Intradialytic protein supplementation reduces inflammation and improves physical function in maintenance hemodialysis patients

Whey Protein, Vitamins C and E Decrease Interleukin-10 in Chronic Hemodialysis Patients: A Pioneer, Randomized, Double-Blind Pilot Trial

OBJECTIVE

To evaluate the effects of supplementation with whey protein combined with vitamins C and E on inflammatory markers in hemodialysis (HD) patients.

DESIGN AND METHODS

This was a pioneer, randomized and double-blinded study. Patients were randomized into two groups and stratified by HD frequency. The supplementation group received 20 g of whey protein, 250 mg of vitamin C, and 600 IU of vitamin E; the placebo group, 20 g of rice flour, and microcrystalline cellulose capsules. The interventions were given after HD, 3 times a week, for 8 weeks. The inflammatory markers were assessed: interleukin (IL) IL-12p70, IL-10, IL-6, IL-8, and tumor necrosis factor alpha. For statistical analysis, the χ2 test, Student's t-test, Mann-Whitney test, analysis of variance for repeated two-way measurements, paired t test, and Wilcoxon test were performed. P < .05 was considered statistically significant.

RESULTS

Twenty-three patients completed the study. No significant differences were found in inflammatory markers when comparing the groups postintervention. In the intragroup was a decrease in IL-10 in the supplementation group after 8 weeks (P = .0382). IL-6 tended to decrease by 810.95% in the supplementation group and increased by 732.8% (nonsignificant) in the placebo group.

CONCLUSION

Whey protein combined with vitamins C and E significantly reduced IL-10 in the supplementation group and could be beneficial to reduce IL-6 in HD patients. Future studies are suggested with a larger sample size, different supplementation doses, and longer interventions.

Effects of oral nutritional supplements on the nutritional status and inflammatory markers in patients on maintenance dialysis: a systematic review and meta-analysis of randomized clinical trials

Background and aims

Patients on hemodialysis (HD) or peritoneal dialysis (PD) often have insufficient energy and protein intake, resulting in poor nutritional status and adverse outcomes. Oral nutritional supplements (ONSs) are the most commonly used to increase such patients' energy and protein intakes.

Methods

In this systematic review and meta-analysis, we analyzed studies on nutritional status, inflammatory markers, and electrolyte levels in patients on dialysis receiving ONSs. We searched four electronic databases from inception until 31 December 2022, for randomized controlled trials comparing ONS treatment versus placebo or routine care.

Results

22 studies with 1185 patients on dialysis were included in our meta-analysis. Compared with the control group, the ONS group exhibited significantly increased serum albumin levels [1.26 g/l (95%CI, 0.50-2.02, P < 0.0001; I2 = 80.4%)], body mass indexes (BMIs) [0.30 kg/m2 (95%CI, 0.09-0.52, P = 0.005; I2 = 41.4%)], and handgrip strength (HGS) [0.96 kg (95%CI, 0.07-1.84, P = 0.034; I2 = 41.4%)] from baseline to the end of intervention. No significant differences were observed between the groups in lean body mass, phase angle, C-reactive protein, and serum phosphorus and potassium levels. In terms of improving albumin, the subgroup analyses show that ONS use seems to be more inclined to three variations: HD patients, short-term use, and non-intradialytic supplementation.

Conclusion

In conclusion, ONS use can improve the nutritional status of patients on dialysis in terms of their serum albumin, BMI, and HGS without significant effects on serum phosphorus, potassium, and C-reactive protein levels. However, it remains uncertain whether these results translate to improvement in clinically relevant outcomes. Large-scale high-quality studies are still required in this population.

Synbiotics, prebiotics and probiotics for people with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a major public health problem affecting 13% of the global population. Prior research has indicated that CKD is associated with gut dysbiosis. Gut dysbiosis may lead to the development and/or progression of CKD, which in turn may in turn lead to gut dysbiosis as a result of uraemic toxins, intestinal wall oedema, metabolic acidosis, prolonged intestinal transit times, polypharmacy (frequent antibiotic exposures) and dietary restrictions used to treat CKD. Interventions such as synbiotics, prebiotics, and probiotics may improve the balance of the gut flora by altering intestinal pH, improving gut microbiota balance and enhancing gut barrier function (i.e. reducing gut permeability).

OBJECTIVES

This review aimed to evaluate the benefits and harms of synbiotics, prebiotics, and probiotics for people with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 9 October 2023 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

We included randomised controlled trials (RCTs) measuring and reporting the effects of synbiotics, prebiotics, or probiotics in any combination and any formulation given to people with CKD (CKD stages 1 to 5, including dialysis and kidney transplant). Two authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was independently carried out by two authors using a standard data extraction form. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Forty-five studies (2266 randomised participants) were included in this review. Study participants were adults (two studies in children) with CKD ranging from stages 1 to 5, with patients receiving and not receiving dialysis, of whom half also had diabetes and hypertension. No studies investigated the same synbiotic, prebiotic or probiotic of similar strains, doses, or frequencies. Most studies were judged to be low risk for selection bias, performance bias and reporting bias, unclear risk for detection bias and for control of confounding factors, and high risk for attrition and other biases. Compared to prebiotics, it is uncertain whether synbiotics improve estimated glomerular filtration rate (eGFR) at four weeks (1 study, 34 participants: MD -3.80 mL/min/1.73 m², 95% CI -17.98 to 10.38), indoxyl sulfate at four weeks (1 study, 42 participants: MD 128.30 ng/mL, 95% CI -242.77 to 499.37), change in gastrointestinal (GI) upset (borborymgi) at four weeks (1 study, 34 participants: RR 15.26, 95% CI 0.99 to 236.23), or change in GI upset (Gastrointestinal Symptom Rating Scale) at 12 months (1 study, 56 participants: MD 0.00, 95% CI -0.27 to 0.27), because the certainty of the evidence was very low. Compared to certain strains of prebiotics, it is uncertain whether a different strain of prebiotics improves eGFR at 12 weeks (1 study, 50 participants: MD 0.00 mL/min, 95% CI -1.73 to 1.73), indoxyl sulfate at six weeks (2 studies, 64 participants: MD -0.20 μg/mL, 95% CI -1.01 to 0.61; I² = 0%) or change in any GI upset, intolerance or microbiota composition, because the certainty of the evidence was very low. Compared to certain strains of probiotics, it is uncertain whether a different strain of probiotic improves eGFR at eight weeks (1 study, 30 participants: MD -0.64 mL/min, 95% CI -9.51 to 8.23; very low certainty evidence). Compared to placebo or no treatment, it is uncertain whether synbiotics improve eGFR at six or 12 weeks (2 studies, 98 participants: MD 1.42 mL/min, 95% CI 0.65 to 2.2) or change in any GI upset or intolerance at 12 weeks because the certainty of the evidence was very low. Compared to placebo or no treatment, it is uncertain whether prebiotics improves indoxyl sulfate at eight weeks (2 studies, 75 participants: SMD -0.14 mg/L, 95% CI -0.60 to 0.31; very low certainty evidence) or microbiota composition because the certainty of the evidence is very low. Compared to placebo or no treatment, it is uncertain whether probiotics improve eGFR at eight, 12 or 15 weeks (3 studies, 128 participants: MD 2.73 mL/min, 95% CI -2.28 to 7.75; I² = 78%), proteinuria at 12 or 24 weeks (1 study, 60 participants: MD -15.60 mg/dL, 95% CI -34.30 to 3.10), indoxyl sulfate at 12 or 24 weeks (2 studies, 83 participants: MD -4.42 mg/dL, 95% CI -9.83 to 1.35; I² = 0%), or any change in GI upset or intolerance because the certainty of the evidence was very low. Probiotics may have little or no effect on albuminuria at 12 or 24 weeks compared to placebo or no treatment (4 studies, 193 participants: MD 0.02 g/dL, 95% CI -0.08 to 0.13; I² = 0%; low certainty evidence). For all comparisons, adverse events were poorly reported and were minimal (flatulence, nausea, diarrhoea, abdominal pain) and non-serious, and withdrawals were not related to the study treatment.

AUTHORS' CONCLUSIONS

We found very few studies that adequately test biotic supplementation as alternative treatments for improving kidney function, GI symptoms, dialysis outcomes, allograft function, patient-reported outcomes, CVD, cancer, reducing uraemic toxins, and adverse effects. We are not certain whether synbiotics, prebiotics, or probiotics are more or less effective compared to one another, antibiotics, or standard care for improving patient outcomes in people with CKD. Adverse events were uncommon and mild.

Glycemic index of a nutritional supplement designed for people with chronic kidney disease

The study was carried out to measure the glycemic index (GI) of an oral food supplement for people with CKD as well as on patients on maintenance dialysis. The study was conducted as per international protocols for testing GI, was approved by the local institutional ethics committee, and was registered with the Clinical Trial Registry of India (CTRI). This was a crossover randomized controlled study which enrolled 15 participants between the ages of 18 and 45 years. The participants were randomly allotted to one group that consumed either the reference food (27.5 g of glucose monohydrate) or 118 g of the nutritional supplement which contained 25 g of available carbohydrates. Fasting capillary blood samples as well as blood samples at different time intervals as per the GI protocol, after consumption of either the supplement or the reference food were taken from the participants. Each testing day was separated by a 3-day washout period. GI was calculated from the incremental area under the blood glucose response elicited by the nutritional supplement as a percentage of the response after the consumption of 25 g of glucose (27.5 g of glucose monohydrate) by the same participant using a standard formula. The GI of the nutritional supplement was calculated to be 10.3 ± 2.0 which is considered to be low as per international GI testing standards. The product was created to supplement the diet of people with CKD at different stages and to help prevent the progression from CKD to ESRD as well as the risk for CVD. This product was found to have a low GI which is desirable for people with CKD as well as diabetics in general who are at risk for developing CKD.

