Intradialytic parenteral nutrition does not improve survival in malnourished hemodialysis patients: a 2-year multicenter, prospective, randomized study

Clinical Practice Guideline on management of older patients with chronic kidney disease stage 3b or higher (eGFR<45 mL/min/1.73 m2): a summary document from the European Renal Best Practice Group

The population of patients with moderate and severe CKD is growing. Frail and older patients comprise an increasing proportion. Many studies still exclude this group, so the evidence base is limited. In 2013 the advisory board of ERBP initiated, in collaboration with European Union of Geriatric Medicine Societies (EUGMS), the development of a guideline on the management of older patients with CKD stage 3b or higher (eGFR >45 mL/min/1.73 m2). The full guideline has recently been published and is freely available online and on the website of ERBP (www.european-renal-best-practice.org). This paper summarises main recommendations of the guideline and their underlying rationales.

Sex and gender differences in chronic kidney disease: progression to end-stage renal disease and haemodialysis

Sex and gender differences are of fundamental importance in most diseases, including chronic kidney disease (CKD). Men and women with CKD differ with regard to the underlying pathophysiology of the disease and its complications, present different symptoms and signs, respond differently to therapy and tolerate/cope with the disease differently. Yet an approach using gender in the prevention and treatment of CKD, implementation of clinical practice guidelines and in research has been largely neglected. The present review highlights some sex- and gender-specific evidence in the field of CKD, starting with a critical appraisal of the lack of inclusion of women in randomized clinical trials in nephrology, and thereafter revisits sex/gender differences in kidney pathophysiology, kidney disease progression, outcomes and management of haemodialysis care. In each case we critically consider whether apparent discrepancies are likely to be explained by biological or psycho-socioeconomic factors. In some cases (a few), these findings have resulted in the discovery of disease pathways and/or therapeutic opportunities for improvement. In most cases, they have been reported as merely anecdotal findings. The aim of the present review is to expose some of the stimulating hypotheses arising from these observations as a preamble for stricter approaches using gender for the prevention and treatment of CKD and its complications.

Could intradialytic nutrition improve refractory anaemia in patients undergoing haemodialysis?

BACKGROUND

This prospective randomised study was designed to evaluate the efficacy of intradialytic parenteral nutrition (IDPN) therapy in malnourished patients with refractory anaemia.

METHODS

Forty patients who were malnourished with a BMI not greater than 23 (17-23) kg/m² , undergoing regular HD were included. Of those, 20 patients received 500-1000 ml of IDPN at a rate of 250-300 ml/h at each HD session three days per week for six consecutive months. The other 20 patients did not receive IDPN infusion. The malnutrition inflammation score (MIS) and haematological parameters were recorded at baseline and after three and six months.

RESULTS

Mean haemoglobin levels, BMI and serum albumin were significantly increased while MIS was significantly decreased after the 3rd and 6th months of IDPN.

CONCLUSION

IDPN has a good role in improving refractory anaemia by significantly increasing haemoglobin levels, body weight, and serum albumin levels. The intervention also significantly decreases the MIS of patients.

[Common therapeutic approaches of sarcopenia in the elderly and uremic myopathy]

The gradual loss of weight and function of muscle in patients with chronic kidney disease as in the elderly impacts the quality of life. Early management should help slow the functional limitation. Physical activity is the first therapy to propose that ensures stability of muscle mass and improved function. Resistance training programs have proven effective but are not yet widely available in nephrology units. The nutritional management should not be forgotten because there is a resistance to anabolism and protein intake should be involved in physical activity program. Associated treatments should not be neglected: vitamin D, anti-inflammatory, androgens. Some are still under evaluation. Therapeutic option, tomorrow, could be anti-myostatin antibodies and glitazones.

Dialysis Procedures Alter Metabolic Conditions

A progressive chronic kidney disease results in retention of various substances that more or less contribute to dysfunction of various metabolic systems. The accumulated substances are denominated uremic toxins. Although many toxins remain undetected, numerous newly defined toxins participate in the disturbance of food breakdown. In addition, toxic effects may downregulate other pathways, resulting in a reduced ability of free fatty acid breakdown by lipoprotein lipase (LPL) and hepatic lipase (HL). Dialysis may even worsen metabolic functions. For LPL and HL, the use of heparin and low molecular weight heparin as anticoagulation during hemodialysis (HD) initiate a loss of these enzymes from their binding sites and degradation, causing a temporary dysregulation in triglyceride breakdown. This lack of function will cause retention of the triglyceride containing lipids for at least 8 h. In parallel, the breakdown into free fatty acids is limited, as is the energy supply by them. This is repeated thrice a week for a normal HD patient. In addition, dialysis will cause a loss of amino acids and disturb glucose metabolism depending on the dialysates used. The addition of glucose in the dialysate may support oxidation of carbohydrate and the retention of Amadori products and subsequent tissue alterations. To avoid these effects, it seems necessary to further study the effects of anticoagulation in HD, the extent of use of glucose in the dialysate, and the supplementation of amino acids.

