Etiology of the Protein-Energy Wasting Syndrome in Chronic Kidney Disease: A Consensus Statement From the International Society of Renal Nutrition and Metabolism (ISRNM)

Effect of Bariatric Surgery on Diagnosed Chronic Kidney Disease and Cardiovascular Events in Patients with Insulin-treated Type 2 Diabetes: a Retrospective Cohort Study from a Large UK Primary Care Database

Aims

To compare the effect of bariatric surgery on renal, chronic kidney disease (CKD) and cardiovascular (CV) outcomes among obese patients with insulin-treated type 2 diabetes (T2D) with and without microalbuminuria (i.e., uACR > 3.0 mg/mmol).

Methods

A retrospective cohort study was conducted among 11,125 active patients with T2D from The Health Improvement Network (THIN) database. Propensity score matching (up to 1:6 ratio) was used to identify patients who underwent bariatric surgery (N = 131) with a non-bariatric cohort (N = 579). Follow-up was undertaken for 10 years (6487 person-years) to compare differences in risk of cardiovascular events and in renal outcomes.

Results

For the matched cohort at baseline: mean age 52 ± 13 years (60% female); weight 116 ± 25 kg, body mass index (BMI) 41 ± 9kg/m², estimated glomerular filtration rate (eGFR); 70.4 ± 20 mL/min/1.73 m², and median albumin-creatinine ratio (uACR) 2.0 mg/mmol (interquartile range (IQR): 0.9–5.2 mg/mmol). Bariatric surgery was associated with a 54% reduction in developing CKD compared to their matched non-bariatric cohort (adjusted hazard ratio [aHR]: 0.46; 95%CI: 0.24–0.85, P = 0.02). Among patients with microalbuminuria at baseline, bariatric surgery was protective against CKD (aHR: 0.42, 95%CI: 0.18–0.99, P = 0.050). eGFR was significantly increased from baseline favouring the bariatric group during 75% of the follow-up time (calculated mean difference between groups: 4.1 mL/min/1.73 m²; P < 0.05), especially at 5-year point (74.2 vs 67.8 mL/min/1.73 m²; P < 0.001). However, no significant change was observed with non-fatal CVD episodes (aHR: 0.36, 95%CI: 0.11–1.13, P = 0.079). Albumin levels were significantly reduced throughout the 2 years following the surgery (3.9 vs 4.1 g/dL, P < 0.001). uACR and total protein levels had little or no statistical association to the intervention.

Conclusion

Bariatric surgery may protect patients with diabetes with or without microalbuminuria against the risk of CKD and with a modest protective effect on non-fatal CVD risk. Bariatric surgery is also associated with improvements in overall renal outcomes such as eGFR.

Significance of Levocarnitine Treatment in Dialysis Patients

Carnitine is a naturally occurring amino acid derivative that is involved in the transport of long-chain fatty acids to the mitochondrial matrix. There, these substrates undergo β-oxidation, producing energy. The major sources of carnitine are dietary intake, although carnitine is also endogenously synthesized in the liver and kidney. However, in patients on dialysis, serum carnitine levels progressively fall due to restricted dietary intake and deprivation of endogenous synthesis in the kidney. Furthermore, serum-free carnitine is removed by hemodialysis treatment because the molecular weight of carnitine is small (161 Da) and its protein binding rates are very low. Therefore, the dialysis procedure is a major cause of carnitine deficiency in patients undergoing hemodialysis. This deficiency may contribute to several clinical disorders in such patients. Symptoms of dialysis-related carnitine deficiency include erythropoiesis-stimulating agent-resistant anemia, myopathy, muscle weakness, and intradialytic muscle cramps and hypotension. However, levocarnitine administration might replenish the free carnitine and help to increase carnitine levels in muscle. This article reviews the previous research into levocarnitine therapy in patients on maintenance dialysis for the treatment of renal anemia, cardiac dysfunction, dyslipidemia, and muscle and dialytic symptoms, and it examines the efficacy of the therapeutic approach and related issues.

Optimal Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients with Sarcopenia: An Overview

Multi-factors, such as anorexia, activation of renin-angiotensin system, inflammation, and metabolic acidosis, contribute to malnutrition in chronic kidney disease (CKD) patients. Most of these factors, contributing to the progression of malnutrition, worsen as CKD progresses. Protein restriction, used as a treatment for CKD, can reduce the risk of CKD progression, but may worsen the sarcopenia, a syndrome characterized by a progressive and systemic loss of muscle mass and strength. The concomitant rate of sarcopenia is higher in CKD patients than in the general population. Sarcopenia is also associated with mortality risk in CKD patients. Thus, it is important to determine whether protein restriction should be continued or loosened in CKD patients with sarcopenia. We may prioritize protein restriction in CKD patients with a high risk of end-stage kidney disease (ESKD), classified to stage G4 to G5, but may loosen protein restriction in ESKD-low risk CKD stage G3 patients with proteinuria <0.5 g/day, and rate of eGFR decline <3.0 mL/min/1.73 m²/year. However, the effect of increasing protein intake alone without exercise therapy may be limited in CKD patients with sarcopenia. The combination of exercise therapy and increased protein intake is effective in improving muscle mass and strength in CKD patients with sarcopenia. In the case of loosening protein restriction, it is safe to avoid protein intake of more than 1.5 g/kgBW/day. In CKD patients with high risk in ESKD, 0.8 g/kgBW/day may be a critical point of protein intake.

Protein and energy intake: Comparison of two food services in patients during hemodialysis treatment

OBJECTIVES

Radboud University Medical Center introduced a new food service (NFS) to the hemodialysis (HD) department, which contains several small protein-rich foods and adheres to the Dutch dietary HD guidelines. The objectives were to investigate whether the NFS improves protein and energy intake compared with the old food service (OFS), the number of symptomatic hypotensive events (SHEs), and patient satisfaction.

METHODS

This was a prospective cohort (pilot) study of 25 adult patients with HD at the Radboud University Medical Center between August 2018 and February 2019. Differences in protein and energy intake over time by repeated measurements of the OFS and NFS were evaluated by linear mixed models with adjustments for confounders. SHEs, defined as a systolic drop >20 mmHg between two blood pressure measurements and 1) temporary or permanent stop ultrafiltration, 2) nausea, or 3) dizziness were collected. Patient satisfaction was determined by means of a self-developed questionnaire.

RESULTS

Protein and energy intake for the OFS and NFS differed significantly. Mean ± standard deviation for protein intake was 26 ± 11 g and 31 ± 13 g, respectively, and for energy intake 603 ± 218 kcal and 724 ± 244 kcal, respectively. No increase in SHEs occurred between the food services (2 SHEs at OFS vs 1 SHE at NFS). OFS patient satisfaction was graded 6.7 ± 2.3 and NFS was graded 7.3 ± 1.7.

CONCLUSIONS

NFS resulted in increased protein and energy intake and patient satisfaction, but no increase in SHEs was observed.

Validity and reliability of high-resolution ultrasound imaging for the assessment of regional body composition in stage 5 chronic kidney disease patients undergoing continuous ambulatory peritoneal dialysis

BACKGROUND

Accurate measurement of muscle mass is an important research and clinical tool. High-resolution ultrasound (US) has shown potential as a method to assess muscle and fat mass at specific anatomical sites. However, there is limited evidence for the reliability of US to measure muscle size in patients receiving continuous ambulatory peritoneal dialysis (CAPD). Therefore, we examined the validity and reliability of an US method compared to a gold standard comparison for the assessment of a quadriceps muscle in this clinical population.

METHODS

Twenty people receiving CAPD (mean age = 56.5 ± 16.7 years) at a single dialysis unit were assessed on two occasions, 7 days apart. Measures of the mid-thigh, such as vastus lateralis (VL) anatomical cross-sectional area (ACSA), VL muscle thickness and subcutaneous fat thickness were compared for US reliability and validity compared to magnetic resonance imaging (MRI) measures.