Clinical features and molecular mechanism of muscle wasting in end stage renal disease

Muscle wasting in end-stage renal disease (ESRD) is an escalating issue due to the increasing global prevalence of ESRD and its significant clinical impact, including a close association with elevated mortality risk. The phenomenon of muscle wasting in ESRD, which exceeds the rate of muscle loss observed in the normal aging process, arises from multifactorial processes. This review paper aims to provide a comprehensive understanding of muscle wasting in ESRD, covering its epidemiology, underlying molecular mechanisms, and current and emerging therapeutic interventions. It delves into the assessment techniques for muscle mass and function, before exploring the intricate metabolic and molecular pathways that lead to muscle atrophy in ESRD patients. We further discuss various strategies to mitigate muscle wasting, including nutritional, pharmacological, exercise, and physical modalities intervention. This review seeks to provide a solid foundation for future research in this area, fostering a deeper understanding of muscle wasting in ESRD, and paving the way for the development of novel strategies to improve patient outcomes. [BMB Reports 2023; 56(8): 426-438].

Effect of intradialytic oral nutritional supplementation on nutritional markers in malnourished chronic hemodialysis patients: prospective randomized trial

BACKGROUND AND OBJECTIVES

Malnutrition is prevalent in chronic hemodialysis (HD) patients. It increases mortality and negatively affects quality of life. This study aimed to assess the effect of intradialytic oral nutritional supplement (ONS) on nutritional markers in chronic HD patients with protein energy wasting (PEW).

METHODS

This 3-month prospective, open-label, randomized controlled trial included 60 chronic HD patients with PEW. The intervention group (30 patients) received intradialytic ONS and dietary counseling, whereas the control group (30 patients) received only dietary counseling. Nutritional markers were measured at the beginning and end of the study.

RESULTS

The mean age of the patients was 54 ± 12.7 years, and that of the HD vintage was 64 ± 49.3 months. Compared to the control group, the intervention group showed a significant increase in serum albumin (p < 0.001), prealbumin (p < 0.001), cholesterol (p = 0.016), body mass index (BMI) (p = 0.019), serum creatinine/body surface area (BSA) (p = 0.016), and composite French PEW score (p = 0.002), as well as a significant decrease in high-sensitivity C-reactive protein (hs-CRP) (p = 0.001). The total iron binding capacity, normalized protein nitrogen appearance, and hemoglobin levels increased significantly in both groups.

CONCLUSION

Intradialytic ONS and dietary counseling for three months were more effective than dietary counseling alone in terms of improving nutritional status and inflammation in chronic HD patients, as evidenced by increases in serum albumin, prealbumin, BMI, serum creatinine/BSA, composite French PEW score, and a decrease in hs-CRP.

Effect on nutritional status and biomarkers of inflammation and oxidation of an oral nutritional supplement (with or without probiotics) in malnourished hemodialysis patients. A multicenter randomized clinical trial "Renacare Trial"

Background

Malnutrition in patients undergoing hemodialysis is frequent and associated with a reduction in muscular mass and strength, with an increment in biomarkers of inflammation and oxidation.

Materials and methods

Randomized, multicenter, parallel-group trial in malnourished hemodialysis patients with three groups [(1) control (C) individualized diet, (2) oral nutritional supplement-ONS- + placebo-SU- PL-, and (3) ONS + probiotics-SU-PR]; the trial was open regarding the intake of ONS or individualized diet recommendations, but double-blind for the intake of probiotics. We obtained, at baseline and after 3 and 6 months, anthropometric measurements, handgrip strength, bioelectrical impedance analysis (BIA), dietary records, and routine biochemical parameters. Inflammation and oxidation were determined using ELISA techniques (Versamax and ProcartaPlex multiplex Immunoassay). Results were analyzed by intention to treat.

Results

A total of 31 patients (11 corresponding to group C, 10 to SU-PL, and 10 to SU-PR) completed the 6-months trial. The two groups that took supplements significantly increased their protein calorie, fat (total and n-3), and fiber intake. Weight and fat-free mass (FFM) also increased significantly in the groups on supplements, both at 3 and 6 months, and dynamometry did so in the SU-PL group. At month 3, prealbumin and vitamin D were significantly increased in the SU-TOT (SU-PL + SU-PR) group. No changes were observed regarding levels of phosphorus and potassium in any of the groups. Urea increased significantly at 6 months in the SU-PL group. There were significant changes in some inflammation biomarkers in the groups on supplements during the intervention (brain-derived neurotrophic factor, bone morphogenetic protein-2, MCP-1, IL-1-beta, IL-10, IL-4, and IL-8). The total antioxidant capacity (TAC) increased significantly in the supplemented patients, with no significant changes observed in isoprostanes.

Conclusion

The specific ONS improved protein-calorie intake, nutritional status (mainly FFM), and some biomarkers of inflammation/oxidation. The addition of probiotics could have a synergistic effect with ONS in such biomarkers.

Clinical trail registration

https://clinicaltrials.gov/ct2/show/, identifier NCT03924089.

Effects of the Malnutrition-Eat Additional Meal (MEAM) Diet on the Serum Levels of Albumin and C-Reactive Protein in Hemodialysis Patients

The main objective of this project was to evaluate the efficiency of two kinds of nutritional intervention implemented in hemodialysis patients for 24 weeks (traditional nutritional intervention without a meal served before dialysis for group HG1, and nutritional intervention involving a meal served before dialysis for group HG2), and their impact on nutritional status and serum concentrations of C-reactive protein (CRP). Nutritional status and serum biochemical parameters were analyzed in the control group (CG, n = 70) and in two homogeneous groups of patients, HG1 (n = 35) and HG2 (n = 35). There was an interesting trend in both groups of patients connected with increased intake, mainly of energy and protein. In HG1, the greatest increase in energy intake was observed on Sundays, and in HG2 on the days with dialysis. In HG2, after 24 weeks of the nutritional intervention, an increase in serum albumin (p = 0.0157) and a decrease in CRP concentration (p = 0.0306) were observed, whereas in HG1 there was a decrease in serum albumin concentration (p = 0.0043) with no significant change in CRP concentration. The nutritional intervention applied, called the Malnutrition-Eat Additional Meal (MEAM) diet with an easily digestible meal served before dialysis, was aimed at improving the patients' nutritional status and the obtained results indicate the need not only for substantial reeducation of hemodialysis patients in the area of their diet, but also for undertaking further research and discussions on the possibility of ensuring adequate meals for hemodialysis patients before the dialysis procedure.

Longitudinal causal effect of modified creatinine index on all-cause mortality in patients with end-stage renal disease: Accounting for time-varying confounders using G-estimation

Background

Standard regression modeling may cause biased effect estimates in the presence of time-varying confounders affected by prior exposure. This study aimed to quantify the relationship between declining in modified creatinine index (MCI), as a surrogate marker of lean body mass, and mortality among end stage renal disease (ESRD) patients using G-estimation accounting appropriately for time-varying confounders.

Methods

A retrospective cohort of all registered ESRD patients (n = 553) was constructed over 8 years from 2011 to 2019, from 3 hemodialysis centers at Kerman, southeast of Iran. According to changes in MCI, patients were dichotomized to either the decline group or no-decline group. Subsequently the effect of interest was estimated using G-estimation and compared with accelerated failure time (AFT) Weibull models using two modelling strategies.

Results

Standard models demonstrated survival time ratios of 0.91 (95% confidence interval [95% CI]: 0.64 to 1.28) and 0.84 (95% CI: 0.58 to 1.23) in patients in the decline MCI group compared to those in no-decline MCI group. This effect was demonstrated to be 0.57 (-95% CI: 0.21 to 0.81) using G-estimation.

Conclusion

Declining in MCI increases mortality in patients with ESRD using G-estimation, while the AFT standard models yield biased effect estimate toward the null.

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.

Effects of oral non-protein calorie supplements on nutritional status among maintenance hemodialysis patients with protein-energy wasting: a multi-center randomized controlled trial

Protein-energy wasting (PEW) is prevalent in maintenance hemodialysis (MHD) patients, and is one of the major risk factors for poor outcomes and death. This study aimed to investigate the effects of non-protein calorie supplements on the nutritional status of MHD patients with PEW. MHD patients with PEW were enrolled in this multi-center, open-label, randomized controlled trial. Then, they were randomly assigned to the intervention group to receive the non-protein calorie supplements containing 280 kcal of energy every day for 6 months or the control group to complete all aspects of the study without receiving supplements. Patients in both groups received dietary counselling from dietitians. Data on nutritional assessments, anthropometric measurements, blood analysis and dietary recall were collected at the baseline and at six months from both groups. Statistical analyses were performed using analysis of covariance (ANCOVA) adjusted for sex and baseline values. Ninety-two MHD patients completed the study. A significant increase in the subjective global assessment (SGA) score was found in the intervention group compared with the control group (4.88 ± 1.41 vs. 4.40 ± 1.16, p = 0.044). The ratio of PEW patients (diagnosed with SGA ≤5) in the intervention group (61.2%) was also significantly lower than that in the control group (83.7%) (p < 0.001). Moreover, significant improvements in body mass index (20.81 ± 2.46 kg m^-2vs. 19.51 ± 2.60 kg m^-2, p < 0.001), nutrition risk screening 2002 (2.45 ± 1.40 vs. 3.12 ± 1.37, p = 0.038), mid-upper arm circumference (23.30 ± 2.78 cm vs. 21.75 ± 2.87 cm, p = 0.001), and mid-arm muscle circumference (20.51 ± 2.32 cm vs. 19.06 ± 2.92 cm, p = 0.005) were observed in the intervention group compared with the control group. Patients in the intervention group took in more dietary energy than the control group (26.96 ± 4.75 kcal per kg body weight per day vs. 24.33 ± 2.68 kcal per kg body weight per day, p < 0.001). In conclusion, non-protein calorie supplements may improve the nutritional status of MHD patients with PEW.

