Daily protein intake and survival in patients on peritoneal dialysis

Estimating Dietary Protein and Sodium Intake with Sodium Removal in Peritoneal Dialysis Patients

An increase in dietary protein intake (DPI) carries a risk with respect to increased sodium intake, which further leads to the development of cardiovascular morbidity in peritoneal dialysis (PD) patients. Dialytic (DSR) and urinary sodium removal (USR) are potential indicators of sodium intake. In this single-center cross-sectional study with 60 prevalent PD patients, we analyze the correlation of DPI with sodium intake and the association between residual renal function (RRF) and comorbidity grade, expressed as the Davies score with sodium removal and protein metabolism indices such as normalized protein catabolic rate (nPCR) and lean body mass (LBM). The value of RRF < 2 mL/min/1.73 m2 is significantly associated with lower USR (p = 0.000) and lower %LBM (p < 0.001). The greatest USR is detected in patients with low Davies comorbidity grade (p = 0.018). Compared to patients with DPI < 0.8 g/kg/day, patients with DPI > 0.8 g/kg/day have a greater sodium intake (3.69 ± 0.71 vs. 2.94 ± 0.86; p < 0.018) and a greater nPCR (p < 0.001). Protein intake is significantly correlated with sodium intake (p = 0.041), but not with total sodium removal (TSR). A strong correlation is observed between sodium intake and TSR (p = 0.000), although single TSR values are not the same as the corresponding sodium intake values. An increasing protein intake implies the necessity to determine both sodium intake and sodium removal. Preservation of RRF has a beneficial role not just in sodium removal, but also in the increase of LBM.

Dietary Patterns, Dietary Adequacy and Nutrient Intake in Adults Commencing Peritoneal Dialysis: Outcomes from a Longitudinal Cohort Study

(1) Background: Optimal dietary intake is integral to good health in people receiving peritoneal dialysis (PD). We investigated how dietary patterns, dietary adequacy and nutrient intake may change over time in people commencing PD. (2) Methods: Participants were attending the PD training unit for the commencement of peritoneal dialysis, aged ≥18 years and willing to complete food records. Misreporters were excluded from the analysis. Dietary intake was compared at PD commencement and at 12 months. Intake was also compared to reference standards. Dietary patterns were derived using principal component analysis. (3) Results: There were no significant changes between baseline and 12 months for grains, fruit, vegetables and meat. Dairy and added sugar intake was significantly lower (p = 0.01). The intake of energy and protein was adequate and did not change. There was a significant reduction in dietary phosphorus and calcium, and increased vitamin C intake. Three dietary patterns were identified: the 'Bread and Cereal' pattern; 'Milk and Potatoes' pattern; and the 'Semi Vegetarian' pattern. (4) Conclusions: In this longitudinal cohort study, the diet quality was suboptimal and there were limited changes in intake after the commencement of PD. Further exploration of how dietary patterns may impact outcomes and quality of life is warranted.

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial

OBJECTIVE

Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis.

DESIGN

Pilot, prospective, open-label randomised controlled trial.

SETTING

Peking University First Hospital, China.

PARTICIPANTS

Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020.

INTERVENTIONS

Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis.

RESULTS

Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon.

CONCLUSIONS

A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

Longitudinal association between dietary protein intake and survival in peritoneal dialysis patients

BACKGROUND

Decreased dietary protein intake (DPI) may lead to protein-energy malnutrition and may be associated with increased mortality risk. We hypothesized that longitudinal changes in dietary protein intake have independent associations with survival in peritoneal dialysis (PD) patients.

METHODS

668 stable PD patients were selected in the study from January 2006 to January 2018 and were followed up until December 2019. Their three-day dietary records were collected at the baseline (the sixth month after PD) and thereafter every 3 months for two and a half years. The latent class mixed models (LCMM) were used to identify subgroups of PD patients with similar longitudinal trajectories of DPI. The relation between DPI (baseline and longitudinal data) and survival was examined using Cox model to estimate death hazard ratios. Meanwhile, different formulae were used to assess nitrogen balance.

RESULTS

The results showed that baseline DPI ≤ 0.60g/kg/day was associated with the worst outcome in PD patients. Patients with DPI 0.80-0.99g/kg/day and DPI ≥ 1.0g/kg/day both presented positive nitrogen balance; patients with DPI 0.61-0.79g/kg/day presented obviously negative nitrogen balance. Longitudinal association between time-dependent DPI and survival was found in PD patients. The consistently low DPI' (0.61-0.79g/kg/d) group was correlated with increased death risk as compared with the 'consistently median DPI' group (0.80-0.99g/kg/d, HR = 1.59, p = 0.008), whereas there was no difference in survival between 'consistently median DPI' group and 'high-level DPI' group (≥1.0 g/kg/d, p > 0.05).

CONCLUSION

Our study revealed that DPI ≥ 0.8 g/kg/day was beneficial to the long-term outcome for the PD population.

A 12-week personalised physical activity and dietary protein intervention for older adults undergoing peritoneal dialysis: A feasibility study

This single-arm observational study explored the feasibility and efficacy of a 12-week personalised physical activity and dietary protein intervention programme for older adults undergoing peritoneal dialysis. Older adults undergoing peritoneal dialysis received eight individualised nutrition and physical activity advice sessions provided by trained nurses. Protein intake and physical activity were regarded as primary outcomes. All data were collected at baseline and at week 12. The enrolment rate was 78.4%. Twenty-nine patients participated in the study. Of these, 86.2% (25/29) completed the intervention. There was a significant increase in protein intake (t = -4.453, P< 0.001) and physical activity levels (Z = -2.929, P = 0.004). Of the participants, 56.0% achieved the targeted protein goal, and 41.4% met the physical activity goal. The timed up-and-go performance (t = 4.135, P = 0.001) increased after intervention. Trained nurses can successfully implement personalised diet and physical activity advice, and achieve promising patient outcomes.