RESULTS

US had high validity against gold standard MRI measures, with intraclass correlation coefficients (ICC) equating to VL ACSA of 0.95, VL thickness of 0.99 and fat thickness of 0.98. The US measurements also exhibited high intra-rater reliability (ICCs: VL thickness = 0.98, total muscle thickness = 0.97 and fat thickness = 0.99) in measuring body composition at the mid-VL site in the study population.

CONCLUSIONS

Valid assessment of regional body composition can be achieved via high-resolution US in patients receiving CAPD. The validity and reliability of the US in repeated measures (in comparison to the gold standard MRI) warrant further investigation in the wider chronic kidney disease population.

Rapid Weight Change Over Time Is a Risk Factor for Adverse Outcomes in Patients With Predialysis Chronic Kidney Disease: A Prospective Cohort Study

OBJECTIVE

Both obesity and being underweight are risk factors for adverse outcomes in chronic kidney disease (CKD) patients. However, the effects of longitudinal weight changes on patients with predialysis CKD have not yet been studied. In this study, we analyzed the effects of weight change over time on the adverse outcomes in predialysis CKD population.

METHODS

Longitudinal data from a multicenter prospective cohort study (KNOW-CKD) were analyzed. In a total of 2,022 patients, the percent weight change per year were calculated using regression analysis and the study subjects were classified into five categories: group 1, ≤ -5%/year; group 2, -5< to ≤ -2.5%/year; group 3, -2.5< to <2.5%/year; group 4, 2.5≤ < 5%/year; and group 5, ≥5%/year. The incidences of end-stage renal disease (ESRD) and the composite outcome of cardiovascular disease (CVD) and death were calculated in each group and compared to group 3 as reference.

RESULTS

During a median 4.4 years of follow-up, 414 ESRD, and 188 composite of CVD and mortality events occurred. Both weight gain and loss were independent risk factors for adverse outcomes. There was a U-shaped correlation between the degree of longitudinal weight change and ESRD (hazard ratio 3.61, 2.15, 1.86 and 3.66, for group 1, 2, 4 and 5, respectively) and composite of CVD and death (hazard ratio 2.92, 2.15, 1.73 and 2.54, respectively), when compared to the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m².

CONCLUSION

Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in the advanced CKD.

Prevalence and Associated Factors of Frailty and Mortality in Patients with End-Stage Renal Disease Undergoing Hemodialysis: A Systematic Review and Meta-Analysis

Hemodialysis is the most common type of treatment for end-stage renal disease (ESRD). Frailty is associated with poor outcomes such as higher mortality. ESRD patients have a higher prevalence of frailty. This systematic review and meta-analysis aimed to identify the prevalence and associated factors of frailty and examine whether it is a predictor of mortality among ESRD patients undergoing hemodialysis. Five electronic databases including PubMed, Embase, CINAHL, Web of Science, and Cochrane Library were searched for relevant studies up to 30 November 2020. A total of 752 articles were found, and seven studies with 2604 participants in total were included in the final analysis. The pooled prevalence of frailty in patients with ESRD undergoing hemodialysis was 46% (95% Confidence interval (CI) 34.2−58.3%). Advanced age, female sex, and the presence of diabetes mellitus increased the risk of frailty in ESRD patients undergoing hemodialysis. Our main finding showed that patients with frailty had a greater risk of all-cause mortality compared with those without (hazard ratio (HR): 2.02, 95% CI: 1.65−2.48). To improve ESRD patient outcomes, healthcare professionals need to assess the frailty of older ESRD patients, particularly by considering gender and comorbidities. Comprehensive frailty screening tools for ESRD patients on hemodialysis need to be developed.

Hand Grip and Leg Muscle Strength in Hemodialysis Patients and Its Determinants

BACKGROUND

Chronic kidney disease is associated with chronic inflammation and progressive loss of peripheral muscle strength and the ability to exercise, and these changes are highly pronounced in patients receiving hemodialysis (HD). We evaluated hand grip strength (HGS) and leg muscle strength (LMS) in patients receiving HD and attempted to identify factors associated with muscle strength.

METHODS

We screened HGS (opposite the fistula side) and LMS (both sides) in HD patients at a single center (n = 112) by using digital hand and leg dynamometers (T.K.K. 5401 and 5710e/5715, Takei Scientific Instruments Co. Ltd., Niigata, Japan).

RESULTS

The mean age of patients was 62.6 years, and 73.2% of the patients were male. Diabetes was the cause of kidney failure in 50% of the patients, and the median HD vintage was 34 months. A total of 77.7% of patients reported that they participated in regular home-based exercise, and 29.5% of patients regularly participated in hospital-based resistance exercise. HGS and LMS showed good correlation (r = 0.715, P < 0.001). HGS (25.1 vs. 17.0 kg) and LMS (30.1 vs. 20.4 kg) were greater in males (P < 0.001 and P < 0.001, respectively) than in females. Older patients (≥ 60 years) showed less LMS than younger patients in both males and females (P = 0.012 and P = 0.037, respectively), but HGS did not differ according to age. Patients performing regular home- or hospital-based exercise showed higher HGS than those who did not exercise (24.2 vs. 18.6 kg, P = 0.011), but LMS was not significantly different (29.3 vs. 23.6 kg, P = 0.185). Multiple linear regression analysis proved that male sex, younger age, and any type of exercise were factors associated with improved HGS and LMS. Groups of older age (≥ 60 years), male sex, and shorter duration of HD (< median) benefitted more from exercise.

CONCLUSION

Sex, age, and exercise were the most important determinants of muscle strength in HD patients. We need to encourage patients to engage in regular home or group exercise from the beginning of dialysis and introduce new feasible forms of exercise for HD patients.

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.

Vitamin D and skeletal muscle: A narrative review focusing on chronic kidney disease and dialysis

Morphological, molecular, and physiological effects of vitamin D on skeletal muscle have been analyzed both in animals and humans. Vitamin D may be a potential therapeutic for increasing muscle mass and function. The presence of vitamin D receptors in skeletal muscle cells is already established. However, there is still need for more evidence about the effect of vitamin D on muscle. Some studies have associated vitamin D and skeletal muscle in chronic kidney disease (CKD) patients; most of these studies enrolled hemodialysis patients. FGF-23 and Klotho were recently described in mineral and bone disorders in CKD, resulting in reductions in calcitriol levels. Therefore, both Klotho and FGF-23 may play a role in muscle loss in CKD, which is related to morbidity and mortality risk. Therefore, this article presents a narrative review, aiming to discuss the available information associating skeletal muscle and vitamin D, highlighting the results in CKD and dialysis patients.

Thyroid hormone status in patients with impaired kidney function

PURPOSE

We aimed to investigate the prevalence of thyroid hormone abnormalities and the relationship between free triiodothyronine (fT3), thyroid stimulating hormone (TSH) and free thyroxine (fT4) serum levels with kidney function and proteinuria in 4108 subsequent patients admitted to a Nephrology Clinic at a tertiary Medical Centre.

METHODS

All patients were categorized based on their estimated glomerular filtration rate (eGFR) as follows: normal-eGFR ≥ 60 ml/min, mild kidney impairment-30 ≤ eGFR < 60 ml/min, and severe kidney impairment-eGFR < 30 ml/min.