State of Harmonization of 24 Serum Albumin Measurement Procedures and Implications for Medical Decisions

BACKGROUND

Measurements of serum and plasma albumin are widely used in medicine, including as indicators of quality of patient care in renal dialysis centers.

METHODS

Pools were prepared from residual patient serum (n = 50) and heparin plasma (n = 48) from patients without renal disease, and serum from patients with kidney failure before hemodialysis (n = 53). Albumin was measured in all samples and in ERM-DA470k/IFCC reference material (RM) by 3 immunochemical, 9 bromcresol green (BCG), and 12 bromcresol purple (BCP) methods.

RESULTS

Two of 3 immunochemical procedures, 5 of 9 BCG, and 10 of 12 BCP methods recovered the RM value within its uncertainty. One immunochemical and 3 BCG methods were biased vs the RM value. Random error components were small for all measurement procedures. The Tina-quant immunochemical method was chosen as the reference measurement procedure based on recovery and results of error analyses. Mean biases for BCG vs Tina-quant were 1.5% to 13.9% and were larger at lower albumin concentrations. BCP methods' mean biases were −5.4% to 1.2% irrespective of albumin concentration. Biases for plasma samples were generally higher than for serum samples for all method types. For most measurement procedures, biases were lower for serum from patients on hemodialysis vs patients without kidney disease.

CONCLUSIONS

Significant differences among immunochemical, BCG, and BCP methods compromise interpretation of serum albumin results. Guidelines and calculations for clinical management of kidney and other diseases must consider the method used for albumin measurement until harmonization can be achieved.

Serum prealbumin and its changes over time are associated with mortality in acute kidney injury

Serum prealbumin is a clinically relevant indicator of nutritional status and inflammation in patients with acute kidney injury (AKI). This study aimed to determine whether serum prealbumin and its longitudinal changes over a week could improve the prediction of 90-day mortality in AKI patients. This prospective cohort study included 340 adults with AKI between 2014 and 2015. There were 94 (27.6%) patient deaths within 90 days. Serum prealbumin level <10 mg/dL at the time of AKI diagnosis was associated with a 155% increased death risk ratio (adjusted hazard ratio [HR], 2.55; 95% confidence interval [CI], 1.18 to 5.49; P = 0.02). Serum prealbumin fall >4 mg/dL was also associated with 90-day mortality in adjusted Cox regression models (HR, 1.79; 95% CI, 1.06 to 3.03; P = 0.03). Compared to serum albumin, mortality-predictability of serum prealbumin (P = 0.01) and its changes (P = 0.01) were both increased. Adding prealbumin and its changes on the conventional covariates improved the prediction of progression to 90-day mortality (NRI 0.29, P = 0.04; aIDI 0.08; P = 0.03). In conclusion, serum prealbumin, and its changes were independent predictors of worse prognosis in AKI, and could be potential surrogates to better predict 90-day mortality.

When Is Parenteral Nutrition Appropriate?

Parenteral nutrition (PN) represents one of the most notable achievements of modern medicine, serving as a therapeutic modality for all age groups across the healthcare continuum. PN offers a life-sustaining option when intestinal failure prevents adequate oral or enteral nutrition. However, providing nutrients by vein is an expensive form of nutrition support, and serious adverse events can occur. In an effort to provide clinical guidance regarding PN therapy, the Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) convened a task force to develop consensus recommendations regarding appropriate PN use. The recommendations contained in this document aim to delineate appropriate PN use and promote clinical benefits while minimizing the risks associated with the therapy. These consensus recommendations build on previous ASPEN clinical guidelines and consensus recommendations for PN safety. They are intended to guide evidence-based decisions regarding appropriate PN use for organizations and individual professionals, including physicians, nurses, dietitians, pharmacists, and other clinicians involved in providing PN. They not only support decisions related to initiating and managing PN but also serve as a guide for developing quality monitoring tools for PN and for identifying areas for further research. Finally, the recommendations contained within the document are also designed to inform decisions made by additional stakeholders, such as policy makers and third-party payers, by providing current perspectives regarding the use of PN in a variety of healthcare settings.