WeChat-Based Comprehensive Education on Egg White Protein Intake for Patients Undergoing Peritoneal Dialysis: A Combined Prospective and Retrospective Study

Protein malnutrition is a well-described complication of peritoneal dialysis (PD), a standard mode of treatment for end-stage renal disease (ESRD), and contributes to morbidity, treatment failure, and mortality. To assess the usefulness of WeChat-based education for ensuring optimal protein intake through the consumption of egg white protein, 140 young and middle-aged patients undergoing PD are assigned to either the intervention group or the control group. The results show that reinforcing comprehensive PD education using WeChat can improve nutritional parameters, clinical parameters, and quality of life.

Sleep Quality After Intradialytic Oral Nutrition: A New Benefit of This Anabolic Strategy? A Pilot Study

Background

Since disturbances of appetite and sleep are closely related and both affect metabolic disorders, it would be expected that a renal specific oral nutritional supplement (RS-ONS) that covers the energy the patient does not consume on the HD day, could contribute to improve the nutritional status and body composition, as well as sleep quality. There is still scarce information related to this topic.

Aim

To evaluate the effect of the use of intra-dialytic RS-ONS vs. RS-ONS at home on sleep quality, nutritional status, and body composition in patients on HD.

Methods

Adult patients &lt; 65 years, with ≥3 months on HD were invited to participate in an open randomized pilot study (ISRCTN 33897). Patients were randomized to a dialysis-specific high-protein supplement provided during the HD session (Intradialytic oral nutrition [ION]) or at home (control), during non-HD days (thrice weekly, for both) 12 weeks. The primary outcome was sleep quality defined by the Pittsburgh Sleep Quality Index (PSQI) score. Nutritional assessment included Malnutrition Inflammation Score (MIS), bioelectrical impedance analysis, anthropometry, 3-day food records, and routine blood chemistries.

Results

A total of 23 patients completed the study. Age was median 35 (range 24–48 years), 42% were women. At baseline, the PSQI score was median 4 (range 2–7), and MIS showed a median of 6 (range 5–8); there were no baseline differences between groups. After intervention, both groups improved their MIS scores and similarly when we analyzed the whole cohort (pre- vs. post-intervention P &lt; 0.01). Patients in the ION group improved the overall PSQI score to median 3 (2–5), and assessment of sleep duration and sleep disturbances (pre- vs. post-intervention P &lt; 0.05), with a trend toward an effect difference compared to patients consuming the supplement at home (P for treatment-effect across arms 0.07 for PSQI score and 0.05 for sleep latency).

Conclusion

Oral supplementation improved nutritional status in the whole cohort, but only ION improved the PSQI score. More studies are needed to explore the nutritional strategies that influence the relationship between sleep and nutritional status in HD patients.

Development and Validation of a Prediction Model for the Cure of Peritoneal Dialysis-Associated Peritonitis: A Multicenter Observational Study

Aim

Peritoneal dialysis (PD)-associated peritonitis (PDAP) is a severe complication of PD. It is an important issue about whether it can be cured. At present, there is no available prediction model for peritonitis cure. Therefore, this study aimed to develop and validate a prediction model for peritonitis cure in patients with PDAP.

Methods

Patients with PD who developed PDAP from four dialysis centers in Northeast China were followed up. According to the region of PD, data were divided into training and validation datasets. Initially, a nomogram for peritonitis cure was established based on the training dataset. Later, the nomogram performance was assessed by discrimination (C-statistic), calibration, and decision curves.

Results

Totally, 1,011 episodes of peritonitis were included in the final analysis containing 765 in the training dataset and 246 in the validation dataset. During the follow-up period, peritonitis cure was reported in 615 cases from the training dataset and 198 from the validation dataset. Predictors incorporated in the final nomogram included PD duration, serum albumin, antibiotics prior to admission, white cell count in peritoneal dialysate on day 5 (/μl) ≥ 100/μl, and type of causative organisms. The C-statistic values were 0.756 (95% CI: 0.713–0.799) in the training dataset and 0.756 (95% CI: 0.681–0.831) in the validation dataset. The nomogram exhibited favorable performance in terms of calibration in both the training and validation datasets.

Conclusion

This study develops a practical and convenient nomogram for the prediction of peritonitis cure in patients with PDAP, which assists in clinical decision-making.

The estimation of protein equivalents of total nitrogen in Chinese CAPD patients: an explanatory study

Objective

The protein equivalent of total nitrogen appearance (PNA) formula, based on the urea nitrogen appearance (UNA), is popularly used by stable continuous ambulatory peritoneal dialysis (CAPD) patients to estimate dietary daily protein intake (DPI). However, we found that the estimated DPI was higher than that directly evaluated from the dietary records of most of our CAPD patients. Therefore, in the present study, we tried to determine possible bias in PNA estimation by UNA with a nitrogen balance study of our CAPD patients.

Methods

Thirty-one CAPD patients with stable clinical conditions were included. Their 3-day dietary records were reviewed by a dedicated dietitian to calculate their energy, protein, and nitrogen intake (NI). The nitrogen removal (NR) from urine and dialysate was measured by the Kjeldahl technique. Then, we calculated the proportion of urea nitrogen appearance (UNA) in total nitrogen appearance (TNA) and analyzed the possible factors that could affect this proportion.