RESULTS

Subjects with normal eGFR presented a laboratory constellation of hypothyroidism in 3.38% and "low-T3 syndrome" in 8.28%, while subjects with severe kidney impairment were diagnosed with hypothyroidism in 2.82% and "low-T3 syndrome" in 22.9%. Multivariate regression analysis showed that eGFR was a strong independent predictor of serum fT3 levels in patients with eGFR < 60 ml/min. Impaired kidney function was associated with low fT4 and fT3 but not TSH. Our findings showed an inverse correlation of fT3 and fT4 levels and proteinuria range. FT4 inversely correlated with the extent of proteinuria in all subgroups of patients. In contrast, the inverse correlation of fT3 serum levels and proteinuria disappeared in patients with eGFR < 60 ml/min.

CONCLUSION

In a large cohort of inpatients, the prevalence of low-T3 syndrome was 2.5 times higher in patients with advanced kidney disease, compared to those with normal kidney function. In advanced CKD, both eGFR and proteinuria were strongly correlated with thyroid hormones. Therefore, close screening of the "thyroid profile" in patients with any stage of CKD, especially to those with proteinuria, might be warranted.

The long-term prognostic factors in hemodialysis patients with acute coronary syndrome: perspectives from sarcopenia and malnutrition

Hemodialysis (HD) patients tend to have sarcopenia and malnutrition, and both conditions are related to poor prognosis in the cardiovascular disease that often accompanies HD. However, the impact of sarcopenia or malnutrition on the long-term prognosis of HD patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) remains unclear. We analyzed 1,605 consecutive patients with ACS who had undergone PCI at a single center between January 2009 and December 2014. We evaluated all-cause mortality and prognosis-associated factors, including sarcopenia/malnutrition-related factors such as the Geriatric Nutritional Risk Index (GNRI), and Skeletal Muscle Mass Index (SMI). After exclusions, 1461 patients were enrolled, and 58 (4.0%) were on HD. The HD group had lower levels of SMI and GNRI than non-HD group, and had worse in-hospital prognosis. Moreover, HD group had a significant higher mortality in the long-term follow-up [median follow-up period: 1219 days; Hazard Ratio (HR) = 4.09, p < 0.001]. After adjusting the covariates, SMI and GNRI were the factors associated with all-cause mortality in all patients [SMI: adjusted HR (aHR) = 2.39, p = 0.036; GNRI: aHR = 2.21, p = 0.006]; however, these findings were not observed among HD patients with ACS, and only diabetes was significantly associated with all-cause mortality (diabetes: aHR = 3.50, p = 0.031). HD patients with ACS had a significantly higher rate of in-hospital and long-term mortality than non-HD patients. Although sarcopenia and malnutrition were related to mortality and were more common in HD patients, sarcopenia and malnutrition had a lower impact than diabetes on the long-term prognosis of HD patients with ACS.

Frequency of Intradialytic Hypotension Events Do Not Increase with Oral Nutritional Supplementation during Hemodialysis Treatment: A Randomized Controlled Trial

OBJECTIVE

This study aimed to compare the effect of the use of a renal-specific oral nutritional supplement (RS-ONS) during hemodialysis sessions and the use of RS-ONS at home on the incidence of intradialytic hypotension.

METHODS

A single-center, 12-week, open-label, randomized controlled clinical trial was conducted. The intervention was a RN-ONS divided into two portions: 100 and 137 mL. The first portion was given after 1 hour of hemodialysis (HD) treatment, while the second portion was given 45 minutes before the end of HD. The research staff registered the baseline and final nutritional parameters and systolic arterial pressure (SAP) from the screen of the HD device during 36 HD sessions. Hypotension symptoms were also recorded every hour during each HD session. The nutritional and functional status was also assessed.

RESULTS

We registered a total of 16 hypotensive events during 1082 HD sessions: 9 were in patients supplemented at home (551 HD sessions) and 7 occurred in patients supplemented during HD P = .668. Incidence of intradialytic hypotension (IH) during 1082 HD sessions was 1.4%. The total malnutrition inflammation score (MIS) decreased in both groups (P < .01), and the percentage of cachexia improved in the supplemented-during-HD group (P < .05).

CONCLUSIONS

In this randomized controlled trial, intradialytic hypotension events did not increase with the RS-ONS during HD treatment. This strategy appears to be a safe anabolic nutritional strategy for the prevention of PEW, selecting stable patients and administering a fractioned volume of the supplement after the first hour of HD treatment. More studies with larger samples size are required to confirm these findings.

Dietary intake in adults on hemodialysis compared with guideline recommendations

Background

Clinical practice guidelines of dietary management are designed to promote a balanced diet and maintain health in patients undergoing haemodialysis but they may not reflect patients’ preferences. We aimed to investigate the consistency between the dietary intake of patients on maintenance haemodialysis and guideline recommendations.

Methods

Cross-sectional analysis of the DIET-HD study, which included 6,906 adults undergoing haemodialysis in 10 European countries. Dietary intake was determined using the Global Allergy and Asthma European Network (GA²LEN) Food Frequency Questionnaire (FFQ), and compared with the European Best Practice Guidelines. Consistency with guidelines was defined as achieving the minimum daily recommended intake for energy (≥ 30 kcal/kg) and protein (≥ 1.1 g/kg), and not exceeding the maximum recommended daily intake for phosphate (≤ 1000 mg), potassium (≤ 2730 mg), sodium (≤ 2300 mg) and calcium (≤ 800 mg).

Results

Overall, patients’ dietary intakes of phosphate and potassium were infrequently consistent with guidelines (consistent in 25% and 25% of patients, respectively). Almost half of the patients reported that energy (45%) and calcium intake (53%) was consistent with the guidelines, while the recommended intake of sodium and protein was consistent in 85% and 67% of patients, respectively. Results were similar across all participating countries. Intake was consistent with all six guideline recommendations in only 1% of patients.

Conclusion

Patients on maintenance haemodialysis usually have a dietary intake which is inconsistent with current recommendations, especially for phosphate and potassium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-020-00962-3.

Exploring the experiences and perceptions of haemodialysis patients observing Ramadan fasting: a qualitative study

BACKGROUND

The festival of Ramadan is a month of spiritual reflection for Muslims worldwide. During Ramadan, Muslims are required to refrain from eating and drinking during daylight hours. Although exempted from fasting, many patients undergoing maintenance haemodialysis (HD) opt to participate in this religious practice. Many studies have explored the effects of Ramadan on health outcomes, however, the exploration from patients' own point of view pertaining to this religious practice is lacking. Thus, we aimed to explore the experiences and perceptions of Muslim HD patients observing Ramadan fasting from three HD centres in Klang Valley, Malaysia.

METHOD

An exploratory phenomenology qualitative study was conducted whereby subjects were purposively selected based on previous experience in observing Ramadan fasting. Face-to-face in-depth interviews were conducted, and study data were analyzed thematically and iteratively coded using a constant comparison method.

RESULTS

Four major themes emerged from the data, namely: (i) "fasting experiences", (ii) "perceived side effects of fasting", (iii) "health-seeking behavior" and, (iv) "education and awareness needs". Patients expressed the significance of Ramadan fasting as well as the perceived impact of fasting on their health. Additionally, there is lack of health-seeking behaviour observed among patients thus, raising needs for awareness and education related to Ramadan fasting.

CONCLUSIONS

Findings of this study shed light on patients' experiences and perceptions regarding Ramadan fasting which warrants the needs for an effective communication between patients and health care practitioners through a structured-Ramadan specific education program.

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.

Uremic Sarcopenia and Its Possible Nutritional Approach

Uremic sarcopenia is a frequent condition present in chronic kidney disease (CKD) patients and is characterized by reduced muscle mass, muscle strength and physical performance. Uremic sarcopenia is related to an increased risk of hospitalization and all-causes mortality. This pathological condition is caused not only by advanced age but also by others factors typical of CKD patients such as metabolic acidosis, hemodialysis therapy, low-grade inflammatory status and inadequate protein-energy intake. Currently, treatments available to ameliorate uremic sarcopenia include nutritional therapy (oral nutritional supplement, inter/intradialytic parenteral nutrition, enteral nutrition, high protein and fiber diet and percutaneous endoscopic gastrectomy) and a personalized program of physical activity. The aim of this review is to analyze the possible benefits induced by nutritional therapy alone or in combination with a personalized program of physical activity, on onset and/or progression of uremic sarcopenia.