[Wasting in chronic kidney disease: Refeeding techniques and artificial nutrition practices]

Protein energy wasting (PEW) is an independent factor associated with morbi-mortality in chronic kidney disease. Wasting is particularly common in chronic diseases of organs such as kidney disease with a major impact at the stage of dialysis. It covers 20 to 70% of patients diagnosed with chronic kidney disease according to the degree of evolution of the disease and the diagnostic method used patients. Mechanisms of PEW are based mainly on anorexia and metabolic abnormalities caused by kidney disease. Nutritional treatment differs depending on the stage of the kidney disease acute or chronic treated whether or not by dialysis. Nutritional monitoring should be regular, individualized and collaborative to detect a risk of PEW or treat installed PEW. Refeeding techniques should allow all the nutritional needs. Their indications depend on the clinic, biochemical assessment and nutrient intake.

A combination of corticosteroid, sirolimus, and intradialytic parenteral nutrition in encapsulating peritoneal sclerosis: Case report and literature review

Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis that carries a high morbidity and mortality. Although its pathogenesis is still not clear, the "two hit theory" suggests that long term deterioration of the peritoneum combined with intraperitoneal inflammation is needed in the pathogenesis of EPS. To date, there is no proven effective therapy with an absence of randomized controlled trials. Individual case reports and small case series have reported on the use of tamoxifen and corticosteroids for medical management of EPS. Here, we present the first case of EPS treated successfully with a combination of sirolimus, low dose corticosteroid and intradialytic parenteral nutrition. A critical review of the relevant literature on this subject is also presented to determine the best approach.

Adherence to ketoacids/essential amino acids-supplemented low protein diets and new indications for patients with chronic kidney disease

BACKGROUND

Low protein diets (LPD) have long been prescribed to chronic kidney disease patients with the goals of improving metabolic abnormalities and postpone the start of maintenance dialysis.

METHODS

We reviewed the recent literature addressing low protein diets supplemented with ketoacids/essential aminoacids prescribed during chronic kidney disease and their effects on metabolic, nutritional and renal parameters since 2013.

RESULTS

We show new information on how to improve adherence to these diets, on metabolic improvement and delay of the dialysis needs, and preliminary data in chronic kidney disease associated pregnancy. In addition, data on incremental dialysis have been reviewed, as well as potential strategies to reverse protein energy wasting in patients undergoing maintenance dialysis.

CONCLUSION

These recent data help to better identify the use of low protein diets supplemented with ketoacids/essential aminoacids during chronic kidney disease.

Protein-energy wasting and nutritional supplementation in patients with end-stage renal disease on hemodialysis

BACKGROUND & AIMS

Protein-Energy Wasting (PEW) is the depletion of protein/energy stores observed in the most advanced stages of Chronic Kidney Disease (CKD). PEW is highly prevalent among patients on chronic dialysis, and is associated with adverse clinical outcomes, high morbidity/mortality rates and increased healthcare costs. This narrative review was aimed at exploring the pathophysiology of PEW in end-stage renal disease (ESRD) on hemodialysis. The main aspects of nutritional status evaluation, intervention and monitoring in this clinical setting were described, as well as the current approaches for the prevention and treatment of ESRD-related PEW.

METHODS

An exhaustive literature search was performed, in order to identify the relevant studies describing the epidemiology, pathogenesis, nutritional intervention and outcome of PEW in ESRD on hemodialysis.

RESULTS AND CONCLUSION

The pathogenesis of PEW is multifactorial. Loss of appetite, reduced intake of nutrients and altered lean body mass anabolism/catabolism play a key role. Nutritional approach to PEW should be based on a careful and periodic assessment of nutritional status and on timely dietary counseling. When protein and energy intakes are reduced, nutritional supplementation by means of specific oral formulations administered during the hemodialysis session may be the first-step intervention, and represents a valid nutritional approach to PEW prevention and treatment since it is easy, effective and safe. Omega-3 fatty acids and fibers, now included in commercially available preparations for renal patients, could lend relevant added value to macronutrient supplementation. When oral supplementation fails, intradialytic parenteral nutrition can be implemented in selected patients.