The Effect of Nutrition and Exercise on Body Composition, Exercise Capacity, and Physical Functioning in Advanced CKD Patients

Patients with stages 4 and 5 chronic kidney disease (CKD), and particularly chronic dialysis patients, commonly are found to have substantially reduced daily physical activity in comparison to age- and sex-matched normal adults. This reduction in physical activity is associated with a major decrease in physical exercise capacity and physical performance. The CKD patients are often physically deconditioned, and protein energy wasting (PEW) and frailty are commonly present. These disorders are of major concern because physical dysfunction, muscle atrophy, and reduced muscle strength are associated with poor quality of life and increased morbidity and mortality in CKD and chronic dialysis patients. Many randomized controlled clinical trials indicate that when CKD and chronic dialysis are provided nutritional supplements or undergo exercise training their skeletal muscle mass and exercise capacity often increase. It is not known whether the rise in skeletal muscle mass and exercise capacity associated with nutritional support or exercise training will reduce morbidity or mortality rates. A limitation of these clinical trials is that the sample sizes of the different treatment groups were small. The aim of this review is to discuss the effects of nutrition and exercise on body composition, exercise capacity, and physical functioning in advanced CKD patients.

The Effect of Non-Pharmacological and Pharmacological Interventions on Measures Associated with Sarcopenia in End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis provides a synthesis of the available evidence for the effects of interventions on outcome measures associated with sarcopenia in end-stage kidney disease (ESKD). Thirteen databases were searched, supplemented with internet and hand searching. Randomised controlled trials of non-pharmacological or pharmacological interventions in adults with ESKD were eligible. Trials were restricted to those which had reported measures of sarcopenia. Primary outcome measures were hand grip strength and sit-to-stand tests. Sixty-four trials were eligible (with nineteen being included in meta-analyses). Synthesised data indicated that intradialytic exercise increased hand grip strength (standardised mean difference, 0.58; 0.24 to 0.91; p = 0.0007; I2 = 40%), and sit-to-stand (STS) 60 score (mean difference, 3.74 repetitions; 2.35 to 5.14; p < 0.001; I2 = 0%). Intradialytic exercise alone, and protein supplementation alone, resulted in no statistically significant change in STS5 (−0.78 s; −1.86 to 0.30; p = 0.16; I2 = 0%), and STS30 (MD, 0.97 repetitions; −0.16 to 2.10; p = 0.09; I2 = 0%) performance, respectively. For secondary outcomes, L-carnitine and nandrolone-decanoate resulted in significant increases in muscle quantity in the dialysis population. Intradialytic exercise modifies measures of sarcopenia in the haemodialysis population; however, the majority of trials were low in quality. There is limited evidence for efficacious interventions in the peritoneal dialysis and transplant recipient populations.

Dosage of Dual-Protein Nutrition Differentially Impacts the Formation of Atherosclerosis in ApoE-/- Mice

Atherosclerosis (AS) is recognized as the original cause of most cardiovascular and cerebrovascular diseases. The dual-protein (DP) nutrition that consists of soy protein and whey protein is reported to be associated with a reduction in AS; however, the relationship between DP and AS remains ambiguous. Therefore, this study aimed to verify the effect of DP on AS and explore the optimal DP intake to improve AS. ApoE^−/− mice were administrated with low- (LDP), middle- (MDP), and high-dose (HDP) DP. The MDP group exhibited significant improvements in AS. In terms of lipid metabolism, the levels of plasma total triglyceride and LDL-C and the mRNA expression levels of Cyp7a1 and PCSK9 were markedly tuned in the MDP group. In addition, the MDP treatment group had a substantially lower inflammatory response and better intestinal barrier function than LDP and HDP groups. The species richness demonstrated by the Chao1 index was distinctly increased in the MDP group, and the relative abundance of intestinal-permeability-protective microbes Blautia and Akkermansia was significantly elevated. In summary, an adequate intake of DP was able to counteract atherosclerosis development in ApoE^−/− mice, and this study provides a scientific theoretical basis for the application of DP in the food and pharmaceutical fields.

Steady exercise improves hand grip and leg muscle strength in hemodialysis patients

Sarcopenia due to chronic inflammation and biochemical disturbances in chronic kidney disease is severer and more prevalent in hemodialysis (HD) patients. We longitudinally evaluated the hand grip strength (HGS) and leg muscle strength (LMS) and evaluated the role of exercise in muscle strength in HD patients. We screened (January, n=127) and followed up (June, n=110 and December 2020, n=104). HGS and LMS at single center by using digital hand and leg dynamometer. HGS (24.2 kg vs. 15.5 kg) and LMS (32.8 kg vs. 22.5 kg) were better in men (P<0.001 and P<0.001, respectively). Older patients (≥60 years) showed decreased LMS than others in women (P=0.01). Patients who performed steady home- or hospital-based exercise showed marginally higher HGS (23.1 kg vs. 19.8 kg, P=0.07) and significantly higher LMS (33.7 kg vs. 25.9 kg, P=0.004). Steady exercise improved LMS throughout the study period (30.3 kg vs. 33.2 kg from Jan to Jun 2020, P=0.004; 30.3 kg vs. 34.2 kg from Jan to Dec 2020, P=0.014). Multiple linear regression analysis proved steady exercise was independently associated with better HGS and LMS. Steady exercise showed greater impact on LMS in male patients with longer HD vintage (≥44 months) and on HGS in younger male patients with shorter HD vintage (<44 months). Steady exercise was an important determinant of muscle strength in HD patients. We need to encourage patients to steadily perform regular home- or group-exercise before sarcopenia develops.

Muscle Status Response to Oral Nutritional Supplementation in Hemodialysis Patients With Protein Energy Wasting: A Multi-Center Randomized, Open Label-Controlled Trial

Background: Muscle wasting, observed in patients with end-stage kidney disease and protein energy wasting (PEW), is associated with increased mortality for those on hemodialysis (HD). Oral nutritional supplementation (ONS) and nutrition counseling (NC) are treatment options for PEW but research targeting muscle status, as an outcome metric, is limited.

Aim: We compared the effects of combined treatment (ONS + NC) vs. NC alone on muscle status and nutritional parameters in HD patients with PEW.

Methods: This multi-center randomized, open label-controlled trial, registered under ClinicalTrials.gov (Identifier no. NCT04789031), recruited 56 HD patients identified with PEW using the International Society of Renal Nutrition and Metabolism criteria. Patients were randomly allocated to intervention (ONS + NC, n = 29) and control (NC, n = 27) groups. The ONS + NC received commercial renal-specific ONS providing 475 kcal and 21.7 g of protein daily for 6 months. Both groups also received standard NC during the study period. Differences in quadriceps muscle status assessed using ultrasound (US) imaging, arm muscle area and circumference, bio-impedance spectroscopy (BIS), and handgrip strength (HGS) methods were analyzed using the generalized linear model for repeated measures.

Results: Muscle indices as per US metrics indicated significance (p < 0.001) for group × time interaction only in the ONS + NC group, with increases by 8.3 and 7.7% for quadriceps muscle thickness and 4.5% for cross-sectional area (all p < 0.05). This effect was not observed for arm muscle area and circumference, BIS metrics and HGS in both the groups. ONS + NC compared to NC demonstrated increased dry weight (p = 0.039), mid-thigh girth (p = 0.004), serum prealbumin (p = 0.005), normalized protein catabolic rate (p = 0.025), and dietary intakes (p < 0.001), along with lower malnutrition–inflammation score (MIS) (p = 0.041). At the end of the study, lesser patients in the ONS + NC group were diagnosed with PEW (24.1%, p = 0.008) as they had achieved dietary adequacy with ONS provision.

Conclusion: Combination of ONS with NC was effective in treating PEW and contributed to a gain in the muscle status as assessed by the US, suggesting that the treatment for PEW requires nutritional optimization via ONS.

Comparison of intradialytic neuromuscular electrical stimulation and oral nutritional supplements in hemodialysis patients: study protocol for a multicenter, parallel-group, randomized controlled trial in Korea

Background

The prevalence of sarcopenia increases as renal function decreases, and a considerable number of hemodialysis (HD) patients have sarcopenia. Exercise and nutritional support are established interventions to prevent and treat sarcopenia. Recently, many studies evaluating intradialytic neuromuscular electrical stimulation (NMES) showed improvement of muscular strength and mass, functional capacity, and quality of life (QOL). However, there has been no research about the effect of simultaneous nutritional support and NMES in HD patients.