Dietary protein interventions to improve nutritional status in end-stage renal disease patients undergoing hemodialysis

PURPOSE OF REVIEW

Poor nutritional status is prevalent among end-stage renal disease patients undergoing hemodialysis. Chronic hemodialysis patients show an accelerated decline in skeletal muscle mass and strength, which is associated with higher mortality rates and a reduced quality of life. The current review aims to summarize recent advances regarding underlying causes of muscle loss and interventions that support muscle mass maintenance in patients with chronic hemodialysis.

RECENT FINDINGS

Muscle maintenance in chronic hemodialysis patients is compromised by low dietary protein intake levels, anabolic resistance of skeletal muscle tissue, sedentary behavior, and amino acid removal during hemodialysis. Studies assessing the effect of increased protein intake on nutritional status generally show beneficial results, especially in hypoalbuminemic chronic hemodialysis patients. The muscle protein synthetic response following protein ingestion in chronic hemodialysis patients may be enhanced through incorporation of structured physical activity and/or concurrent ketoacid ingestion.

SUMMARY

A coordinated program that combines nutritional and physical activity interventions is likely required to attenuate the decline in muscle mass and strength of chronic hemodialysis patients. Nephrologists, dieticians, and exercise specialists should collaborate closely to establish guidelines regarding the appropriate quantity and timing of protein ingestion. In addition, they should provide tailored nutritional and physical activity interventions for chronic hemodialysis patients (see video, Supplemental Digital Content 1, Video abstract, http://links.lww.com/COCN/A14).

Renal and Hepatic Disease: Cnidoscolus aconitifolius as Diet Therapy Proposal for Prevention and Treatment

The lack of prevention of noncommunicable diseases (NCDs) has caused an increase in the mortality rate including conditions such as chronic kidney disease (CKD) and liver disease (LD). The high complexity of CKD and LD results in alterations in the metabolism of carbohydrates, proteins, and lipids. One of the changes observed in CKD and LD is the decrease in albumin, elevation of PO₄^-3, K⁺, creatinine, urea, and transaminase enzymes. The pharmacological treatment is expensive. Nowadays, phytotherapy is an option to treat NCDs. Aqueous, ethanolic, methanolic, and ethyl acetate extracts of Cnidoscolus aconitifolius have shown nephroprotective and hepatoprotective potential and can be an alternative to prevent and treat CKD and LD. C. aconitifolius, known as Chaya by Mayas in Yucatán, is a shrub that is consumed in Mexico and in the world, has a low cost, it is very accessible, and can growth in extreme weather. The aim of this review is to show the potential biological effects of C. aconitifolius extracts, and the association of the phytochemicals in the extract. It is known that different solvents result in the uptake of different phytochemicals. These have shown various effects such as hypoglycemic, hypotensive, hypolipidemic, and antioxidant, being a natural alternative to the treatment of NCDs.Key teaching pointsPhytotherapy is a proposal to treat NCDs.Cnidoscolus aconitifolius extracts have a hypotensive effect.Cnidoscolus aconitifolius extracts reduce blood sugar in diabetic rats.Chaya extracts are no toxic for renal and hepatic cells.

The Aryl Hydrocarbon Receptor in Chronic Kidney Disease: Friend or Foe?

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that promotes cell responses to small molecules derived from the diet, microorganisms, metabolism and pollutants. The AhR signal regulates many basic cellular processes, including cell cycle progression, adhesion, migration, apoptosis and cell proliferation. Many studies have shown that AhR is associated with chronic kidney disease (CKD) and its complications. This article reviews the current knowledge about the role of AhR in CKD, showing that AhR mediates CKD complications, including cardiovascular disease, anemia, bone disorders, cognitive dysfunction and malnutrition, and that it influences drug metabolism in individuals with CKD. AhR enhances the intestinal barrier function to reduce the harmful effects of uremic toxins. Therefore, understanding the complex roles of AhR during CKD is important to be able to target this transcription factor safely and effectively for CKD prevention and treatment.

Prevalence of malnutrition inflammation complex syndrome among patients on maintenance haemodialysis at Muhimbili National Hospital in Tanzania: a cross-sectional study

Background

Malnutrition, inflammation, and the combination thereof are predictors of poor outcomes in haemodialysis patients. Malnutrition Inflammation Complex Syndrome (MICS) is an accelerator of atherosclerosis and portends high mortality. Early recognition and treatment of MICS may help to improve the clinical outlook of such patients. This study investigated the prevalence of MICS and its associated factors among patients on maintenance haemodialysis at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania.

Methods

This was a prospective cross-sectional observational study done among 160 adult patients on maintenance haemodialysis at MNH in 2019. All participants provided written informed consent. Questionnaires were used to collect data and patients’ blood was tested for complete blood count (CBC), C-reactive protein (CRP), ferritin, transferrin, creatinine, urea, total cholesterol, and albumin. The Malnutrition Inflammation Score was used to assess MICS and its severity. Data analysis was done using the SPSS 20 software.

Results

Of the 160 patients included in the study, 111 (69.4%) were male. The mean age (±SD) of patients and mean duration (±SD) on haemodialysis were 52.2(13.3) years and 22(18) months respectively. MICS was prevalent in 46.3% (mild in 24.4% and moderate to severe in 21.9%).

Long-term haemodialysis (> 4 years) was an independent predictor of MICS [Adjusted Odds Ratio, AOR 5.04 (95% CI: 1.33–19.2), p < 0.05]. Hypercholesterolaemia was a negative predictor of MICS [AOR 0.11 (95% CI: 0.01–0.97), p < 0.05]. Patients with MICS had significantly lower mean body mass index, serum albumin, total cholesterol, transferrin, haemoglobin, and creatinine levels. The presence of MICS was higher in underweight patients and those who had inflammation. Haemodialysis adequacy did not correlate with MICS.

Conclusion

Malnutrition Inflammation Complex Syndrome is relatively common among patients on haemodialysis in Dar es Salaam, Tanzania. Our study has shown a longer duration on haemodialysis to be associated with the occurrence of MICS; on the contrary, having hypercholesterolaemia seems to be protective against MICS consistent with the concept of reverse epidemiology. Patients on haemodialysis should be assessed regularly for malnutrition and inflammation and should receive appropriate and timely treatment to reduce the burden of associated morbidity, and mortality to these patients.

Medical Nutritional Therapy for Patients with Chronic Kidney Disease not on Dialysis: The Low Protein Diet as a Medication

The 2020 Kidney Disease Outcome Quality Initiative (KDOQI) Clinical Practice Guideline for Nutrition in chronic kidney disease (CKD) recommends protein restriction to patients affected by CKD in stages 3 to 5 (not on dialysis), provided that they are metabolically stable, with the goal to delay kidney failure (graded as evidence level 1A) and improve quality of life (graded as evidence level 2C). Despite these strong statements, low protein diets (LPDs) are not prescribed by many nephrologists worldwide. In this review, we challenge the view of protein restriction as an "option" in the management of patients with CKD, and defend it as a core element of care. We argue that LPDs need to be tailored and patient-centered to ensure adherence, efficacy, and safety. Nephrologists, aligned with renal dietitians, may approach the implementation of LPDs similarly to a drug prescription, considering its indications, contra-indications, mechanism of action, dosages, unwanted side effects, and special warnings. Following this framework, we discuss herein the benefits and potential harms of LPDs as a cornerstone in CKD management.