Results

Among these patients, 17 males and 14 females, the mean age was 64.19 ± 12.42, and the dialysate drainage volume was 6700 (2540) ml/day. The percentage of UNA in TNA was 63.22 ± 6.66%. Compared with the other classic nitrogen balance studies in the CAPD population, the protein nitrogen and other nonurea nitrogen losses in this study were all lower. Based on these 31 nitrogen balance studies, we proposed a pair of new equations to estimate PNA by UNA. (1) PNA = 9.3 + 7.73 UNA; (2) PNA = PNPNA + TPL = 6.7 + 7.28 UNA + TPL.

Conclusion

Our study suggested that the PNA formula generated from previous European studies overestimated DPI in our CAPD patients.

Trimethylamine-N-oxide (TMAO) and clinical outcomes in patients with end-stage kidney disease receiving peritoneal dialysis

BACKGROUND

Trimethylamine-N-oxide (TMAO) is a gut bacteria-derived metabolite of l-carnitine and choline. A high concentration of TMAO has been proven to relate to cardiovascular disease (CVD), all-cause mortality and chronic kidney disease progression. We aimed to investigate the relation between the value of serum TMAO and outcomes for peritoneal dialysis (PD) patients.

METHODS

This is a prospective cohort study with data retrospectively analysed. All incident PD patients were enrolled and followed up. Log-rank test, competing risk survival analysis and COX regression were performed to test the effect of serum TMAO on developing first-episode peritonitis, all-cause and CVD mortality.

RESULTS

A wide distribution of serum TMAO concentration was observed in 513 PD patients, with a median level of 72.3 (43.7, 124.7) µmol/L. Patients with lower TMAO concentration were more likely to be without diabetes and hypertension. Patients with lower TMAO concentration showed better residual kidney function and solute clearance at baseline. Participants in the higher three TMAO quartiles showed an increased risk for first-episode peritonitis (p = 0.039). By competing risk survival analysis, after adjusting for age, sex, diabetes mellitus, CVD, body mass index, albumin, high-sensitive C-reactive protein, potassium, phosphorus, residual kidney function, normalised protein equivalent of total nitrogen appearance and calendar year of catheter implantation, patients in the higher three TMAO quartiles had a statistically or marginally higher risk for first-episode peritonitis compared with patients in the lowest quartile, with hazard ratio (HR) 1.65 (1.05, 2.58), 1.46 (0.92, 2.31) and 1.66 (1.05, 2.61), respectively. In the COX model, patients in the third quartile TMAO group had significantly higher CVD mortality risk compared with the lowest quartile group, as HR 2.27 (1.02, 5.05) after adjusting for various factors. As for all-cause mortality, TMAO did not show any associated effects.

CONCLUSIONS

Serum TMAO concentration is associated with the risk of first-episode peritonitis and CVD mortality in PD patients. No obvious association between serum TMAO and all-cause mortality was observed.

Nutritional predictors associated with malnutrition in continuous ambulatory peritoneal dialysis patients

BACKGROUND

Currently in China, out of the total dialysis population, approximately 20% represents continuous ambulatory peritoneal dialysis (CAPD) and almost half of CAPD patients was affected by malnutrition. This study aimed to investigate the association between nutritional predictors and malnutrition with 5.1 years of dialysis according to the subjective global assessment (SGA) in continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

A cross-sectional study was conducted from April 2013 to May 2018 and included 70 CAPD patients. The relationship between anthropometric and biochemical parameters with malnutrition was assessed by multiple logistic regression analysis.

RESULTS

The prevalence of malnutrition in CAPD patients was 52.9%. Our result revealed a 7.05-fold increased odds of malnutrition for patients with protein equivalent of total nitrogen appearance normalized to body weight (nPNA) < 1.0 g/kg per day (d) versus patients with normal nPNA (confidence interval (CI) 1.33-37.34; p < 0.05). Patients whose normalized protein catabolic rate (nPCR) was <1.2 g/(kg/d) had a significant positive association with malnutrition versus patients with normal nPCR (adjusted odds ratio (OR) 7.99; p < 0.05). Patients with dietary protein intake (DPI) < 1.0 g/(kg/d) had a higher likelihood of malnutrition than those with normal DPI (OR 12.73; p < 0.05). CAPD patients with upper arm circumference (UAC) < 23.2 cm had a high risk of malnutrition versus patients with normal UAC (OR 12.99; p < 0.05).

CONCLUSIONS

Our study suggested a close association between nPNA, DPI, nPCR, and UAC and malnutrition in CAPD patients. Further studies can be warranted the use of these variables as predictors and a malnutrition consequence among Chinese CAPD patients.

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.

Normalized Protein Catabolic Rate Is a Superior Nutritional Marker Associated With Dialysis Adequacy in Continuous Ambulatory Peritoneal Dialysis Patients

Introduction: Current knowledge of the relationship between normalized protein catabolic rate (nPCR) and dialysis adequacy is limited. Our study aimed to explore the potential relationship between nPCR and dialysis adequacy.

Methods: In this cross-sectional study, we analyzed the association of nPCR with peritoneal dialysis adequacy in 266 continuous ambulatory peritoneal dialysis (CAPD) patients (mean age 48.6 ± 13.1 years; 50.8% male). The patients were divided into two groups: a dialysis inadequacy group (total weekly Kt/V urea < 1.70) and a dialysis adequacy group (total weekly Kt/V urea≥1.70). We then analyzed the correlation between dialysis adequacy and the patients' primary cause of end-stage renal disease, nutritional and inflammatory markers, and biochemical parameters. Multivariable logistic regression analysis was also used to identify risk factors for inadequate dialysis.