Methods

This is a 12-week, randomized controlled, parallel-group, multicenter trial of intradialytic NMES and protein supplementation for HD patients. Seventy-two patients receiving HD will be randomly assigned in a 1:1:1:1 ratio to control, intradialytic NMES only, protein supplementation only, and intradialytic NMES combined with protein supplementation groups. NMES will be delivered to a total of four areas of the bilateral vastus medialis and vastus lateralis using a 4-channel NMES instrument. A total of 25 g of protein supplements will be provided at the beginning of every dialysis session or after the NMES. The primary endpoint is the difference of hand grip and leg muscle strength at 12 weeks among 4 treatment groups. Secondary endpoints include muscle mass, physical performances, and questionnaires about QOL and physical activity.

Discussion

In this study, we will evaluate the differential effectiveness of nutritional support and NMES during HD on muscle strength, muscle mass, physical function, and QOL. We expect that this study can provide guidelines for a new therapeutic option for HD patients who are unable or hesitant to exercise. Furthermore, this option can offer an opportunity to improve the physical function, QOL, and prognosis of HD patients.

Trial registration

Clinical Research Information Service (CRIS), Korea, KCT0005573. Retrospectively registered on 03 November 2020

Dietary protein intake and the risk of all-cause and cardiovascular mortality in maintenance hemodialysis patients: A multicenter, prospective cohort study

OBJECTIVES

The association between dietary protein intake (DPI) and mortality in people receiving maintenance hemodialysis (MHD) remains uncertain. We aimed to explore the relationship of DPI with all-cause and cardiovascular (CV) mortality, and to examine the possible modifiers for the associations, in Chinese MHD patients.

METHODS

This multicenter prospective cohort study was conducted in eight outpatient dialysis centers in South China. We enrolled 1044 MHD patients in 2014 and 2015. The DPI was assessed using a 3-d 24-h dietary recall. Using Cox proportional hazard models, we estimated the hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) for all analyzed end points.

RESULTS

During a median follow-up of 45 mo, there were 354 (33.9%) deaths, 210 of which were CV related. Compared with patients with a DPI of 1.0 to < 1.4 g/kg ideal body weight (IBW)/d, a significantly higher risk of all-cause mortality was found in those with a DPI < 1.0 g/kg IBW/d (adjusted HR, 1.84; 95% CI, 1.42-2.38) or ≥ 1.4 g/kg IBW/d (adjusted HR, 1.49; 95% CI, 1.00-2.22). Similar trends were found for CV mortality. Moreover, we found a significantly stronger positive association between DPI (≥ 1.4 versus 1.0 to < 1.4 g/kg IBW/d) and all-cause mortality in women (adjusted HR, 2.05; 95% CI, 1.00-4.22) than in men (adjusted HR, 0.89; 95% CI, 0.49-1.63; P for interaction = 0.0487).

CONCLUSION

In Chinese MHD patients, a DPI of 1.0 to < 1.4 g/kg IBW/d was associated with lower risks of all-cause and CV mortality.

The effect of soy products on circulating adiponectin and leptin concentration in adults: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Human clinical trials that have investigated the effect of soy product consumption on adipokines have reported inconsistent results. Our objective was to elucidate the role of soy product consumption on adiponectin and leptin in adults through a systematic review and meta-analysis of available randomised placebo-controlled trials (RCTs).

METHODS

The systematic search included PubMed, Scopus, Web of Science, EmBase, Google Scholar and Cochrane database from inception to July 2020. Human clinical trials that reported the effect of soy product consumption on leptin and adiponectin were included. The pooled weighted mean difference (WMD) was calculated by the random-effects model. Heterogeneity, sensitivity analysis, and publication bias were reported using standard methods. Quality assessment was performed using Cochrane risk of bias assessment tool.

RESULTS

Overall, 13 RCTs with 824 participants were included in this meta-analysis. Our analysis showed that soy product consumption did not significantly affect leptin (WMD: 0.01 ng/mL; 95% CI, -0.16, 0.18; P = .88) and adiponectin (WMD: -0.09 ng/mL; 95% CI, -0.29, 0.12; P = .39) concentration in comparison with control. Furthermore, subgroup analysis indicated that the effect remained non-significant when analysed by study design, participant demographics and intervention characteristics. Based on the Cochrane Collaboration Risk of Bias tool, seven studies were considered good quality and six studies were fair.

CONCLUSION

The present systematic review and meta-analysis suggest that soy product consumption had no significant effect on leptin and adiponectin levels in adults. However, future larger and well-designed trials are still needed to further explore this research area and to address the heterogeneous study design used in the existing literature.

Post-COVID-19 rehabilitation: a special look at chronic kidney disease patients

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect the kidney and the presence of chronic kidney disease (CKD) constitutes a higher risk of negative prognosis. SARS-CoV-2 main sequelae in CKD patients are an incomplete recovery of kidney function, muscle weakness and atrophy, breathiness, tiredness, pulmonary fibrosis, and initiation of kidney replacement therapy. The overall aim of this review is to provide a theoretical basis for early improvements of physical function health to all CKD stages by rehabilitation therapies.

CONCLUSION

Chronic kidney disease patients infected with SARS-CoV-2 should be monitored by rehabilitation professionals as the cardiopulmonary, musculoskeletal, and cognitive systems might be deteriorated. Long-term consequences of SARS-CoV-2 are unknown and preventive rehabilitation may attenuate them.

Chronic Kidney Disease and Nutrition Support

Individuals with chronic kidney disease (CKD), particularly those undergoing maintenance dialysis, are prone to protein-energy wasting (PEW), the latter of which can be ameliorated with different methods of nutrition support. Dietary counseling guided by dietitians is the key for preventing and managing PEW in CKD. If dietary counseling per se fails to meet the recommended energy and protein requirements, the addition of oral nutrition supplements (ONSs) would be necessary. When these initial measures cannot attain the recommended energy and protein requirements, nutrition support, including enteral tube feeding or parenteral nutrition (PN), should be considered as a viable option to improve nutrition status. Partial PN, comprising intraperitoneal PN (IPPN) and intradialytic PN (IDPN) therapies, may be attempted as supplemental nutrition support in patients with PEW requiring peritoneal dialysis and hemodialysis, respectively. Despite the debatable effectiveness of IPPN for patients undergoing peritoneal dialysis, it remains a feasible means in these patients. The indications for IPPN in patients undergoing peritoneal dialysis include inadequate dietary intake of energy and protein, and barriers of oral intake and other forms of enteral supplementation such as issues with suitability, tolerance, and compliance. Nonetheless, in the case of spontaneous dietary consumption of energy and protein meeting the difference between the IDPN provision and the nutrition targets, the use of IDPN is rational. In patients with PEW and malfunctioning gastrointestinal tract, as well as those whose enteral intake (with or without partial PN) is below the recommended nutrient requirements, total PN becomes a relevant nutrition intervention.

Animal Protein versus Plant Protein in Supporting Lean Mass and Muscle Strength: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass and muscle strength needs to be systematically reviewed. This study aimed to examine potential differences in the effect of animal vs. plant protein on lean mass and muscle strength, and the possible influence of resistance exercise training (RET) and age. The following databases were searched: PubMed, Embase, Scopus and CINAHL Plus with Full Text, and 3081 articles were screened. A total of 18 articles were selected for systematic review, of which, 16 were used for meta-analysis. Total protein intakes were generally above the recommended dietary allowance at the baseline and end of intervention. Results from the meta-analyses demonstrated that protein source did not affect changes in absolute lean mass or muscle strength. However, there was a favoring effect of animal protein on percent lean mass. RET had no influence on the results, while younger adults (<50 years) were found to gain absolute and percent lean mass with animal protein intake (weighted mean difference (WMD), 0.41 kg; 95% confidence interval (CI) 0.08 to 0.74; WMD 0.50%; 95% CI 0.00 to 1.01). Collectively, animal protein tends to be more beneficial for lean mass than plant protein, especially in younger adults.

Functional foods modulating inflammation and metabolism in chronic diseases: a systematic review

Chronic diseases are responsible for approximately 71% global deaths. These are characterized by chronic low-grade inflammation and metabolic alterations. "Functional foods" have been attributed with anti-inflammatory properties, demonstrated in cell lines and murine models; however, studies in humans are inconclusive. The purpose of this systematic review is to identify clinical trials that analyzed changes in inflammatory and metabolic mediators, in response to consumption of specific functional foods. A total of 3581 trials were screened and 88 were included for this review. Foods identified to regulate inflammation included cranberries, grapes, pomegranate, strawberries, wheat, whole grain products, low fat dairy products, yogurt, green tea, cardamom, turmeric, soy foods, almonds, chia seeds, flaxseed, pistachios, algae oil, flaxseed oil and grape seed oil. Clinical trials that focus on a dietary pattern rich in functional foods are necessary to explore if the additive effect of these foods lead to more clinically relevant outcomes.

Effectiveness of renal-specific oral nutritional supplements compared with diet counseling in malnourished hemodialysis patients

BACKGROUND

Malnutrition is highly prevalent and a consequence of inflammation and related comorbidities among patients on maintenance hemodialysis. Oral nutritional supplementation (ONS) is recommended for malnourished patients with kidney failure. The study aimed to evaluate renal-specific oral nutrition (ONCE dialyze) supplement on nutritional status in patients on hemodialysis.

METHODS

Patients were randomized into 3 groups; treatment groups received 370 kcal/day of ONCE Dialyze (N = 26) or 370 kcal/day of NEPRO (N = 30) for 30 days. The control group (N = 24) received no intervention. All patients were counseled by the same registered dietitian during the study. The nutritional status was evaluated using malnutrition inflammation score (MIS) assessment, body compositions, serum albumin and pre-albumin levels at baseline and 30 days.