Effects of long-term intradialytic oral nutrition and exercise on muscle protein homeostasis and markers of mitochondrial content in patients on hemodialysis

Patients with end-stage kidney disease on maintenance hemodialysis commonly develop protein-energy wasting, a syndrome characterized by nutritional and metabolic abnormalities. Nutritional supplementation and exercise are recommended to prevent protein-energy wasting. In a 6-mo prospective randomized, open-label, clinical trial, we reported that the combination of resistance exercise and nutritional supplementation does not have an additive effect on lean body mass measured by dual-energy X-ray absorptiometry. To provide more mechanistic data, we performed a secondary analysis where we hypothesized that the combination of nutritional supplementation and resistance exercise would have additive effects on muscle protein accretion by stable isotope protein kinetic experiments, muscle mass by MRI, and mitochondrial content markers in muscle. We found that 6 mo of nutritional supplementation during hemodialysis increased muscle protein net balance [baseline: 2.5 (-17.8, 13.0) µg·100 mL-1·min-1 vs. 6 mo: 43.7 (13.0, 98.5) µg·100 mL-1·min-1, median (interquartile range), P = 0.04] and mid-thigh fat area [baseline: 162.3 (104.7, 226.6) cm2 vs. 6 mo: 181.9 (126.3, 279.2) cm2, median (interquartile range), P = 0.04]. Three months of nutritional supplementation also increased markers of mitochondrial content in muscle. Although the study is underpowered to detected differences, the combination of nutritional supplementation and exercise failed to show further benefit in protein accretion or muscle cross-sectional area. We conclude that long-term nutritional supplementation increases the skeletal muscle anabolic effect, the fat cross-sectional area of the thigh, and markers of mitochondrial content in skeletal muscle.

Bioelectrical impedance analysis-derived phase angle as a determinant of protein-energy wasting and frailty in maintenance hemodialysis patients: retrospective cohort study

Background

Phase angle (PA), measured by bioelectrical impedance analysis (BIA) has been studied as indicator of nutritional status or muscle function in hemodialysis (HD) patients. It remains unclear if the phase angle is associated protein-energy wasting (PEW) or frailty, which are common complication in hemodialysis patients. The aim of this study is to determine whether BIA-derived PA is a marker of PEW or frailty in HD patients.

Methods

This retrospective observational study included 116 adult HD patients (35% female, 64 ± 12 years of age) in a single dialysis center. Patients were classified according to the PA quartiles into four groups; 1) first quartile: PA < 3.7°, 2) second quartile: PA 3.7–4.1°, 3) third quartile: PA 4.2–4.9°and 4) forth quartile: PA ≥ 5.0°. International Society of Renal Nutrition and Metabolism (ISRNM) criteria and Japanese version of Cardiovascular Health Study (J-CHS) criteria were used to identify PEW and frailty.

Results

The lower PA group was associated with a greater risk of PEW (35% vs. 24% vs. 21% vs. 3%; p = 0.032), frailty (59% vs. 40% vs. 21% vs. 3%; p < 0.001). In multivariate logistic regression analysis, the first quartile group was at a significantly greater risk of both PEW and frailty compared with the fourth quartile group after adjusting for other confounding factors.

Conclusions

Lower PA was associated with a greater risk of PEW and frailty in HD patients.

Understanding Development of Malnutrition in Hemodialysis Patients: A Narrative Review

Hemodialysis (HD) majorly represents the global treatment option for patients with chronic kidney disease stage 5, and, despite advances in dialysis technology, these patients face a high risk of morbidity and mortality from malnutrition. We aimed to provide a novel view that malnutrition susceptibility in the global HD community is either or both of iatrogenic and of non-iatrogenic origins. This categorization of malnutrition origin clearly describes the role of each factor in contributing to malnutrition. Low dialysis adequacy resulting in uremia and metabolic acidosis and dialysis membranes and techniques, which incur greater amino-acid losses, are identified modifiable iatrogenic factors of malnutrition. Dietary inadequacy as per suboptimal energy and protein intakes due to poor appetite status, low diet quality, high diet monotony index, and/or psychosocial and financial barriers are modifiable non-iatrogenic factors implicated in malnutrition in these patients. These factors should be included in a comprehensive nutritional assessment for malnutrition risk. Leveraging the point of origin of malnutrition in dialysis patients is crucial for healthcare practitioners to enable personalized patient care, as well as determine country-specific malnutrition treatment strategies.

Assessment of nutritional status in maintenance hemodialysis patients: A multicenter cross-sectional study in Iran

INTRODUCTION

Protein-energy wasting (PEW) is common in hemodialysis patients and is linked with a high rate of morbidity and mortality. Regarding importance of nutrition in these patients, a recent study was administered to evaluate the nutritional status of hemodialysis patients.

MATERIALS

In this cross-sectional study 540 HD patients from 15 dialysis centers were evaluated. The nutritional status of the patients was determined by Subjective Global Assessment (SGA), Dialysis Malnutrition Score (DMS), and Malnutrition Inflammation Score (MIS). Their dietary intakes were assessed using a Food Frequency Questionnaire (FFQ).

RESULT

Based on DMS, 66.7% of HD patients were well nourished and the prevalence of mild-to-moderate and severe PEW were 32.4% and 0.9% in HD patients, respectively. Based on MIS, 65.2% of HD patients were well nourished and the prevalence of mild-to-moderate and severe PEW was 34.0%. The prevalence of mild-to-moderate and severe malnutrition based on SGA was 35.0% and 1.1%, respectively. Energy and protein intake in 85.6% and 80.6% of patients respectively were less than the minimum recommended amount.

CONCLUSION

HD patients are at risk of malnutrition and in this regard training the patient, periodic assessment of nutritional status, and referring them to a dietitian seems necessary.

A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed

Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.

Handgrip strength as an instrument for assessing the risk of malnutrition and inflammation in hemodialysis patients

INDRODUCTION

Establishing which parameters to use for diagnosing malnutrition in hemodialysis patients is a challenge in clinical practice. The handgrip strength (HGS) has stood out as a method of assessing nutritional status. Thus, the aim of this study was to determine the cut-off point for HGS in the assessment of the risk of malnutrition and inflammation in HD patients, and its association with other parameters.

METHODS

Study carried out in hemodialysis units in the city of Curitiba, Brazil. We obtained the cut-off point of the HGS through the ROC curve, using the malnutrition and inflammation score (MIS) as a reference. We checked the relationship (Odds ratio) between the variables "MIS" and "HGS" with the other study variables using the multivariate analysis (logistic regression).

RESULTS

We assessed 238 patients (132 men), between 18 and 87 years of age (median = 59). The HGS cut-off point for diagnosing malnutrition and inflammation according to the reference used was <14.5 kg for women, and <23.5 kg for men. According to the HGS criteria, malnourished patients were older (OR = 0.958), with lower arm circumference (OR = 1.328) and higher scores in the malnutrition and inflammation score (OR = 0.85).

CONCLUSION

HGS was significantly correlated with other nutritional assessment parameters. These results suggest that HGS is a valid screening tool to identify the risk of malnutrition and inflammation in hemodialysis patients.

Physical Activity versus Sclerostin and Interleukin 6 Concentration in Patients Receiving Renal Replacement Therapy by Hemodialysis

Introduction

Chronic kidney disease and renal replacement therapy are associated with reduced motor activity, which may result in the presence of mineral bone disorders and an increase in inflammation markers. The aim of the study was to assess the relationship between the performance of daily physical activity, expressed in the number of steps performed by patients undergoing hemodialysis and the concentration of selected biochemical parameters (SCL, IL-6).