Comparison of Intradialytic Parenteral Nutrition with Glucose or Amino Acid Mixtures in Maintenance Hemodialysis Patients

Many long-term maintenance hemodialysis patients have symptoms of protein-energy wasting caused by malnutrition. Each session of hemodialysis removes about 10 to 12 g of amino acids and 200 to 480 kcal of energy. Patients receiving hemodialysis for chronic kidney disease may be undernourished for energy, protein consumption, or both. Non-diabetic hemodialysis patients were randomized to three treatment groups: oral supplementation, oral supplementation plus high-concentration glucose solution (250 mL containing 50% glucose) and these two interventions plus 8.5% amino acids solution. The post-treatment energy status of the glucose group was significantly higher than its baseline level, whereas the control group’s status was significantly lower. The glucose group had significantly higher concentrations of asparagine, glutamine, glycine, alanine, and lysine after treatment. All treatment groups had significantly increased hemoglobin levels but significantly decreased transferrin levels after treatment compared to baseline. After treatment, the amino acid group had significantly higher albumin level compared to the glucose group (p = 0.001) and significantly higher prealbumin level compared to the control group (p = 0.017). In conclusion, long-term intervention with high-concentration glucose solution at each hemodialysis session is a simple and cheap method that replenished energy stores lost during hemodialysis of non-diabetic patients.

Back to the future: restricted protein intake for conservative management of CKD, triple goals of renoprotection, uremia mitigation, and nutritional health

Lowering dietary protein intake (DPI) to approximately 0.6-0.8 g/kgBW/day may be renoprotective through various mechanisms, and it has been recommended in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) as a means to also control various metabolic consequences of advanced CKD, such as uremic symptoms, hyperparathyroidism, hypertension, hyperkalemia, and hyperphosphatemia. A meta-analysis in this issue of the Journal suggests that low-protein diet is effective and safe when used to retard progression of CKD and alleviate uremic complications. A potential deleterious consequence of lowering DPI in this population is the development or worsening of protein-energy wasting (PEW), which can contribute to poor clinical outcomes such as higher mortality and morbidity. There is currently insufficient high-level evidence to determine the ideal level of DPI in patients with NDD-CKD with high risk of PEW. For the time being we recommend a DPI of 0.6-0.8 g/kgBW/day, and increasing this as needed on an individual basis in patients with PEW. Further examination of this dilemma in randomized controlled clinical trials will be necessary.

Clinical management of the uraemic syndrome in chronic kidney disease

The clinical picture of the uraemic syndrome is a complex amalgam of accelerated ageing and organ dysfunction, which progress in parallel to chronic kidney disease. The uraemic syndrome is associated with cardiovascular disease, metabolic bone disease, inflammation, protein energy wasting, intestinal dysbiosis, anaemia, and neurological and endocrine dysfunction. In this Review, we summarise specific, modern management options for the uraemic syndrome in chronic kidney disease. Although large randomised controlled trials are scarce, based on data from randomised controlled trials and observational studies, as well as pathophysiological reasoning, a therapeutic algorithm can be developed for this complex and multifactorial condition, with interventions targeting several modifiable factors simultaneously.

Assessment of some cardiovascular risk factors in predialysis chronic kidney disease patients in Southern Nigeria

BACKGROUND

Cardiovascular risk factors are responsible for cardiovascular disease and rapid progression of chronic kidney disease (CKD) to end-stage renal disease. Prompt evaluation, modification, and treatment of these factors in predialysis patients will reduce morbidity and mortality. This study assessed some cardiovascular risk factors in predialysis CKD patients in a tertiary hospital in Southern Nigeria.

PATIENTS AND METHODS

This was a case-control study that involved 76 consecutive predialysis CKD patients and 38 age-and sex-matched controls without CKD over 1 year period. Both groups were assessed for cardiovascular risk factors, and comparisons were made. A P value of <0.05 was taken as significant.

RESULTS

The mean ages of the CKD versus control group were 48.00 ± 15.28 versus 45.34 ± 15.35 years. The male:female ratio was 1.7:1 for both groups. The common etiologies of CKD in this study were hypertension 30 (39.5%), diabetes mellitus 23 (30.3%), and chronic glomerulonephritis 19 (25%). There were 38 (50%) in CKD stage 3, 31 (40.8%) in CKD stage 4, and 7 (9.2%) in CKD stage 5. The common cardiovascular risk factors found in the CKD versus control were hypertension (96.1% vs. 42.1%), anemia (96.1% vs. 23.7%), left ventricular hypertrophy (77.6% vs. 23.7%), dyslipidemia (67.1% vs. 39.5%), hypocalcemia (60.1% vs. 18.5%), hyperphosphatemia (63.2% vs. 0%), and hyperuricemia (57.9% vs. 15.8%). These risk factors were significantly higher in CKD group. Hyperphosphatemia and hypoalbuminemia significantly increased across CKD stages 3-5. Anemia was significantly more common in males whereas dyslipidemia was more common in female CKD patients.