RESULTS

Eighty patients were analyzed with mean age of 57.2 ± 15.9 years. The intervention group exhibited significant improvements in energy, protein, fat, fiber and magnesium intake by dietary interview compared with the control group. Percentage of changes in MIS was - 29.0% (95% CI - 40.5 to - 17.4), - 23.9% (95% CI - 37.2 to - 10.6) and 12.1% (95% CI - 19.2 to 43.4) for the ONCE dialyze, NEPRO and control groups, respectively (overall P = 0.006). Percentage of changes in serum albumin was 5.3% (95% CI 1.9-8.7), 3.3% (95% CI - 0.1 to 6.7) and - 0.8% (95% CI - 4.3 to 2.7) for the ONCE dialyze, NEPRO, and control groups, respectively (overall P = 0.039; P = 0.043 for ONCE dialyze vs. control). No serious adverse effects were reported in any group.

CONCLUSION

Dietary advice combined with ONS especially ONCE dialyze was associated with improved MIS, serum albumin, dietary energy and macronutrient intake among patients with kidney failure on maintenance hemodialysis.

CLINICAL TRIAL REGISTRATION

TCTR20200801001.

The combination of malnutrition-inflammation and functional status limitations is associated with mortality in hemodialysis patients

The identification of malnutrition-inflammation-complex (MIC) and functional status (FS) is key to improving patient experience on hemodialysis (HD). We investigate the association of MIC and FS combinations with mortality in HD patients. We analyzed data from 5630 HD patients from 9 countries in DOPPS phases 4–5 (2009–2015) with a median follow-up of 23 [IQR 11, 31] months. MIC was defined as serum albumin < 3.8 g/dL and serum C-reactive protein > 3 mg/L in Japan and > 10 mg/L elsewhere. FS score was defined as the sum of scores from the Katz Index of Independence in Activities of Daily Living and the Lawton-Brody Instrumental Activities of Daily Living Scale. We investigated the association between combinations of MIC (+/−) and FS (low [< 11]/high [≥ 11]) with death. Compared to the reference group (MIC−/high FS), the adjusted hazard ratios [HR (95% CI)] for all-cause mortality were 1.82 (1.49, 2.21) for MIC−/low FS, 1.57 (1.30, 1.89) for MIC+/high FS, and 3.44 (2.80, 4.23) for MIC+/low FS groups. Similar associations were observed with CVD-related and infection-related mortality. The combination of MIC and low FS is a strong predictor of mortality in HD patients. Identification of MIC and poor FS may direct interventions to lessen adverse clinical outcomes in the HD setting.

Effects of soy intake on circulating levels of TNF-α and interleukin-6: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Pro-inflammatory mediators, including serum tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), can be used as biomarkers to indicate or monitor disease. This study was designed to ascertain the effects of soy products on TNF-α and IL-6 levels.

METHODS

PubMed, EMBASE, Science Direct, Web of Science, Google Scholar and the Cochrane Central Register of Controlled Trials were searched to November 2019 for RCTs around the effects of soy-based products on TNF-α and IL-6. A random effects model was used to calculate overall effect size.

RESULTS

In total, 29 eligible publications were considered in the present systematic review, of which 25 were included in this meta-analysis. The overall effect of soy products on TNF-α and IL-6 levels failed to reach statistical significance (MD = - 0.07; 95% CI - 0.22-0.09; I² 50.9; MD = 0.03; 95% CI - 0.07-0.14; I² 42.1, respectively). According to a subgroup analysis, natural soy products led to a reduction in TNF-α concentration compared with processed soy products (MD = - 0.32; 95% CI - 0.45 to - 0.19; I² 0.0). Moreover, IL-6 reduction was stronger in participants who were affected by different diseases (MD = - 0.04; 95% CI - 0.07 to - 0.02; I² 0.0).

CONCLUSIONS

A review of RCTs published to November 2019 found that natural soy products are effective in lowering TNF-α levels. While the beneficial effects on reduction of IL-6 appeared stronger in individuals affected by different diseases, this finding cannot be generalized to all individuals affected by different diseases.

The effect of oral nutritional supplement on muscle fitness of patients undergoing dialysis: A systematic review and meta-analysis

AIM

To summarize evidence regarding the effects of oral nutritional supplement on muscle fitness of patients undergoing dialysis.

DESIGN

A systematic review and meta-analysis.

REVIEW SOURCES

Five English databases (CENTRAL, PubMed, EMBASE, CINHAL, and Web of Science) and four Chinese databases (CNKI, WanFang, SinoMed, and VIP) were searched from inception to 31 July 2019 and only randomized controlled trials were included.

REVIEW METHODS

Two reviewers independently searched these databases, selected trials, conducted bias assessment, extracted the data. Random-effects meta-analysis was conducted to assess the effect size. The predetermined subgroup included type of oral nutritional supplement (a mixture of macronutrients, whey protein, essential amino-acids, and other nutrients) and intervention duration (over and less than 48 weeks). The subgroup analyses and sensitivity analyses were conducted to explore source of heterogeneity and robustness of results.

RESULTS

Sixteen studies (910 participants) meeting the inclusion criteria were identified and included in this systematic review. Subgroup analysis showed that supplying a mixture of macronutrients (MD [MD] = 2.36 kg, 95% CI [0.45, 4.26], I²  = 0.00%), an intervention duration of 48 weeks (MD = 4.05 kg, 95% CI [1.43, 6.67], I²  = 0.00%) had some effects on increasing lean body mass. No effects of oral nutritional supplement were found on improving muscle strength or physical performance.

CONCLUSION

A mixture of macronutrients and an intervention duration as long as 48 weeks had some significant effects on improving lean body mass of patients undergoing dialysis. No effect of oral nutritional supplement on muscle strength or physical performance were found but with limited evidence.

IMPACT

No existing reviews have ever focused on improving muscle fitness of patients undergoing dialysis. This systematic review and meta-analysis provided evidence of oral nutritional supplement on keeping muscle fitness of these patients and suggested possible type of oral nutritional supplement and intervention duration for clinical practice.

The effects of soy supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Soy products contain several compounds with anti-inflammatory properties like genistein and daidzein which reported to act through different pathways. Present study conducted considering the inconsistent results and lack of any comprehensive review regarding randomized controlled trials which assess the effect of soy products on inflammatory markers.

METHODS

Following electronic databases were searched up to March 2020: PubMed, Scopus, ISI web of science, and Cochrane Library All randomized trials which assessed the effect of soy product supplementation on c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were included for last analysis. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect the random-effects model was employed.

RESULTS

Finally, 51 randomized trial were included for present study. Last analysis showed that soy product supplementation lead to significant reduction in CRP (MD -0.27 mg/L; 95% CI: -0.51, -0.02, p = 0.028) but it did not affect IL-6 (MD 0.0 pg/ml; 95% CI: -0.06, 0.06, p = 0.970) and TNF-α (MD = -0.04 pg/ml; 95% CI: -0.11, 0.03, p = 0.252). Subgroup analysis showed that soy supplementation had a significant impact on decreasing IL-6 and TNF-α levels when studies had a long-term intervention (≥12 weeks) and used low dose isoflavone (<100 mg/day).

CONCLUSION

In conclusion, present systematic review and meta-analysis found a significant reduction in CRP levels after soy supplementation whiles IL-6 and TNF-α did not affect.

The effect of protein-enriched snacks on serum albumin concentration in non-selected haemodialysis patients

OBJECTIVE

Serum albumin level is not only one of the protein-energy wasting criteria but also a powerful marker of mortality in patients on haemodialysis (HD) treatment. The study aimed to assess the effect of a protein-enriched snack given during HD treatment on serum albumin level.

DESIGN AND METHODS

This prospective, single-centre, observational, non-randomized 16-month study was sub-divided into four 4-month periods. Patients on hemodialysis for more than three months and receiving a regular standard snack (8.8 g of protein) during the HD session were included and assigned during four four-month periods to receive either the standard snack or a protein-enriched snack (28.7 g). Patients were not selected based on nutritional criteria.

RESULTS

Sixty-six patients completed the study. Serum albumin levels significantly increased, from 3.43 ± 0.28 g/dl in the first period (standard snack) to 3.62 ± 0.32 g/dl (p < 0.0001) in the second period (enriched snack). In the third period (standard snack), albumin levels remained stable (3.61 ± 0.35 g/dl). After the fourth period (enriched snack), serum albumin levels further increased significantly (3.69 ± 0.30 g/dl; p = 0.05 and p = 0.007, respectively). Weight and normalized protein nitrogen appearance remained stable during the 16-month study period.

CONCLUSIONS

This study suggests that the intake of a protein-enriched snack during HD treatment, independently from baseline serum albumin level, could significantly increase their serum albumin levels. Serum albumin level is a powerful predictor of mortality; therefore, this simple and effective action could be of real interest to improve patients' outcomes.

Development of muffins as dialysis snacks for patients undergoing hemodialysis: results of chemical composition and sensory analysis

Objective

This study aimed to develop two non-industrial food products as financially accessible options to prevent and treat malnutrition in hemodialysis (HD) patients. These food products were developed and intended for use as dialysis snacks.

Methods

This is a cross-sectional and multi-step study. First, 183 adult HD patients (55 ± 14 years; 50.8% males), replied to a questionnaire with their food preferences regarding taste (salty, sweet, bitter, sour) and consistency (liquid, solid, pasty) for a dialysis snack. Most patients preferred a food product with a solid consistency (90%) and a salty flavor (81.4%). Second, three muffin formulations of fine herbs were developed; one enriched with whey protein concentrate (WPC), a second with textured soy protein (TSP) and a third standard formulation without protein for comparison with the protein-enriched muffins, for which the chemical and nutritional compositions were analyzed. In the third step, 60 patients on HD (61 ± 15 years; 53% males) were enrolled in a sensory analysis by applying a 9-point structured hedonic scale, ranging from “extremely liked” (score 9) to “extremely disliked” (score 1).

