 (±5.87) g/day, and only 2 of 71 (2.9%) were in compliance with the recommended daily intake of >25 g/day. As percentage of total calories, of the 70 patients, 5 (7.1%) had a fat intake of <30%, 22 (31.4%) had SFA intake of <10%, 64 (91.4%) had a UFA of ≤30%, 22 (31.4%) had a protein-based diet of ≥15%, and 66 (94.3%) had a carbohydrate diet of <60%.

CONCLUSIONS

Most patients did not meet the dietary guidelines for reducing the risk of cardiovascular disease. Substituting UFA or soluble fiber for SFA improves low density lipoprotein (LDL) cholesterol levels without negative effects on other lipid parameters.

Bicarbonate-Based Peritoneal Dialysis Solution has Less Effect on Ingestive Behavior than Lactate-Based Peritoneal Dialysis Solution

Objective

The anorexia seen in peritoneal dialysis (PD) patients may be due partially to factors of dialysis solutions, such as pH and buffering agent. We tested the effects of different PD solutions in an experimental rat model for appetite.

Design

The intraoral intake of a sucrose solution from an implanted intraoral cannula in freely moving male Wistar rats was used to evaluate appetite at 30 minutes and 120 minutes after intraperitoneal (IP) infusion of bicarbonate (25 mmol/L)/lactate (15 mmol/L)-based PD solution (P) and conventional lactate (40 mmol/L)-based PD solution (D) with different concentrations of glucose. We also tested different buffer solutions containing lactate and bicarbonate with different pH but with no glucose.

Results

The IP infusion as such and the 30 mL volume did not inhibit appetite; however, appetite was significantly less inhibited by P than by D in the 1.36%, 2.27%, and 3.86% solutions ( p < 0.05). Furthermore, intraoral intake was significantly higher in rats receiving IP solution with bicarbonate buffer (pH 7.4) than with lactate buffer ( p < 0.05), whereas there was no significant difference in intraoral intake for lactate with pH 5.5, pH 6.6, or pH 7.4.

Conclusions

The bicarbonate/lactate solution inhibited appetite less than the lactate solution; this was due partially to the use of bicarbonate. The results show possible benefit on appetite of reducing the lactate concentration in PD solutions.

Impact of Stratification of Comorbidities on Nutrition Indices and Survival in Patients on Continuous Ambulatory Peritoneal Dialysis

Background

Case-mix comorbidities and malnutrition influence outcome in continuous ambulatory peritoneal dialysis (CAPD) patients. In the present study, we analyzed the influence of stratified comorbidities on nutrition indices and survival in CAPD patients.

Patients and Methods

We categorized 373 CAPD patients (197 with and 176 without diabetes) into three risk groups: low—age under 70 years and no comorbid illness; medium—age 70 – 80 years, or any age with 1 comorbid illness, or age under 70 years with diabetes; high—age over 80 years, or any age with 2 comorbid illnesses. We then compared nutrition indices and malnutrition by subjective global assessment (SGA) between the three groups. Survival was compared using Kaplan–Meier survival analysis.

Results

Mean daily calorie and protein intakes in the low-risk group (21 ± 6.7 Kcal/kg, 0.85 ± 0.28 g/kg) were significantly higher than in the medium- (17.6 ± 5.2 Kcal/kg, 0.79 ± 0.25 g/kg) and high-risk (17.5 ± 6.1 Kcal/kg, 0.78 ± 0.26 g/kg) groups ( p = 0.001 and p = 0.04 respectively). Relative risk (RR) of malnutrition was less in the low-risk group (103/147, 70.06%) than in the medium-risk group [135/162, 83.3%; RR: 2.0; 95% confidence interval (CI): 2.1 to 3.4; p = 0.01] or the high-risk group (54/64, 84.4%; RR: 2.3; 95% CI: 2.1 to 4.9; p = 0.03). Mean survivals of patients in the low-, medium-, and high-risk groups were 51 patient–months (95% CI: 45.6 to 56.4 patient–months), 43.3 patient–months (95% CI: 37.8 to 48.7 patient–months), and 29.7 patient–months (95% CI: 23 to 36.4 patient–months) respectively (log-rank: 35.9 patient–months; p = 0.001). The 1-, 2-, 3-, 4-, and 5-year patient survivals in the low-, medium-, and high-risk groups were 96%, 87%, 79%, 65%, and 56%; 89%, 67%, 54%, 43%, and 34%; and 76%, 48%, 31%, 30%, and 30% respectively.

Conclusions

Intake of calories and protein was significantly lower in the medium-risk and high-risk groups than in the low-risk group. Survival was significantly better in low-risk patients than in medium- and high-risk patients.