Patients and Methods

The study group (B) involved 33 patients aged 59.8 ± 9.8 years from the dialysis station at the Department of Nephrology, Transplantology and Internal Medicine PUM. In group B, interventions considering an increase in physical activity expressed in the number of steps were introduced. Group C consisted of 30 people aged 54.9 (9.37), with GFR over 60 mL/min/1.73m. Physical activity was measured with pedometers. Anthropometric and biochemical parameters were assessed at baseline, after the third and sixth month of the study. Descriptive statistics, intergroup comparisons using Mann–Whitney U test and Spearman correlation analysis were performed. The level of significance was set at p≤0.005.

Results

A relationship between IL-6 concentration and the number of steps in group B after three months of intervention was demonstrated. In group C, the concentration of SCL and IL-6 decreased with the increase in the number of steps taken. Only in group C the waist circumference decreased with the increase of the number of steps performed.

Conclusion

Patients receiving renal replacement therapy by hemodialysis showed significantly lower physical activity compared to people without kidney disease. Performing bigger number of steps can lower interleukin 6 levels in hemodialysis patients.

Protein Energy Wasting in Children With Chronic Kidney Disease and End-Stage Kidney Disease: An Observational Study

OBJECTIVES

Protein energy wasting (PEW), a specific nutritional comorbidity associated with increased mortality, is underrecognized in children with chronic kidney disease (CKD). The aim of this study was to determine the burden and factors associated with PEW and assess the utility of parameters used to diagnose PEW in children with CKD and End stage kidney disease (ESKD).

METHODS

Children between 2 and 18 years of age with CKD stages 2-5 were recruited over 30 months. Parameters of PEW assessed included body mass index for height, mid-upper arm circumference, height for age, appetite, serum albumin, cholesterol, transferrin, and C-reactive protein. Based on number of criteria fulfilled in each subject, PEW was further stratified as mild, standard, and modified PEW.

RESULTS

One hundred twenty-three children (male:female 3:1, 73 in CKD stages 2-4, 50 with ESKD) were recruited. PEW was observed in 58% (47% in CKD stages 2-4 vs. 73% ESKD, P = .035). Longer duration and severity of disease was associated PEW. Reduced appetite (P = .001, P = .04), low mid-upper arm circumference (P = .000, P = .006), and low body mass index for height (P = .000, P = .007) were useful criteria to diagnose PEW in CKD stages 2-4 and ESKD, while most children did not meet biochemical criteria. Inflammation observed in 47% was higher in those with ESKD [CKD stages 2-4: 72 (39%) vs. ESKD: 29 (59%), P = .02] but was associated with PEW only in CKD stages 2-4.

CONCLUSION

PEW was highly prevalent in children with CKD and ESKD. Appetite and anthropometry measures were more useful than biochemical criteria for diagnosis of PEW. Whereas inflammation was common, it was associated with PEW only in CKD stages 2-4. Pediatric CKD and ESKD may need exclusive diagnostic criteria for PEW based on anthropometry, appetite, and inflammation.

Dietary Inflammatory Index Is a Better Determinant of Quality of Life Compared to Obesity Status in Patients With Hemodialysis

OBJECTIVES

This study aimed to investigate the relationships among obesity, anthropometries, and the dietary inflammatory index (DII) with different aspects of quality of life (QoL) in patients undergoing hemodialysis.

DESIGN AND METHODS

In 83 patients representing a range of body weights, QoL (based on short form 36), DII (extracted from dietary recalls), malnutrition-inflammation score, and anthropometric measurements were assessed.

RESULTS

Obese patients had lower physical health score (mean difference [MD] 9.1, 95% confidence interval [CI] 0.3-17.8, P = .04), physical functioning (MD 10.5, 95% CI 0.7-20.2, P = .04), and bodily pain scores (MD 16.0, 95% CI 3.6-28.4, P = .01) than normal weight group. Patients with abdominal obesity and those with the highest body fat percentage had also lower QoL in many aspects, irrespective of body mass index. The physical (MD 13.2, 95% CI 2.05-24.3, P = .02) and mental (MD 18.4, 95% CI 7.51-29.2, P = .001) health scores, and physical functioning (MD 13.5, 95% CI 1.8-25.2, P = .02), role-physical (MD 25.8, 95% CI 3.0-48.6, P = .03), role-emotional (MD 22.1, 95% CI 5.4-52.8, P = .02), vitality (MD 18.4, 95% CI 7.6-29.3, P = .001), mental health (MD 11.7, 95% CI 3.06-20.4, P = .009), and social functioning (MD 14.2, 95% CI 1.13-27.2, P = .03) were considerably lower in patients with the highest versus the lowest DII. QoL did not differ between normal-weight and obese patients with low DII (P = .26), and between normal-weight and obese patients with high DII (P = .13). Obese patients with low DII also had better QoL than normal-weight subjects with high DII scores.

CONCLUSIONS

A diet with higher proinflammatory potential was associated with decreased QoL, irrespective of obesity status. Adherence to a low-DII diet might protect against some obesity-associated complications, a finding that needs further investigations.

Modified Creatinine Index and Clinical Outcomes of Hemodialysis Patients: An Indicator of Sarcopenia?

OBJECTIVE

Sarcopenia (especially muscle mass assessed using gold standard techniques) has been suggested as a poorer predictor of mortality than muscle function in patients undergoing hemodialysis. Appropriate methods to estimate muscle mass for use as a good predictor of clinical outcomes remain to be established. We investigated whether the modified creatinine index (mCI), which is a surrogate marker of muscle mass, could predict mortality and cardiovascular (CV) hospitalizations independent of muscle function and other confounders in patients on hemodialysis.

DESIGN AND METHODS

In this retrospective study, outpatients (n = 542; mean age, 65.3 years; 60% men; median dialysis vintage, 29 months; mean BMI, 22.0 kg/m²) undergoing hemodialysis were investigated. The mCI, handgrip strength, and gait speed were assessed and related to all-cause mortality and a composite of CV hospitalizations and all-cause mortality. Cox proportional and mixed-effects negative binomial models were fit for mortality and the composite outcomes.

RESULTS

Patients were followed up for a median 3 years (interquartile range: 1.5-5.7). Each per SD increase of mCI (HR:0.63, 95% CI:0.62-0.65), handgrip strength (HR:0.51, 95% CI:0.48-0.54), and gait speed (HR:0.60, 95% CI:0.56-0.64) were significantly associated with lower all-cause mortality rates after adjusting for covariates. The mCI was consistently found to be an independent predictor of mortality after additional adjustment for handgrip strength or gait speed. Furthermore, sarcopenic conditions [i.e., lower mCI, and lower handgrip strength (HR:3.79, 95% CI:2.09-6.87) or slower gait speed (HR:4.20, 95% CI:2.38-7.41)] were significantly associated with a higher risk of mortality after adjusting for covariates. Associations of mCI with multiple CV hospitalizations and mortality were similar to those between mCI and mortality.

CONCLUSION

The mCI was a good predictor of clinical outcomes and was comparable to muscle function, including handgrip strength and gait speed. The mCI is likely to provide additional diagnostic and prognostic values for sarcopenia in patients on hemodialysis.

Calycosin inhibited autophagy and oxidative stress in chronic kidney disease skeletal muscle atrophy by regulating AMPK/SKP2/CARM1 signalling pathway

Skeletal muscle atrophy is a common and serious complication of chronic kidney disease (CKD). Oxidative stress and autophagy are the primary molecular mechanisms involved in muscle atrophy. Calycosin, a major component of Radix astragali, exerts anti‐inflammatory, anti‐oxidative stress and anti‐autophagy effects. We investigated the effects and mechanisms of calycosin on skeletal muscle atrophy in vivo and in vitro. 5/6 nephrectomy (5/6 Nx) rats were used as a model of CKD. We evaluated bodyweight and levels of serum creatinine (SCr), blood urea nitrogen (BUN) and serum albumin (Alb). H&E staining, cell apoptosis, oxidative stress biomarkers, autophagosome and LC3A/B levels were performed and evaluated in skeletal muscle of CKD rat. Calycosin treatment improved bodyweight and renal function, alleviated muscle atrophy (decreased the levels of MuRF1 and MAFbx), increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH‐Px) activity and reduced malondialdehyde (MDA) levels in skeletal muscle of CKD rats. Importantly, calycosin reduced autophagosome formation, down‐regulated the expression of LC3A/B and ATG7 through inhibition of AMPK and FOXO3a, and increased SKP2, which resulted in decreased expression of CARM1, H3R17me2a. Similar results were observed in C2C12 cells treated with TNF‐α and calycosin. Our findings showed that calycosin inhibited oxidative stress and autophagy in CKD induced skeletal muscle atrophy and in TNF‐α‐induced C2C12 myotube atrophy, partially by regulating the AMPK/SKP2/CARM1 signalling pathway.