Results

When compared with the standard formulation, the formulations enriched with WPC and TSP protein had a significantly higher amount of protein/serving (Standard: 5.9 ± 0.3 g vs WPC: 14.5 ± 0.9 g and TSP 10.8 ± 0.7 g; P < 0.05) but a lower amount of carbohydrate (Standard: 13.1 ± 2.2 g vs WPC: 5.6 ± 0.8 g and TSP 6.0 ± 1.2 g vs; P < 0.05). The mineral content/serving of the protein-enriched muffins was low in phosphorus (50 mg) and sodium (180 mg). The potassium content/serving was moderate for the WPC muffin (225.2 mg) and low for the TSP muffin (107.9 mg). The acceptability index (AI) for the enriched protein muffins was higher than 70% and similar to the standard formulation.

Conclusion

The muffins with fine herbs and enriched with protein were well-accepted by all patients and appropriate to serve as dialysis snacks for HD patients.

Limitations of Existing Dialysis Diet Apps in Promoting User Engagement and Patient Self-Management: Quantitative Content Analysis Study

Background

With the unprecedented growth of mobile technology, a plethora of dialysis diet apps have been developed to promote patient dietary self-management. Nevertheless, the utility of such apps remains questionable.

Objective

This study aimed to evaluate the content, features, and quality of commercial dialysis diet apps for adult dialysis patients.

Methods

This study consisted of a quantitative content analysis of commercial dialysis diet apps downloaded from Google Play and the Apple App Store available in the Asian marketplace, searched for using the following keywords in English: dialysis diet and diet for kidney disease. Free and paid apps available in English that provide nutrition information for adult dialysis patients were included. Apps that were not relevant to the dialysis diet, not meant for patient self-management, or redundant were excluded. Apps were evaluated for language medium (subscore=1), credibility (subscore=1), food database (subscore=1), valuable features (subscore=12), health-behavior theory constructs (subscore=60), and technical quality (subscore=25). The relationships among the variables of interest were determined by Pearson correlation. Stepwise multiple linear regression analysis was performed to identify the features that contribute to greater technical quality of dialysis diet apps. Statistical significance was defined as P<.05.

Results

A total of 22 out of 253 apps (8.7%) were eligible for evaluation. Based on a 100-point scale, the mean overall score of the apps was 31.30 (SD 14.28). Only 5% (1/22) of the apps offered relevant language options, and 46% (10/22) contained food databases. In addition, 54% (12/22) of the apps were not credible. The mean score for valuable features was 3.45 (SD 1.63) out of 12, in which general education (16/22, 73%), free download (15/22, 68%), and usability (13/22, 59%) were the three most popular features. However, the apps scored a mean of 13.41 (SD 11.56) out of 60 for health-behavior theory constructs. The overall app technical quality was considered poor, with a mean score of 2.70 (SD 0.41) out of 5. The scores of valuable features (r=.65, P=.001) and health-behavior theory constructs (r=.55, P=.009) were positively correlated with the overall technical quality of the commercial dialysis diet apps. Features such as free download (β=.43, P=.03) and usability (β=.41, P=.03) could significantly determine the functional quality of the apps. Health-behavior theory constructs such as self-monitoring could significantly predict both the subjective quality (β=.55, P=.008) and the engagement quality (β=.66, P=.001) of the apps, whereas the information quality domain could be determined by plan or orders (β=.48, P=.007) and knowledge (β=.45, P=.01).

Conclusions

Although most of the available commercial dialysis diet apps are free and easy to use, they are subject to theory deficiency, limited language options, and a lack of food databases, credibility, tailored education, and overall technical quality.

Oral protein-based supplements versus placebo or no treatment for people with chronic kidney disease requiring dialysis

BACKGROUND

Malnutrition is common in patients with chronic kidney disease (CKD) on dialysis. Oral protein-based nutritional supplements are often provided to patients whose oral intake is otherwise insufficient to meet their energy and protein needs. Evidence for the effectiveness of oral protein-based nutritional supplements in this population is limited.

OBJECTIVES

The aims of this review were to determine the benefits and harms of using oral protein-based nutritional supplements to improve the nutritional state of patients with CKD requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 12 December 2019 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 Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of patients with CKD requiring dialysis that compared oral protein-based nutritional supplements to no oral protein-based nutritional supplements or placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility, risk of bias, and extracted data from individual studies. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference and 95% CI for continuous outcomes.

MAIN RESULTS

Twenty-two studies (1278 participants) were included in this review. All participants were adults on maintenance dialysis of whom 79% were on haemodialysis (HD) and 21% peritoneal dialysis. The follow-up period ranged from one to 12 months. The majority of studies were at unclear risk of selection, performance, and reporting bias. The detection bias was high for self-reported outcomes. Oral protein-based nutritional supplements probably lead to a higher mean change in serum albumin compared to the control group (16 studies, 790 participants: MD 0.19 g/dL, 95% CI 0.05 to 0.33; moderate certainty evidence), although there was considerable heterogeneity in the combined analysis (I² = 84%). The increase was more evident in HD participants (10 studies, 526 participants: MD 0.28 g/dL, 95% CI 0.11 to 0.46; P = 0.001 for overall effect) and malnourished participants (8 studies, 405 participants: MD 0.31 g/dL, 95% CI 0.10 to 0.52, P = 0.003 for overall effect). Oral protein-based nutritional supplements also probably leads to a higher mean serum albumin at the end of the intervention (14 studies, 715 participants: MD 0.14 g/dL, 95% CI 0 to 0.27; moderate certainty evidence), however heterogeneity was again high (I² = 80%). Again the increase was more evident in HD participants (9 studies, 498 participants: MD 0.21 g/dL, 95% CI 0.03 to 0.38; P = 0.02 for overall effect) and malnourished participants (7 studies, 377 participants: MD 0.25 g/dL, 95% CI 0.02 to 0.47; P = 0.03 for overall effect). Compared to placebo or no supplement, low certainty evidence showed oral protein-based nutritional supplements may result in a higher serum prealbumin (4 studies, 225 participants: MD 2.81 mg/dL, 95% CI 2.19 to 3.43), and mid-arm muscle circumference (4 studies, 216 participants: MD 1.33 cm, 95% CI 0.24 to 2.43) at the end of the intervention. Compared to placebo or no supplement, oral protein-based nutritional supplements may make little or no difference to weight (8 studies, 365 participants: MD 2.83 kg, 95% CI -0.43 to 6.09; low certainty evidence), body mass index (9 studies, 368 participants: MD -0.04 kg/m², 95% CI -0.74 to 0.66; moderate certainty evidence) and lean mass (5 studies, 189 participants: MD 1.27 kg, 95% CI -1.61 to 4.51; low certainty evidence). Due to very low quality of evidence, it is uncertain whether oral protein-based nutritional supplements affect triceps skinfold thickness, mid-arm circumference, C-reactive protein, Interleukin 6, serum potassium, or serum phosphate. There may be little or no difference in the risk of developing gastrointestinal intolerance between participants who received oral protein-based nutritional supplements compared with placebo or no supplement (6 studies, 426 participants: RR 2.81, 95% CI 0.58 to 13.65, low certainty evidence). It was not possible to draw conclusions about cost or quality of life, and deaths were not reported as a study outcome in any of the included studies.

AUTHORS' CONCLUSIONS

Overall, it is likely that oral protein-based nutritional supplements increase both mean change in serum albumin and serum albumin at end of intervention and may improve serum prealbumin and mid-arm muscle circumference. The improvement in serum albumin was more evident in haemodialysis and malnourished participants. However, it remains uncertain whether these results translate to improvement in nutritional status and clinically relevant outcomes such as death. Large well-designed RCTs in this population are required.

Impact of soy consumption on human health: integrative review

Abstract Soy consumption is a millenary habit of populations of the eastern world and has recently increased in the western world. The risks and benefits of this practice have been extensively studied, with a current fundamental need of integration of available information. The aim of this study was to carry out an integrative review on this topic, in order to consolidate the available information. Based on the main question: “What is the impact of soy consumption on human health?”, were reviewed publications classified as original articles and reviews published from 1998 to 2020 in the databases Scopus, PubMed, SciELO, Web of Science, and Cochrane Library. A total of 97 studies were selected. In the present review were described the general impact of soy on human health and its protein quality, the effects of early exposure using soy formulas, and the effects of soy consumption on breast cancer, endometrial and ovarian cancer, prostate cancer, gastrointestinal cancer, cardiovascular disease, glucose metabolism and type 2 diabetes, obesity, reproductive health, menopause, female and male osteoporosis, microbiota, immunity and immunomodulation, thyroid function, attention-deficit hyperactivity disorder, and renal function.