Results: We observed a significantly higher level of nPCR (0.98 ± 0.22 vs. 0.79 ± 0.18 g/kg/day, p < 0.001) in the dialysis adequacy group, whereas we observed no significant differences among other nutritional markers such as albumin, prealbumin, and transferrin. Correlation analyses revealed that dialysis adequacy was positively associated with residual glomerular filtration rate (rGFR), hemoglobin, serum calcium, and body mass index (BMI), while dialysis adequacy was negatively associated with leak-protein, uric acid, high-sensitivity C-reactive protein, interleukin-6, and serum phosphorus. Furthermore, a logistic regression analysis revealed that gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² were independent risk factors for inadequate dialysis.

Conclusion: Nutritional status is closely associated with dialysis adequacy. Among common nutritional markers, nPCR may be superior for predicting CAPD dialysis adequacy. Gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² are independent risk factors for dialysis inadequacy in CAPD patients.

Exploring Metabolic Signature of Protein Energy Wasting in Hemodialysis Patients

End-stage renal disease patients undergoing maintenance hemodialysis (HD) are vulnerable to the protein energy wasting (PEW) syndrome. Identification and diagnosis of PEW relies on clinical processes of judgment dependent on fulfilling multiple criteria drawn from serum biochemistry, weight status, predictive muscle mass, dietary energy and protein intakes. Therefore, we sought to explore the biomarkers’ signature with plasma metabolites of PEW by using ¹H-nuclear magnetic resonance for an untargeted metabolomics approach in the HD population, to understand metabolic alteration of PEW. In this case-controlled study, a total of 53 patients undergoing chronic HD were identified having PEW based on established diagnostic criteria and were age- and sex-matched with non-PEW (n = 53) HD patients. Fasting predialysis plasma samples were analyzed. Partial least square discriminant analysis demonstrated a significant separation between groups for specific metabolic pattern alterations. Further quantitative analysis showed that the level of 3-hydroxybutyrate, acetate, arabinose, maltose, ribose, sucrose and tartrate were significantly increased whilst creatinine was significantly decreased (all p < 0.05) in PEW subjects. Pathway analysis indicated that PEW-related metabolites reflected perturbations in fatty acid mechanism and induction of glyoxylate and dicarboxylate pathway attributed to gluconeogenesis. These results provide preliminary data in understanding metabolic alteration of PEW and corresponding abnormal metabolites that could potentially serve as biomarkers of PEW.

Prescribing peritoneal dialysis and achieving good quality dialysis in low and low-middle income countries

The provision of long-term renal replacement therapies for patients with end-stage kidney disease (ESKD) in low and low-middle income countries (LLMICs) has been a pervasive challenge, impeded mainly by monetary constraints, limited health-care resources, and geographical and logistic difficulties. Even for patients who could initiate dialysis, discontinuation of dialysis treatment due to the lack of financial sustainability is a valid concern. While the delivery of high-quality dialysis should not be compromised in these settings, perpetuity on dialysis is of paramount consideration for these patients, with sustaining life being just as important as achieving clinical well-being. As intensification of peritoneal dialysis (PD) prescription comes with immense cost in these settings, the strategy for stretching affordability of dialysis involves optimizing the number of PD exchanges required or delaying the transition to a high PD dose of four bags per day of continuous ambulatory PD (CAPD) prescription. This can be accomplished through the use of low-cost adjunctive treatment, by preserving residual kidney function and adopting incremental PD. The use of expensive, complex, or inaccessible monitoring tools for peritoneal membrane function and dialysis clearance could be replaced by clinical assessment and widely available biochemical indicators, which will significantly reduce the investigation costs, with consequent savings that could allow for lengthening the duration of PD therapy. Finally, it is important for each PD program in LLMICs to monitor these outcome indicators, to ensure the consistent delivery of acceptable quality of PD to their patients.

The effects of oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: study protocol for a randomized controlled clinical trial

BACKGROUND

Vitamin D deficiency has been shown to be closely associated with peritoneal dialysis (PD)-related peritonitis. The aim of this study is to examine the feasibility of conducting a large, powered randomized controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis in patients who have already experienced an episode of peritonitis.

METHODS

This prospective, open-label randomized controlled pilot trial with blinded end-points aims to determine the feasibility of oral vitamin D supplementation and to explore its effects on the risk of subsequent PD-related peritonitis among PD patients who have recovered from a recent episode of peritonitis. Eligible patients will be randomized 1:1 to either oral vitamin D supplementation (2000 IU per day; intervention group) or no vitamin D supplementation (control group) in addition to usual care according to International Society for Peritoneal Dialysis guidelines. The sample size will be 30 patients for both groups. All participants will be followed for 12 months. The primary outcome is the assessment of feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25-hydroxyvitamin D level during follow-up) for a large, powered randomized controlled trial to determine the effects of vitamin D on the risk of PD-related peritonitis in the future. Secondary outcomes include time to peritonitis occurrence, recovery of peritonitis, peritonitis-related transition to hemodialysis, and peritonitis-related death (defined as death within 30 days of peritonitis onset).

DISCUSSION

This is the first randomized controlled trail investigating the effects of vitamin D supplementation on the risk of subsequent PD-related peritonitis among patients on PD. The findings for this pilot study will determine the feasibility of conducting a full-scale randomized controlled trail, which may provide a new strategy for preventing PD-related peritonitis among PD patients.

TRIAL REGISTRATION

Clinicaltrails.gov, NCT03264625. Registered on 29 August 2017.