CONCLUSION

Cardiovascular risk factors were highly prevalent in predialysis CKD subjects even in early stages. Hypoalbuminemia and hyperphosphatemia significantly increased across the CKD stages 3-5 whereas anemia and dyslipidemia showed significant gender differences. Cardiovascular risk factors should be treated early in predialysis CKD patients.

Malnutrition in Dialysis Patients--The Need for Intervention Despite Uncertain Benefits

We are in the midst of an epidemic of overnutrition which has resulted in a widespread increase in obesity rates in modern societies. Yet for patients suffering from serious chronic illnesses such as end stage renal disease (ESRD), malnutrition (encompassing both inadequate quantity and quality of nutrient intake) represents a far more significant danger. Protein-energy wasting has been identified as one of the strongest risk factor for adverse outcomes in ESRD patients, and modeling studies have suggested that improving nutrition could result in substantial lowering of mortality rates and other benefits. To date there is ample evidence that various interventions can have a positive impact on the nutritional status of ESRD patients, yet we still lack randomized controlled clinical trials showing that the same interventions could indeed lead to better survival or other clinical benefits. This knowledge gap, which is all too common for clinical problems encountered in nephrology, should not act as a deterrent, but it should rather incentivize us to continue exploring novel interventions aimed at improving malnutrition in ESRD.

Cross-sectional examination of metabolites and metabolic phenotypes in uremia

BACKGROUND

Although metabolomic approaches have begun to document numerous changes that arise in end stage renal disease (ESRD), how these alterations relate to established metabolic phenotypes in uremia is unknown.

METHODS

In 200 incident hemodialysis patients we used partial least squares discriminant analysis to identify which among 166 metabolites could best discriminate individuals with or without diabetes, and across tertiles of body mass index, serum albumin, total cholesterol, and systolic blood pressure.

RESULTS

Our data do not recapitulate metabolomic signatures of diabetes and obesity identified among individuals with normal renal function (e.g. elevations in branched chain and aromatic amino acids) and highlight several potential markers of diabetes status specific to ESRD, including xanthosine-5-phosphate and vanillylmandelic acid. Further, our data identify significant associations between elevated tryptophan and long-chain acylcarnitine levels and both decreased total cholesterol and systolic blood pressure in ESRD. Higher tryptophan levels were also associated with higher serum albumin levels, but this may reflect tryptophan's significant albumin binding. Finally, an examination of the uremic retention solutes captured by our platform in relation to 24 clinical phenotypes provides a framework for investigating mechanisms of uremic toxicity.

CONCLUSIONS

In sum, these studies leveraging metabolomic and metabolic phenotype data acquired in a well-characterized ESRD cohort demonstrate striking differences from metabolomics studies in the general population, and may provide clues to novel functional pathways in the ESRD population.

Supervised oral protein supplementation during dialysis in patients with elevated C-reactive protein levels: a two phase, longitudinal, single center, open labeled study

BACKGROUND

Inflammation is considered one of the major causes of protein-energy wasting in maintenance hemodialysis (MHD) patients. It is unclear whether dietary interventions can impact nutritional status and quality of life in MHD patients with elevated C-reactive protein (CRP) levels. Therefore, we examined the hypothesis that supervised intra-dialysis protein supplementation in MHD patients with elevated plasma CRP will improve protein stores and quality of life.

METHODS

A 24 week, two phase, longitudinal, single center, open labeled study of 50 MHD patients with plasma CRP > 3 mg/L was conducted. During the 12-week observation phase dietary advice was provided to increase protein intake to 1.2 g/kg/day. In the 12-week treatment phase 45 g of liquid protein supplement was provided at each dialysis treatment. Protein nitrogen appearance (PNA), mid-arm muscle circumference (MAMC), serum albumin, body mass index (BMI) and quality of life (assessed by Short Form-12 questionnaire) were measured at baseline, 12 and 24 weeks.

RESULTS

Median plasma CRP at baseline was 16.0 (IQR 7.7 to 25.1) mg/L. The mean MAMC was 26.5 ± 3.9 cm, BMI 29.2 ± 6.9 kg/m(2) and plasma albumin 3.8 ± 0.3 g/dl. During the intervention period, mean PNA increased by 0.13 g/kg/d (p = 0.01) under a mixed effects model. However, there were no clinically or statistically significant effects on MAMC (p = 0.87), plasma albumin (p = 0.70), BMI (p = 0.09), physical (p = 0.32) or mental (p = 0.96) composite scores.