Dietary Protein and Physical Activity Interventions to Support Muscle Maintenance in End-Stage Renal Disease Patients on Hemodialysis

End-stage renal disease patients have insufficient renal clearance capacity left to adequately excrete metabolic waste products. Hemodialysis (HD) is often employed to partially replace renal clearance in these patients. However, skeletal muscle mass and strength start to decline at an accelerated rate after initiation of chronic HD therapy. An essential anabolic stimulus to allow muscle maintenance is dietary protein ingestion. Chronic HD patients generally fail to achieve recommended protein intake levels, in particular on dialysis days. Besides a low protein intake on dialysis days, the protein equivalent of a meal is extracted from the circulation during HD. Apart from protein ingestion, physical activity is essential to allow muscle maintenance. Unfortunately, most chronic HD patients have a sedentary lifestyle. Yet, physical activity and nutritional interventions to support muscle maintenance are generally not implemented in routine patient care. To support muscle maintenance in chronic HD patients, quantity and timing of protein intake should be optimized, in particular throughout dialysis days. Furthermore, implementing physical activity either during or between HD sessions may improve the muscle protein synthetic response to protein ingestion. A well-orchestrated combination of physical activity and nutritional interventions will be instrumental to preserve muscle mass in chronic HD patients.

Effects of intradialytic resistance exercise on systemic inflammation in maintenance hemodialysis patients with sarcopenia: a randomized controlled trial

PURPOSE

To investigate the effect of intradialytic resistance exercise on inflammation markers and sarcopenia indices in maintenance hemodialysis (MHD) patients with sarcopenia.

METHODS

Forty-one MHD patients with sarcopenia were divided into an intervention group (group E, n = 21) and a control group (group C, n = 20). Group C patients only received routine hemodialysis care, whereas group E patients received progressive intradialytic resistance exercise with high or moderate intensity for 12 weeks at three times per week (using the weight of the lower limbs and elastic ball movement of the upper limb) on the basis of routine hemodialysis care.

RESULTS

After 12 weeks, a significant difference in physical activity status (maximum grip strength, daily pace, and physical activity level), Kt/V, and C-reactive protein was found between groups E and C. Inflammatory factors (interleukin (IL)-6, IL-10, and tumor necrosis factor(TNF)-α) increased or decreased more significantly in group E than in group C.

CONCLUSIONS

This study showed that intradialytic resistance exercise can improve physical activity effectively and reduce microinflammatory reactions even if this simple exercise does not affect the muscle mass in MHD patients with sarcopenia.

Results from the randomized controlled IHOPE trial suggest no effects of oral protein supplementation and exercise training on physical function in hemodialysis patients

Few long-term studies have assessed whether changes in both diet and exercise can improve the health and quality of life (QOL) of hemodialysis (HD) patients. Here we examined whether 12 months of intradialytic protein supplementation and endurance exercise improves physical function, risk of cardiovascular disease (CVD), and QOL in HD patients in a randomized controlled trial (RCT). A total of 138 HD patients (average age 58 years) were assigned for 12 months to control, intradialytic protein, or protein plus exercise groups. The protein and protein plus exercise groups consumed an oral protein supplement (30 grams of whey) three days/week during dialysis. The protein plus exercise group cycled for 30-45 minutes during dialysis treatment. The primary outcome was change in physical function at 12 months, assessed by a shuttle walk test. Secondary outcomes included arterial stiffness, blood pressure, body composition, muscle strength, markers of nutritional status, and QOL. Assessments were conducted at baseline, 6 and 12 months. In total, 101 patients completed the intervention. There were no significant differences between groups in shuttle walk test performance from baseline to 12 months. There were trends for improvements in some secondary measures of physical function and strength in the protein and protein plus exercise groups at six or 12 months, but these did not reach statistical significance. Thus, our trial did not demonstrate significant improvements in markers of physical function, risk of CVD or QOL after one year of intradialytic oral OPS and aerobic exercise training. More comprehensive lifestyle management may be needed to uncover robust improvements in the health and QOL of HD patients.

The effects of oral nutritional supplements in patients with maintenance dialysis therapy: A systematic review and meta-analysis of randomized clinical trials

Background/objective

This systematic review aims to determine the potential effects of oral nutritional supplements (ONS) in patients receiving maintenance dialysis therapy (MDT).

Methods

Electronic databases were searched without language limits through to July 2018. Randomized controlled trials (RCTs) that involved comparisons of ONS versus placebo or routine care are included in this meta-analysis. RevMan 5.3 statistical software was used for meta-analysis.

Results

15 articles with 589 subjects were included in our study. There are insufficient comparable data of randomized trials to allow meta-analysis of mortality. Albumin levels may be improved by the macronutrient blends or protein/amino acid supplements in MDT patients. Compared with the control group, serum albumin levels and BMI in the ONS group were increased by 1.58 g/L (95% CI, 0.52–2.63, P = 0.003; I² = 85%) and 0.40 kg/m² (95% CI, 0.10–0.71, P = 0.01; I² = 49%), respectively. In the subgroup analysis of patients receiving hemodialysis, albumin levels in ONS group were increased by 2.17 g/L (95% CI, 0.89–3.45, P<0.001; I² = 90%). ONS may not influence serum phosphorus and potassium levels.

Conclusions

Very low-quality evidence suggests that Short-term oral energy or protein/amino acid supplements may improve nutritional status by increasing serum albumin levels and BMI in MDT patients, without influence on serum potassium levels. High-quality and large RCTs, particularly regarding the effects of ONS on mortality and quality of life, are needed to further validate our findings.

Pilot Study of the Effects of High-Protein Meals During Hemodialysis on Intradialytic Hypotension in Patients Undergoing Maintenance Hemodialysis

OBJECTIVE

Patients undergoing hemodialysis (HD) have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of HD treatment; but eating during HD may be discouraged because of concerns of postprandial hypotension. However, little data are available to support this practice. In this study, we hypothesized that high-protein meals during HD do not lead to symptomatic intradialytic hypotension events.

DESIGN

A 9-week, nonrandomized, parallel-arm study.

SETTING

A single in-center HD clinic.

SUBJECTS

Eighteen patients undergoing HD from 2 shifts completed the study. Patients were aged 62 ± 16 years with dialysis vintage of 3.4 ± 2.6 years.

INTERVENTION

Patients in the intervention group (n = 9) undergoing HD received meals of ∼30 g protein and ∼1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid during dialysis for 25 consecutive HD sessions. The control group (n = 9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions before the start of the intervention/control phase were used as a baseline comparison for each patient.

MAIN OUTCOME MEASURE

Symptomatic hypotension event frequency.

RESULTS

In the intervention arm, there were 19 symptomatic hypotension events in 5 patients prestudy and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients prestudy and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from prestudy to during study was not different between groups (P = .71). There was no effect of meals on nutritional status, but patients reported positive attitudes toward receiving meals during dialysis.

CONCLUSION

High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes.

Efficacy of Nutritional Interventions on Inflammatory Markers in Haemodialysis Patients: A Systematic Review and Limited Meta-Analysis

Low-grade chronic inflammation is prevalent in patients undergoing haemodialysis (HD) treatment and is linked to the development of premature atherosclerosis and mortality. The non-pharmacological approach to treat inflammation in HD patients through nutritional intervention is well cited. We aimed to assess the efficacy of different nutritional interventions at improving inflammatory outcomes in HD patients, based on markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). We searched PubMed, Cochrane Library, and Embase for randomized controlled trials (RCT) published before June 2017. Inclusion criteria included RCTs on adult patients on maintenance HD treatment with duration of nutritional interventions for a minimum 4 weeks. Risk of bias was assessed using the Jadad score. In total, 46 RCTs experimenting different nutritional interventions were included in the review and categorized into polyphenols rich foods, omega-3 fatty acids, antioxidants, vitamin D, fibres, and probiotics. Meta-analyses indicated significant reduction in CRP levels by omega-3 fatty acids (Random model effect: -0.667 mg/L, p < 0.001) and vitamin E (fixed model effect: -0.257 mg/L, p = 0.005). Evidence for other groups of nutritional interventions was inconclusive. In conclusion, our meta-analysis provided evidence that omega-3 fatty acids and vitamin E could improve inflammatory outcomes in HD patients.

The Impact of Hemodialysis on Spatio-Temporal Characteristics of Gait and Role of Exercise: A Systematic Review

Background: People with end-stage kidney disease (ESKD) on hemodialysis (HD) commonly have functional impairments. The purpose of this systematic review was to evaluate the effect of HD on spatio-temporal characteristics of gait, and effect of exercise on these parameters. Methods: Electronic databases were searched to identify relevant citations. Extracted data was computed using a random effects model for means (Hedges’ and 95% confidence interval (CI). Results: 27 studies met inclusion criteria. Mean values: gait speed (GS)—1.0 m/s (CI: 0.9–1.1 m/s; 16 studies), fast walking speed (FWS)—1.5 m/s (CI: 1.3–1.6 m/s; 7 studies), timed get-up & go test (TUG) —6.8 s (CI: 6.1–7.5 s; 2 studies), walk tests (WT) 193.0 s (CI: 116.0–270.0; 5 studies), 6 min-walk-test (6MWT)—386.6 m (CI: 243.2–530.0 m; 11 studies). 4 studies compared participants on HD with normal controls and 10 studies evaluated the effect of nutrition/exercise. Conclusions: Compared to age-matched populations, people with ESKD/HD had significantly slower GS and reduced walk distances; with intervention, the change in the distance walked was significant. Further research is required to evaluate the effect of HD on gait parameters, and the type of exercise/nutrition that will lead to meaningful changes.

Nutrient modulation in the management of disease-induced muscle wasting: evidence from human studies

PURPOSE OF REVIEW

In addition to being essential for movement, skeletal muscles act as both a store and source of key macronutrients. As such, muscle is an important tissue for whole body homeostasis, undergoing muscle wasting in times of starvation, disease, and stress, for example, to provide energy substrates for other tissues. Yet, muscle wasting is also associated with disability, comorbidities, and mortality. As nutrition is so crucial to maintaining muscle homeostasis 'in health', it has been postulated that muscle wasting in cachexia syndromes may be alleviated by nutritional interventions. This review will highlight recent work in this area in relation to muscle kinetics, the acute metabolic (e.g. dietary protein), and longer-term effects of dietary interventions.