Education and Protein Supplementation Improve Nutritional Biomarkers among Hypoalbuminemic Peritoneal Dialysis Patients: A Quasi-Experimental Design

Protein-energy wasting is prevalent in peritoneal dialysis patients, which causes a heavy burden for individuals and healthcare systems. We aimed to investigate the effect of nutritional education, and/or protein supplementation on nutritional biomarkers in hypoalbuminemic peritoneal dialysis patients. A quasi-experimental study was conducted in two dialysis centers at Taipei Tzu Chi Hospital and Shin Kong Wu Ho-Su Memorial Hospital. Patients were allocated in three groups including control (n = 12), milk protein (n = 21) and soy protein (n = 20). All patients received dietary guidelines from dietitians and completed 3-day dietary records during monthly visits for consecutive three months. Nutrients were analyzed using Nutritionist Professional software. Blood urea nitrogen (BUN), creatinine, albumin, total protein, hemoglobin, serum calcium, phosphorus, sodium, and potassium were assessed monthly. Total cholesterol and triglycerides were measured every three months. After three-month intervention, protein intake (percent of total calories), and serum albumin were significantly increased in three groups. Protein, phosphorus intake, and BUN were increased in two intervention groups. Total serum protein increased in control and milk protein groups, and creatinine increased the control group. Serum phosphorus was not significantly changed. Nutritional education alone, or combined with protein supplementation, significantly improve protein intake, and nutritional status by increasing serum albumin, but not serum phosphorus in hypoalbuminemic peritoneal dialysis patients.

High rates of protein intake are associated with an accelerated rate of decline of residual kidney function in incident peritoneal dialysis patients

BACKGROUND

Preservation of residual kidney function (RKF) is a relevant objective in peritoneal dialysis (PD) patients. The influence of dietary protein intake (PI) on this variable has not been adequately investigated.

METHODS

Following an observational design, we studied 336 patients incident on PD, with a minimum follow-up of 6 months. The main study variable was the mean PI [normalized rate of protein nitrogen appearance (nPNA)] during the first 4 months on PD. The main outcome variables were the absolute rate of decline of RKF and the proportion of patients presenting a >50% decay of their RKF during the first year of follow-up. We applied univariate and multivariate strategies of analysis, taking into consideration the main control variables bearing a correlation with nPNA and/or RKF.

RESULTS

Mean nPNA (first 4 months) was 1.23 ± 0.33 g/kg/day, while the overall rate of decline of RKF was -0.13 ± 0.29 mL/min/month; 69 patients (25.1%) had lost >50% of their initial RKF by the end of the first year. Univariate analysis disclosed consistent associations between the main study variable on one hand and baseline RKF (r = 0.32, P < 0.0005) and its rate of decline (r = -0.23, P < 0.0005) on the other. The latter two variables were also significantly correlated (r = -0.36, P < 0.0005). Multivariate analysis identified mean nPNA as an independent predictor of the rate of decline of RKF [odds ratio 1.09 per 0.10 g/kg/day, 95% confidence interval (CI) 0.99-1.19, P = 0.058] and, in particular, of the probability of losing >50% of the baseline RKF during the first year of treatment (odds ratio 1.15 per 0.10 g/kg/day, 95% CI 1.04-1.27, P = 0.006).

CONCLUSION

Higher rates of PI during the first months of therapy are associated with a faster decline of RKF among patients incident on PD. Our results underline the convenience of keeping an adequate balance between sufficient protein ingestion, to prevent malnutrition and wasting, and sensible restriction in stable, adequately nourished individuals with rates of intake in the higher range or above-recommended allowances.

Total protein or leucine intakes are not associated with handgrip strength in hemodialysis patients: A pilot study

BACKGROUND & AIMS

Inadequate protein intake is associated with lean body mass (LBM) loss. However, it is unclear whether high protein diet and leucine intake are associated with handgrip strength (HGS), a validated marker of muscle function. This study aims to: i) assess the prevalence of patients with low HGS; and ii) verify if HGS is correlated with high protein diet and leucine consumption in hemodialysis patients.

METHODS

This cross-sectional study analysed patients at two center hemodialysis (HD) clinic and sixty-two patients aged ∼39 years with length of time on HD ∼60 months undergoing HD was carried out. Body weight (kg), LBM (kg) and body fat mass (%) assessments were performed by dual-energy X-ray absorptiometry and height (m) through portable stadiometer. Body mass index (BMI) (kg/m²) was calculated using the body weight and height. HGS (kg) was measured using a hydraulic dynamometer. Fisher's exact test, Chi-square, Pearson's correlation, and logistic regression were done to test the hypothesis.

RESULTS

Out of 62 patients, 47 (75.8%) presented low HGS. In addition, no correlation was found between protein intake (if in percentage or g/kg/d) and HGS (r = 0.07, p = 0.58; r = -0.04, p = 0.70, respectively). Although there is a low correlation among leucine intake (g/d) and HGS (r = 0.39, p = 0.01), low HGS was not associated with leucine intake in the crude model (OR: 0.86 95%CI(0.60-1.24) p = 0.441), nor after adjustment for age, sex and BMI (OR: 0.84 95%CI(0.56-1.26), p = 0.422).

CONCLUSIONS

Approximately 75% of patients undergoing hemodialysis presented low HGS. Additionally, neither a high protein diet nor leucine intake was associated with the HGS values.

Association of lean body mass with nutritional parameters and mortality in hemodialysis patients: A long-term follow-up clinical study

Objective:

This study aimed to evaluate the correlation between lean body mass (LBM) and nutritional status in hemodialysis (HD) patients to better predict their long-term prognosis.

Methods:

Anthropometric body measurements and biochemical parameters were recorded from 222 patients on maintenance hemodialysis (MHD) at the Shanghai Pudong Hospital Hemodialysis Center. LBM was calculated using the serum creatinine index (LBM-SCR), mid-arm muscle circumference (LBM-MAMC), and dominant-arm hand-grip strength (LBM-HGS). Patient mortality and hospitalization were observed after 24 months.