The effects of amino acid/protein supplementation in hemodialysis patients: study protocol for a systematic review and meta-analysis

Background

Multiple factors including older age, comorbidities, inflammation, metabolic acidosis, dialysis-related hypercatabolism and anabolic resistance of skeletal muscle, extraction of circulating amino acids through hemodialysis and inadequate dietary protein intake due to anorexia, and strictly limited dietary phosphorus intake are likely to contribute to the high prevalence of malnutrition and metabolic abnormalities, more aptly called protein-energy wasting, in patients on hemodialysis. The consensus from the International Society of Renal Nutritional and Metabolism states that nutritional supplementation is effective for replenishing protein and energy stores. Although we hypothesize that amino acid/protein supplementation can overcome the anabolic resistance of skeletal muscle tissue and attenuate or even prevent the accelerated loss of skeletal muscle mass and strength through nutritional status improvement in patients on hemodialysis, whether amino acid and/or protein administration is associated with improvements in these outcomes is unknown. The main objective of this study is to systematically review the impact of amino acid/protein supplementation on skeletal muscle mass, muscle strength, physical function, and quality of life in end-stage renal disease patients requiring hemodialysis.

Methods

Published randomized controlled trials (RCTs) assessing the effectiveness of amino acid/protein supplementation in hemodialysis patients with respect to body composition, muscle mass, muscle strength, physical function, and quality of life will be included. The bibliographic databases include MEDLINE, the Web of Science, the Cochrane Central Register of Controlled Trials, and Embase. The risk of bias of the included RCTs will be assessed using the Cochrane Collaboration’s tool by two independent reviewers. The primary outcome will be skeletal muscle mass, muscle strength, and physical function, and the secondary outcome will be quality of life. This review protocol is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) 2015 checklist.

Ethics and dissemination

Ethical approval is not required because this study does not include confidential personal data or involve patient interventions. This review is expected to inform readers on the effect of amino acid/protein supplementation in patients undergoing hemodialysis. The findings will be presented at conferences and submitted to a peer-reviewed journal for publication.

Trial registration

The trial registration number is (CRD42020181087), and the trial was registered on 5 July 2020.

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.

Association between Serum Uric Acid Levels, Nutritional and Antioxidant Status in Patients on Hemodialysis

Purpose: To determine the relationship between uric acid (UA) and nutritional and antioxidant status in hemodialysis (HD) patients, given that hyperuricemia could be an indicator of good nutritional status possibly because of the antioxidant properties of UA. Methods: Cross-sectional study with 93 patients on HD. Hyperuricemia was considered as UA ≥6.0 mg/dL in females and ≥7.0 mg/dL in males. Nutritional variables were registered. Blood samples were taken before the dialysis session to determine oxidative damage as plasma malondialdehyde (MDA) content, and antioxidant capacity measuring 2,2-diphenyl-piclrylhidrazil radical (DPPH^●) scavenging activity and oxygen radical absorbance capacity (ORAC) value. Results: Patients with hyperuricemia had higher creatinine (11.9 vs. 10.5 mg/dL; p = 0.004), potassium (5.5 vs. 5.0 mg/dL; p = 0.014) levels; phase angle (5.8 vs. 4.9; p = 0.005), protein consumption (normalized protein nitrogen appearance, nPNA, 1.03 vs. 0.83; p = 0.013) than normouricemic patients. DPPH^● scavenging activity was higher in hyperuricemic subjects (1.139 vs. 1.049 mM Trolox equivalents; p = 0.007); likewise, hyperuricemic subjects had less oxidant damage measured by MDA (10.6 vs. 12.7 nmol/mL; p = 0.020). Subjects with normouricemia were at higher risk of having a reactance to height (Xc/H) ratio less than 35 (OR 2.79; 95% CI, 1.1–7.017, p = 0.028); nPNA < 1.0 (OR 3.78; 95% CI, 1.4–10.2, p = 0.007), diagnosis of cachexia (OR 2.95; 95% CI, 1156–7.518, p = 0.021), potassium levels <5 (OR 2.97; 95% CI, 1.136–7.772, p = 0.023) and PA < 5.5° (OR 3.38; 95% CI, 1.309–8.749, p = 0.012.) Conclusions: Patients with hyperuricemia had higher antioxidant capacity and better nutritional status. Purines and protein restrictions in HD patients with hyperuricemia need to be reviewed individually for each patient. More studies are needed to stablish a cut point of UA levels in renal population.

The Prevalence of Frailty and its Association with Cognitive Dysfunction among Elderly Patients on Maintenance Hemodialysis: A Cross-Sectional Study from South India

Data are scarce regarding the prevalence of frailty in elderly patients undergoing maintenance hemodialysis (HD) in India. We conducted a cross-sectional observational study aimed to study the prevalence of frailty and cognitive dysfunction in patients aged 75 years or more undergoing maintenance HD in three tertiary care hospitals and associated stand-alone dialysis centers in North Kerala. Frailty was ascertained by two methods. In method 1 (physical performance measurement based), dichotomous scoring (0 or 1) of five domains, namely weight loss, exhaustion, low physical activity, weak grip, and slow walking, was done, and a score of 3/5 was used to define frailty. In method 2 (self-report measure based), scores on the Medical Outcomes Study Short-Form 36-item Questionnaire (SF-36) physical function domain were used instead of hand grip strength and walking speed, and a score of <75 was defined as meeting the criteria for weakness and slow walking. Cognitive function was documented using the Montreal Cognitive Assessment Instrument. A total of 899 patients were screened, of whom 44 were aged 75 years or more and 39 met the criteria for inclusion. The majority (n = 31, 79.5%) had ages between 75 and 80 years and were male. Dialysis vintage was <1 year in 15.4%, 1-3 years in 51.3%, and >3 years in 33.3% of patients. Frailty was documented in 22 (56.4%) patients by method 1 and in 25 (64.1%) by method 2. There was a statistically significant difference between the two methods in documenting frailty (P < 0.001, Chi-square test). Cognitive impairment was present in 89.7% of patients and significantly associated with frailty (P < 0.001, Fisher's exact test). Frailty and cognitive dysfunction are highly prevalent in elderly people undergoing maintenance HD in North Kerala. Physical performance and self-report measure-based methods correlate well in frailty documentation.

Phosphatemic Index Is a Novel Evaluation Tool for Dietary Phosphorus Load: A Whole-Foods Approach

OBJECTIVE

Dietary phosphorus (P) restriction is crucial to treat hyperphosphatemia and reduce cardiovascular disease risk and mortality in patients with chronic kidney disease (CKD) and the wider population. Various methods for dietary P restriction exist, but the bioavailability of P in food should also be considered when making appropriate food choices to maintain patients' quality of life. Here, we propose the "Phosphatemic Index" (PI) as a novel tool for evaluating dietary P load based on P bioavailability; we also evaluated the effect of continuous intake of different PI foods in mixed meals on serum intact fibroblast growth factor 23 concentration.