RECENT FINDINGS

Whole body and skeletal muscle protein synthesis invariably exhibit deranged kinetics (favouring catabolism) in wasting states; further, many of these conditions harbour blunted anabolic responses to protein nutrition compared with healthy controls. These derangements underlie muscle wasting. Recent trials of essential amino acid and protein-based nutrition have shown some potential for therapeutic benefit.

SUMMARY

Nutritional modulation, particularly of dietary amino acids, may have benefits to prevent or attenuate disease-induced muscle wasting. Nonetheless, there remains a lack of recent studies exploring these key concepts to make conclusive recommendations.

Does whey protein supplementation affect blood pressure in hypoalbuminemic peritoneal dialysis patients?

Objective

Hypertension and hypoalbuminemia are common risk factors for cardiovascular complications in peritoneal dialysis (PD) patients. Data are limited regarding the effects of whey protein consumption on blood pressure in this population. The aim of the present study was to examine if whey protein supplementation for 12 weeks to hypoalbuminemic PD patients affects their blood pressure.

Patients and methods

This prospective randomized study included 36 stable PD patients with serum albumin levels <3.8 g/dL. During 12 weeks, 18 patients were instructed to consume 1.2 g/kg/day of protein and an additional whey protein supplement at a dose of 25% of the instructed daily protein (whey protein group). Eighteen patients were instructed to consume protein in the amount of 1.2 g/kg/day and an additional 25%, without whey protein supplementation (control group).

Results

Compared to the control group, in the whey protein group, serum albumin levels, oncotic pressure, and dialysate ultrafiltration significantly increased (3.55±0.14 to 4.08±0.15 g/dL, P<0.001; 21.81±2.03 to 24.06±1.54 mmHg, P<0.001; 927.8±120.3 to 1,125.0±125.1 mL/day, P<0.001; respectively) and were significantly higher after 12 weeks (4.08±0.15 vs 3.41±0.49 g/dL, P<0.001; 24.06±1.54 vs 22.71±1.77 mmHg, P=0.010; 1,125.0±125.1 vs 930.6±352.8 mL/day, P=0.017; respectively) in the whey protein group compared to the control group. Fluid overload, the extracellular to intracellular ratio and mean arterial pressure (MAP) significantly decreased (2.46±1.08 to 1.52±0.33, P<0.001; 1.080±0.142 to 0.954±0.124, P<0.001; 102.6±3.80 to 99.83±3.85, P=0.018; respectively) and were significantly lower in the whey protein group after 12 weeks (1.52±0.33 vs 2.23±0.73, P<0.001, 0.954±0.124 vs 1.048±0.111, P=0.002; 99.83±3.85 vs 102.8±3.93, P=0.018; respectively).

Conclusion

Whey protein supplementation for 12 weeks decreased MAP in hypoalbuminemic PD patients.

Does Whey Protein Supplementation Improve the Nutritional Status in Hypoalbuminemic Peritoneal Dialysis Patients?

Limited data are available regarding the effects of whey protein on the nutritional status of the peritoneal dialysis population. This study evaluated the effects of whey protein supplementation for 12 weeks on the nutritional status in hypoalbuminemic peritoneal dialysis patients. Thirty-six stable adult patients on maintenance peritoneal dialysis with serum albumin levels <3.5 g/dL were enrolled in the study and were divided into two groups similar in their serum albumin and normalized protein equivalent of total nitrogen appearance (nPNA). Nineteen patients were instructed to receive 1.2 g/kg per day of protein diet and additional whey protein supplement at a dose of 25% of the instructed daily protein diet (whey protein group), and 17 patients were instructed to receive 1.2 g/kg per day protein diet without additional whey protein supplementation (control group). Nutritional status was assessed using two measures: nPNA and lean tissue mass index (LTI) obtained by whole-body bioimpedance spectroscopy technique. In the whey protein group serum albumin and nPNA significantly increased from baseline to week 6 (P < 0.001, P = 0.034; respectively) and from week 6 to week 12 (P < 0.001, P = 0.001; respectively); LTI significantly increased from week 6 to week 12 (P = 0.022). Compared to the control group at week 12, serum albumin, nPNA and LTI values were significantly higher in the whey protein group (P < 0.001, P = 0.002, P = 0.001; respectively). This study demonstrated for the first time that oral supplementation with whey protein improves nutritional status and is well tolerated in hypoalbuminemic PD patients.

Longitudinal Associations among Renal Urea Clearance-Corrected Normalized Protein Catabolic Rate, Serum Albumin, and Mortality in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

There are inconsistent reports on the association of dietary protein intake with serum albumin and outcomes among patients on hemodialysis. Using a new normalized protein catabolic rate (nPCR) variable accounting for residual renal urea clearance, we hypothesized that higher baseline nPCR and rise in nPCR would be associated with higher serum albumin and better survival among incident hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Among 36,757 incident hemodialysis patients in a large United States dialysis organization, we examined baseline and change in renal urea clearance-corrected nPCR as a protein intake surrogate and modeled their associations with serum albumin and mortality over 5 years (1/2007-12/2011).

RESULTS

Median nPCRs with and without accounting for renal urea clearance at baseline were 0.94 and 0.78 g/kg per day, respectively (median within-patient difference, 0.14 [interquartile range, 0.07-0.23] g/kg per day). During a median follow-up period of 1.4 years, 8481 deaths were observed. Baseline renal urea clearance-corrected nPCR was associated with higher serum albumin and lower mortality in the fully adjusted model (Ptrend<0.001). Among 13,895 patients with available data, greater rise in renal urea clearance-corrected nPCR during the first 6 months was also associated with attaining high serum albumin (≥3.8 g/dl) and lower mortality (Ptrend<0.001); compared with the reference group (a change of 0.1-0.2 g/kg per day), odds and hazard ratios were 0.53 (95% confidence interval, 0.44 to 0.63) and 1.32 (95% confidence interval, 1.14 to 1.54), respectively, among patients with a change of <-0.2 g/kg per day and 1.62 (95% confidence interval, 1.35 to 1.96) and 0.76 (95% confidence interval, 0.64 to 0.90), respectively, among those with a change of ≥0.5 g/kg per day. Within a given category of nPCR without accounting for renal urea clearance, higher levels of renal urea clearance-corrected nPCR consistently showed lower mortality risk.

CONCLUSIONS

Among incident hemodialysis patients, higher dietary protein intake represented by nPCR and its changes over time appear to be associated with increased serum albumin levels and greater survival. nPCR may be underestimated when not accounting for renal urea clearance. Compared with the conventional nPCR, renal urea clearance-corrected nPCR may be a better marker of mortality.

The Diet and Haemodialysis Dyad: Three Eras, Four Open Questions and Four Paradoxes. A Narrative Review, Towards a Personalized, Patient-Centered Approach

The history of dialysis and diet can be viewed as a series of battles waged against potential threats to patients' lives. In the early years of dialysis, potassium was identified as "the killer", and the lists patients were given of forbidden foods included most plant-derived nourishment. As soon as dialysis became more efficient and survival increased, hyperphosphatemia, was identified as the enemy, generating an even longer list of banned aliments. Conversely, the "third era" finds us combating protein-energy wasting. This review discusses four questions and four paradoxes, regarding the diet-dialysis dyad: are the "magic numbers" of nutritional requirements (calories: 30-35 kcal/kg; proteins > 1.2 g/kg) still valid? Are the guidelines based on the metabolic needs of patients on "conventional" thrice-weekly bicarbonate dialysis applicable to different dialysis schedules, including daily dialysis or haemodiafiltration? The quantity of phosphate and potassium contained in processed and preserved foods may be significantly different from those in untreated foods: what are we eating? Is malnutrition one condition or a combination of conditions? The paradoxes: obesity is associated with higher survival in dialysis, losing weight is associated with mortality, but high BMI is a contraindication for kidney transplantation; it is difficult to limit phosphate intake when a patient is on a high-protein diet, such as the ones usually prescribed on dialysis; low serum albumin is associated with low dialysis efficiency and reduced survival, but on haemodiafiltration, high efficiency is coupled with albumin losses; banning plant derived food may limit consumption of "vascular healthy" food in a vulnerable population. Tailored approaches and agreed practices are needed so that we can identify attainable goals and pursue them in our fragile haemodialysis populations.

Beyond the Cholesterol-Lowering Effect of Soy Protein: A Review of the Effects of Dietary Soy and Its Constituents on Risk Factors for Cardiovascular Disease

The hypocholesterolemic effect of soy is well-documented and this has led to the regulatory approval of a health claim relating soy protein to a reduced risk of cardiovascular disease (CVD). However, soybeans contain additional components, such as isoflavones, lecithins, saponins and fiber that may improve cardiovascular health through independent mechanisms. This review summarizes the evidence on the cardiovascular benefits of non-protein soy components in relation to known CVD risk factors such as hypertension, hyperglycemia, inflammation, and obesity beyond cholesterol lowering. Overall, the available evidence suggests non-protein soy constituents improve markers of cardiovascular health; however, additional carefully designed studies are required to independently elucidate these effects. Further, work is also needed to clarify the role of isoflavone-metabolizing phenotype and gut microbiota composition on biological effect.