Results:

LBMs measured from LBM-SCR and LBM-MAMC were associated with sex, body mass index (BMI), serum albumin, and serum creatinine (SCR) ( p < 0.05). Through three methods of LBM evaluation, low LBM was shown to be associated with a higher mortality in patients undergoing HD ( p < 0.05). In addition, the rate of hospitalization among these patients was significantly increased ( p < 0.05). Performing multivariate regression analysis using mortality and hospitalization as the dependent variable, we found LBM-SCR and LBM-HGS are strongly associated with hospitalization and mortality in HD patients, indicating LBM is an important factor in prediction of outcomes in those patients.

Conclusion:

LBM is associated with nutritional parameters in HD patients, and LBM-SCR, HGS, and MAMC are simple approaches for accurately predicting the patient’s risk of hospitalization and/or death.

Changes in geriatric nutritional risk index and risk of major adverse cardiac and cerebrovascular events in incident peritoneal dialysis patients

Background

Geriatric nutritional risk index (GNRI) is a validated nutritional assessment method, and lower GNRI values are closely associated with adverse clinical outcomes in dialysis patients. This study investigated the impact of changes in GNRI during the first year of dialysis on cardiovascular outcomes in incident peritoneal dialysis (PD) patients.

Methods

We reviewed medical records in 133 incident PD patients to determine GNRI at the start of PD and after 12 months. Patients were categorized into improved (delta GNRI > 0) and worsening/stationary (delta GNRI ≤ 0) groups. The primary outcome was major adverse cardiac and cerebrovascular events (MACCEs).

Results

During a mean follow-up of 51.1 months, the primary outcome was observed in 42 patients (31.6%). The baseline GNRI at PD initiation was not significantly associated with MACCEs (log-rank test, P = 0.40). However, the cumulative event-free rate was significantly lower in the worsening or stationary GNRI group than in the improved group (log-rank test, P = 0.004). Multivariate Cox analysis revealed that a worsening or stationary GNRI was independently associated with higher risk for MACCEs (hazard ratio, 2.47; 95% confidence interval, 1.15–5.29; P = 0.02). In subgroup analysis, patients with worsening or stationary GNRI were at significantly greater risk for MACCEs in both the lower (P = 0.04) and higher (P = 0.01) baseline GNRI groups.

Conclusion

Baseline GNRI was not associated with MACCEs, but patients with deteriorating or stationary nutritional status were at significantly greater risk for MACCEs, suggesting that serial monitoring of nutritional status is important to stratify cardiovascular risk in incident PD patients.

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.

Low prognostic nutritional index associated with cardiovascular disease mortality in incident peritoneal dialysis patients

PURPOSE

The prognostic nutritional index (PNI), a variable based on serum albumin concentration and total lymphocyte count in peripheral blood, is reported as a predictor of mortality in a variety of malignant tumor population. This study is aimed to evaluate whether PNI has prognostic value in patients on peritoneal dialysis (PD).

METHODS

This was a single-center, retrospective observational cohort study conducted in incident PD patients from January 1, 2006 to June 30, 2014, and followed until June 30, 2015. The associations of PNI levels with mortality were evaluated by Kaplan-Meier method and Cox proportional hazards models.

RESULTS

A total of 345 patients were included in this study. Median PNI level at baseline was 40.7 (range: 18.8-75.5) for all patients. During follow-up, 59 (17.1%) died during follow-up, among which 31 (52.5%) were due to cardiovascular diseases (CVD). In crude analysis, the patients with low PNI had a significant increase risk of CVD and all-cause mortality [hazard ratio (HR) 3.07, 95% confidence interval (CI) 1.51-6.25 and HR 2.18, 95% CI 1.28-3.72, respectively)]. After adjusting age, Davies comorbidity score, hemoglobin and leukocytes, the patients with low PNI still had a significant increased risk of CVD mortality (HR 2.37, 95% CI 1.10-5.12). However, there was no significant difference in risk of all-cause mortality (HR 1.72, 95% CI 0.97-3.06).

CONCLUSIONS

Low PNI at initiation of PD was independently associated with an increased CVD mortality.

A Simpler Creatinine Index Can Predict Long-Term Survival in Chinese Hemodialysis Patients

Background

Low lean body mass (LBM) is an indicator of malnutrition inflammation syndrome, which is common in hemodialysis (HD) patients. The creatinine index (CI) has been validated as a reliable method to estimate LBM and evaluate the protein-energy status of HD patients. However, the traditional creatinine index formula was complex. We sought to investigate the impact of CI derived from a new simple formula on Chinese HD patient outcomes.

Methods

In this retrospective cohort study, we enrolled 1269 patients who initiated HD between February 1981 and February 2012 and followed them until the end of February 2013. CI was calculated using the simple creatinine kinetic model (CKM) formula. Multiple linear regression analysis and Cox regression proportional hazard analysis were used to define independent variables and compare survival between groups.

Results

The 1269 HD patients were categorized into 3 groups according to the tertiles of calculated CI between men and women. Each group consisted of 423 patients (50.6% men, 49.4% women). Patients in the highest sex-specific tertile of CI had longer overall survival (HR, 0.46; P 0.002). BMI did not significantly associate with survival after adjustment (HR,0.99; P 0.613).

Conclusions

CI derived from the simple CKM formula serves as a good parameter than BMI to predict the survival of HD patients. The formula could extend its convenient use in clinical practice for HD patients.