DESIGN AND METHODS

A 2-stage crossover study was conducted: Study 1: 20 healthy participants consumed 10 different foods containing 200 mg of P, and the PI was calculated from the area under the curve of a time versus serum P concentration curve; Study 2: 10 healthy participants consumed 4 different test meals (low, medium, or high PI meals or a control) over a 5-day period.

RESULTS

Study 1 showed milk and dairy products had high PI values, pork and ham had medium PI values, and soy and tofu had low PI values. In Study 2, ingestion of high PI test meals showed higher fasting serum intact fibroblast growth factor 23 levels and lower serum 1,25-dihydroxyvitamin D levels compared with ingestion of low PI test meals.

CONCLUSION

These findings suggest that the PI can usefully evaluate the dietary P load of various foods and may help to make appropriate food choices for dietary P restriction in CKD patients.

Effects of fish oil during hemodialysis on nutritional status and quality of life: a randomized double-blinded trial

Background

Supplementation of fish oil has been shown to exert beneficial effects in patients undergoing hemodialysis. The aim of this study was to investigate the efficacy of fish oil in improving the quality of life of these patients through a randomized, double-blinded clinical trial.

Methods

Among the 103 patients enrolled in the study, a total of 74 patients were randomized to receive fish oil (intervention group) or placebo (n=37 per group). Patients received identical soft-gel capsules, with each capsule containing either 1000 mg fish oil or placebo for 4 months. Personnel responsible for data collection and analyses were blinded to the grouping.

Results

The reduction of protein-energy wasting (PEW) in the intervention group was significantly more prominent compared to the placebo group (P=0.023). The intervention group demonstrated significant increase in midarm circumference, arm muscle circumference, and triceps skinfold thickness after fish oil intake. The intervention group also exhibited significant differences from the placebo group in creatinine, uric acid, and serum calcium levels. Significant improvement was seen regarding the physical role and energy/figure in the intervention group.

Conclusions

Our study demonstrated that fish oil intake in patient undergoing hemodialysis can significantly reduce PEW, and improve physical and biochemical parameters and quality of life, which could provide guidance to clinical management of these patients.

Hemodialysis Affects Wanting and Spontaneous Intake of Protein-Rich Foods in Chronic Kidney Disease Patients

OBJECTIVES

Protein-energy wasting is a risk factor for mortality and morbidity in hemodialysis patients (HD patients). Food intake could be modified by HD-related changes in the food reward system (i.e., liking and wanting of specific macronutrients). In HD patients on days with and without dialysis, we evaluated (1) the reward system for protein-, fat-, and carbohydrate-rich foods, plasma hormones, and metabolite changes; and (2) the spontaneous ad libitum intake of macronutrients.

(DESIGN AND) METHODS

Twenty-four HD patients evaluated their liking and wanting of macronutrients at 7:30 AM and 11:30 AM on a day with and a day without dialysis. Concentrations of hormones and plasma amino acids were determined. An additional 18 HD patients ate what they wanted from a buffet lunch comprising 8 dishes on a day with and a day without dialysis. Healthy subjects, age-, sex-, and body mass index-matched, served as controls.

RESULTS

At 11:30 AM, wanting for protein-rich foods was higher on the day with than on the day without dialysis (P < .01), bringing wanting levels close to those of healthy subjects. This increase correlated with changes in the concentrations of plasma amino acids (P < .01). HD patients ate more protein from the buffet on the day with than on the day without dialysis (P < .01) and more than healthy subjects (P < .01).

CONCLUSIONS

In HD patients, wanting and spontaneous intake of protein-rich foods increase immediately after dialysis. This increase correlated with decreased concentrations of plasma amino acids. Thus, in clinical practice, protein-rich foods should be recommended during and after dialysis in patients with protein-energy wasting.

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.

The Effects of Synbiotic Supplementation on Metabolic Status in Diabetic Patients Undergoing Hemodialysis: a Randomized, Double-Blinded, Placebo-Controlled Trial

This study was conducted to evaluate the effects of synbiotic supplementation on metabolic profiles in diabetic patients undergoing hemodialysis (HD). This randomized, double-blinded, placebo-controlled clinical trial was performed in 60 diabetic HD patients. Participants were randomly assigned into two groups to receive either synbiotic capsule, containing Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidum (2 × 10⁹ CFU/g each), plus 0.8 g/day of inulin (n = 30) or placebo (n = 30) for 12 weeks. Synbiotic supplementation significantly decreased fasting plasma glucose (β - 13.56 mg/dL; 95% CI, - 23.82, - 3.30; P = 0.01), insulin levels (β - 5.49 μIU/mL; 95% CI, - 6.92, - 4.05; P < 0.001), and insulin resistance (β - 2.25; 95% CI, - 3.02, - 1.48; P < 0.001), while increased the quantitative insulin sensitivity check index (β 0.02; 95% CI, 0.01, 0.02; P < 0.001) compared with the placebo. Additionally, synbiotic intake resulted in a significant reduction in high-sensitivity C-reactive protein (β - 2930.48 ng/mL; 95% CI, - 3741.15, - 2119.80; P < 0.001) and malondialdehyde levels (β - 0.60 μmol/L; 95% CI, - 0.99, - 0.20; P = 0.003). Moreover, we found a significant increase in total antioxidant capacity (β 142.99 mmol/L; 95% CI, 61.72, 224.25; P = 0.001) and total glutathione levels (β 131.11 μmol/L; 95% CI, 89.35, 172.87; P < 0.001) in the synbiotic group compared with the placebo group. Overall, synbiotic supplementation for 12 weeks had beneficial effects on glycemic control, biomarkers of inflammation, and oxidative stress in diabetic patients under HD. This study was registered in the Iranian website (www.irct.ir) for registration of clinical trials (http://www.irct.ir: IRCT2017090133941N17). http://www.irct.ir: IRCT2017090133941N17.

Evaluation of a novel non-surgical post-pyloric feeding technique in dogs with severe acute kidney injury

OBJECTIVES

To evaluate the placement and the performance of a new post-pyloric feeding (PPF) system, and compare it to esophageal (E) feeding in dogs with severe acute kidney injury (AKI).

DESIGN

Prospective study.

SETTING

University teaching hospital.

ANIMALS

Twenty client-owned dogs with severe AKI treated with hemodialysis.

INTERVENTIONS

Dogs were randomly assigned to 2 feeding techniques, PPF or E feeding; for PPF, an 8-Fr jejunal (J) tube was introduced through a standard 18-Fr E-tube and advanced endoscopically through the pylorus. A commercial liquid diet was administered at a continuous rate for at least 5 days. After the removal of the internal J-tube, feeding was continued through the E-tube. Control dogs were fed blended food 5 times daily through an E-tube. Placement technique, nutritional efficiency, and metabolic response to nutritional support were compared between the groups.

MEASUREMENTS AND MAIN RESULTS

Feeding tubes were placed a medium of 1 day (interquartile range, 0.8 d) after presentation. Median procedure-time in the group PPF was 26.5 min (11.5 min), including 8.5 min (2.7 min) for the E-tube and 17.5 min (5.0 min) for the J-tube. J-tubes were used for 5 days (1.5 d) with oral displacement observed in 3/10 dogs. The goal to administer 130% resting energy requirement within 3 days was reached in 13/20 dogs (8/10 PPF, 5/10 E). Despite nutritional support, dogs lost 1.2% body weight per day (1.1%), with no difference between the groups. The metabolic improvement was comparable between the groups, despite marked differences in the diet composition.

CONCLUSIONS

This new feeding technique can be recommended as an efficient method for early nutritional support in dogs with severe AKI. The protein-energy wasting observed despite active nutritional support suggests, however, the necessity for increased feeding targets or qualitative changes in diet composition for dogs with AKI.