[The specific nutritionnal care in peritoneal dialysis]

Protein energy wasting is a major complication in peritoneal dialysis. It is leading to a poor quality of life and increasing mortality. Diagnosis must be early, according to criteria defined by the International society of renal nutrition and metabolism. It is necessary to appropriate the diagnostic tools with dialysis method. The nutritional care is difficult in peritoneal dialysis. Indeed, studies are limited and practical nutrition is complex. In this point of view, we propose to treat guidelines for protein energy wasting, in peritoneal dialysis patients.

Trajectories of Serum Albumin Predict Survival of Peritoneal Dialysis Patients: A 15-year Follow-Up Study

Although initial serum albumin level is highly associated with overall and cardiovascular mortality in peritoneal dialysis (PD) patients, we consider that the dynamic change and trend of albumin after initiation of PD are also essential.We enrolled patients who received PD for more than 3 months from January 1999 to March 2014. We categorized these patients into 2 groups by the difference in serum albumin level (Δalbumin = difference between peak with initial albumin level = peak albumin level - initial albumin level) after PD. The patients with Δalbumin < 0.2 g/dL (median level) were considered as group A (n, number = 238) and those with Δalbumin ≥ 0.2 g/dL were considered as group B (n = 278). Further, we stratified these patients into quartiles: Q1 Δalbumin < -0.2 g/dL; Q2, -0.2 ≦∼ <0.2 g/dL; Q3, 0.2 ≦∼ <0.6 g/dL; and Q4, ≥0.6 g/dL. Regression analysis was performed to determine the correlation of initial albumin and Δalbumin.Group A patients presented with higher levels of serum albumin (3.71 ± 0.54 vs 3.04 ± 0.55 g/dL; P < 0.001) and hematocrit as well as better initial residual renal function. However, those in group A had lower serum albumin increment and downward-sloped trends after dialysis. In contrast, the albumin trend was upward sloped and the increment of albumin was remarkable in group B, despite the high prevalence of cardiovascular diseases and diabetes. Overtime, group A patients had poorer survival and experienced more frequent and longer hospitalizations. Group Q1 patients with least albumin increment had worst survival. Group Q4 patients with lowest initial albumin also had poor survival. Age, diabetes, cardiovascular diseases, BMI, initial albumin, and Δalbumin could affect patient outcomes independently. Regression analysis showed a better outcome can be obtained if the initial albumin level is at least above 3.15 g/dL. (Initial albumin level = -0.61 × Δalbumin + 3.50.)The increment and trend of albumin especially during early period of PD may be a more crucial determinant for survival.

Ketoacid Supplementation Partially Improves Metabolic Parameters in Patients on Peritoneal Dialysis

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BACKGROUND

A low protein diet supplemented with ketoacids has been shown to improve the metabolic profile, including insulin resistance, in patients with chronic kidney disease (CKD), but whether ketoacids alone exert similar effects is unknown. In this prospective randomized controlled trial, we aimed to evaluate the effects of ketoacid supplementation on insulin resistance, systemic inflammation, oxidative stress and endothelial dysfunction among 100 CKD patients undergoing peritoneal dialysis (PD). ♦

METHODS

Patients from one Chinese PD center were randomly assigned to take ketoacids (12 tablets per day) (n = 50) versus a control group (n = 50) for 6 months in an open-label parallelarm design. Daily protein intake of 0.8 - 1.2 g/kg/d and daily energy intake of 25 - 35 kcal/kg/d was prescribed to both groups. Insulin resistance was evaluated using homeostatic model assessment (HOMA-IR) index as the primary outcome. We assessed systemic inflammation using high-sensitive C-reactive protein (hs-CRP) and interleukin-6 (IL-6), oxidative stress using plasma oxidized low density lipoprotein (oxLDL), adipokines using leptin and adiponectin and endothelial dysfunction using serum soluble intercellular adhesion molecule-1 (sICAM) and soluble vascular adhesion molecule-1 (sVCAM) as secondary outcomes. ♦

RESULTS

There were no significant differences in baseline characteristics between the 2 groups except a slightly higher age in patients assigned to the intervention. A total of 89% of participants completed the 6-month intervention. There was no significant difference in the change of HOMA-IR values from baseline between groups after adjusting for baseline age, gender, body mass index and HOMA-IR. For secondary outcomes, hs-CRP varied significantly between groups (p = 0.02), increasing over time for the control group while remaining stable for the ketoacid group. Similarly, the leptin/adiponectin ratio (LAR) differed between groups (p < 0.001), remaining stable in the ketoacid group but increasing in the control group. ♦

CONCLUSION

Ketoacid therapy administered for 6 months had no effect on HOMA-IR but resulted in improvements in hs-CRP and LAR, suggesting metabolic benefit. Future studies are needed to confirm these results and any potential benefit in vascular health of PD patients.

The Effect of Fluid Overload on Clinical Outcome in Southern Chinese Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

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BACKGROUND

Fluid overload is frequently present in dialysis patients and one of the important predictors of patient outcome. This study aimed to investigate the influence of fluid overload on all-cause mortality and technique failure in Southern Chinese continuous ambulatory peritoneal dialysis (CAPD) patients. ♦

METHODS

This was a post hoc study from a cross-sectional survey originally designed to investigate the prevalence and associated risk factors of fluid overload defined by bioimpedance analysis (BIA) in CAPD patients from January 1, 2008, to December 31, 2009. All 307 CAPD patients completing the original study were followed up until December 31, 2012. ♦

RESULTS

With a median follow-up period of 38.4 (19.2 - 47.9) months, 52 patients died. Patients with fluid overload (defined by extracellular water/total body water [ECW/TBW] ≥ 0.40) had a significantly higher peritonitis rate (0.016 vs 0.011 events/month exposure, p = 0.018) and cerebrovascular event rate (3.9 vs 1.1 events/100 patient years, p = 0.024) than the normal hydrated patients. Moreover, the results showed a significant rising of all-cause mortality (log-rank test = 5.59, p = 0.018), and a trend of increasing cardiovascular disease (CVD) mortality (log-rank test = 2.90, p = 0.089) and technique failure (log-rank test = 3.78, p = 0.052) in the patients with fluid overload. Fluid overload independently predicted all-cause mortality (hazard ratio [HR] = 12.98, 95%, confidence interval [CI] = 1.06 - 168.23, p = 0.042) and technique failure (HR = 13.56, 95% CI = 2.53 - 78.69, p = 0.007) in CAPD patients after adjustment for confounders. ♦

CONCLUSIONS

Fluid overload defined by BIA was an independent predictor for all-cause mortality and technique failure in CAPD patients. Continuous ambulatory peritoneal dialysis patients with fluid overload had a higher peritonitis rate, cardiovascular event rate, and poorer clinical outcome than those patients with normal hydration.

Clinical research in a modern Chinese peritoneal dialysis center

A prerequisite for enhancing the quality of peritoneal dialysis is the continuous review and analysis of clinical data from routine clinical care and research. Here, we describe our strategy (Peking University First Hospital, Beijing, China) to achieve that objective.

Nutrition and the kidney: recommendations for peritoneal dialysis

Protein energy wasting (PEW) is highly prevalent in peritoneal dialysis (PD) and is associated with poor outcomes, including hospitalization and mortality. Recognizing and diagnosing PEW in PD is important; although studies are limited, there are interventions that may be associated with improved outcomes. In this review of nutritional aspects of PD, we highlight some of the important causes of PEW and explore the current diagnostic tools that are used to assess PEW. Finally, we discuss the established and experimental therapies for PEW in PD.

Lanthanum carbonate versus placebo for management of hyperphosphatemia in patients undergoing peritoneal dialysis: a subgroup analysis of a phase 2 randomized controlled study of dialysis patients

BACKGROUND

This short-term study assessed the efficacy and safety of lanthanum carbonate in the treatment of hyperphosphatemia in dialysis patients; here, we report a prespecified subgroup analysis of patients undergoing peritoneal dialysis.

METHODS

Men and women (n=39) who had received continuous ambulatory peritoneal dialysis for chronic kidney disease for 6 months or more were enrolled in eight renal medicine departments in the United Kingdom. A 2-week washout period was followed by a 4-week dose-titration phase during which patients received lanthanum carbonate titrated up to 2250 mg/day. This was followed by a 4-week, randomized, placebo-controlled, parallel-group phase during which patients continued to receive either lanthanum carbonate at the titrated dose, or a matched dose of placebo. The main outcome measure was control of serum phosphate levels (1.3-1.8 mmol/l) at the end of the parallel-group phase.

RESULTS

Serum phosphate was controlled in 3/39 (8%) patients at the beginning of the dose-titration phase (after washout) and in 18/31 (58%) patients treated with lanthanum carbonate at its end. After the parallel-group phase, 60% of lanthanum carbonate-treated patients and 10% of those receiving placebo had controlled serum phosphate. There was no difference in mean (95% confidence interval) serum phosphate levels between groups at randomization: lanthanum carbonate, 1.57 (1.34-1.81) mmol/l; placebo, 1.58 (1.40-1.76) mmol/l (p=0.96). However, a difference was seen at the end of the parallel-group phase: lanthanum carbonate, 1.56 (1.33-1.79) mmol/l; placebo, 2.25 (1.81-2.68) mmol/l (p=0.0015). There were no clinically important changes in nutritional parameters and no serious treatment-related adverse events were recorded.

CONCLUSIONS

At doses up to 2250 mg/day, lanthanum carbonate is well tolerated and controls hyperphosphatemia effectively. Treatment with higher doses of lanthanum carbonate may allow patients undergoing peritoneal dialysis the potential to increase their dietary protein intake without compromising their phosphate control.

Lean body mass predicts long-term survival in Chinese patients on peritoneal dialysis

Background

Reduced lean body mass (LBM) is one of the main indicators in malnutrition inflammation syndrome among patients on dialysis. However, the influence of LBM on peritoneal dialysis (PD) patients’ outcomes and the factors related to increasing LBM are seldom reported.

Methods

We enrolled 103 incident PD patients between 2002 and 2003, and followed them until December 2011. Clinical characteristics, PD-associated parameters, residual renal function, and serum chemistry profiles of each patient were collected at 1 month and 1 year after initiating PD. LBM was estimated using creatinine index corrected with body weight. Multiple linear regression analysis, Kaplan–Meier survival analysis, and Cox regression proportional hazard analysis were used to define independent variables and compare survival between groups.

Results

Using the median LBM value (70% for men and 64% for women), patients were divided into group 1 (n = 52; low LBM) and group 2 (n = 51; high LBM). Group 1 patients had higher rates of peritonitis (1.6 vs. 1.1/100 patient months; p<0.05) and hospitalization (14.6 vs. 9.7/100 patient months; p<0.05). Group 1 patients also had shorter overall survival and technique survival (p<0.01). Each percentage point increase in LBM reduced the hazard ratio for mortality by 8% after adjustment for diabetes, age, sex, and body mass index (BMI). Changes in residual renal function and protein catabolic rate were independently associated with changes in LBM in the first year of PD.

Conclusions

LBM serves as a good parameter in addition to BMI to predict the survival of patients on PD. Preserving residual renal function and increasing protein intake can increase LBM.

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.