CONCLUSIONS

In MHD patients with elevated plasma CRP but otherwise mostly normal nutritional parameters, intra-dialytic oral protein supplement was effective in increasing protein intake but did not provide a detectable impact on nutritional status or quality of life.

The Effects of Parenteral Amino Acid Therapy on Protein Carbamylation in Maintenance Hemodialysis Patients

OBJECTIVE

Protein carbamylation is a urea-driven post-translational protein modification associated with mortality in dialysis patients. Free amino acids (AAs) are competitive inhibitors of protein carbamylation and animal studies suggest increasing AA concentrations reduces carbamylation burden. We hypothesized that AA therapy in maintenance hemodialysis patients would reduce carbamylation, carrying the potential to improve clinical outcomes.

DESIGN

Prospective pilot clinical trial (NCT1612429).

SETTING

The study was conducted from March 2013 to March 2014 in outpatient dialysis facilities in the Boston metropolitan area.

SUBJECTS AND INTERVENTION

We enrolled 23 consecutively consenting hemodialysis subjects, infusing the first 12 individuals with 250 cc of AAs 3 times per week postdialysis over 8 weeks. The remaining 11 subjects served as controls.

MAIN OUTCOME MEASURE

Change in carbamylated albumin (C-Alb), a measure of total body carbamylation burden, between baseline and 8 weeks was the primary outcome.

RESULTS

The treated and control groups had similar clinical characteristics and similar baseline C-Alb levels (mean ± SE 9.5 ± 2.4 and 9.3 ± 1.3 mmol/mol, respectively; P = .61). The treated arm showed a significant reduction in C-Alb compared with controls at 4 weeks (8.4% reduction in the treated arm vs. 4.3% increase in controls; P = .03) and the effect was greater by 8 weeks (15% reduction in the treated vs. 1% decrease in controls; P = .01).

CONCLUSION

In this pilot study, AA therapy appeared safe and effective at reducing C-Alb levels in hemodialysis patients compared with no treatment. The impact of reduced protein carbamylation on clinical outcomes should be further investigated.

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

OBJECTIVE

Protein malnutrition is both a cause and consequence of inflammation and related comorbidities for maintenance hemodialysis (MHD) patients. This study sought to determine if oral supplementation with soy or whey protein during dialysis treatment reduces inflammation and improves physical function and body composition in MHD patients.

DESIGN

The design used in the study was randomized controlled trial, and the setting used was hemodialysis clinics in Champaign and Chicago, Illinois.

SUBJECTS

Patients who received treatment ≥3 days/week, were ages ≥30 years did not have congestive heart failure or chronic obstructive pulmonary disease, and were receiving dialysis treatment for ≥3 months were eligible for inclusion.

INTERVENTION

Patients were randomized to oral supplementation with a whey protein, soy protein, or placebo beverage. Patients (WHEY, n = 11; SOY, n = 12; CON, n = 15) consumed their assigned beverage before every dialysis session for 6 months.

MAIN OUTCOME MEASURES

Body composition was measured by dual-energy x-ray absorptiometry, physical function by gait speed and shuttle walk test, and markers of inflammation (C-reactive protein and interleukin 6) using commercially available enzyme-linked immunosorbent assay kits before and after the 6-month intervention. Dietary intake was assessed by 24-hour dietary recalls.

RESULTS

Six months of whey or soy supplementation significantly reduced predialysis interleukin 6 levels (P < .05 for both), whereas there was a trend for a reduction in C-reactive protein when both protein groups were combined (P = .062). Gait speed and shuttle walk test performance also significantly improved in the protein groups (P < .05 for both). No changes in body composition were observed. However, alkaline phosphatase, a marker of bone turnover, was significantly reduced in the protein groups.

CONCLUSIONS

Intradialytic protein supplementation during a 6-month intervention reduced inflammation and improved physical function and represents an affordable intervention to improve the health of MHD patients.

Survival of patients with chronic respiratory failure on long-term oxygen therapy and or non-invasive ventilation at home

BACKGROUND & AIMS

Chronic respiratory failure (CRF) is the common fate of respiratory diseases where systemic effects contribute to outcomes. In a prospective cohort of home-treated patients with CRF, we looked for predictors of long-term survival including respiratory, nutritional and inflammatory dimensions.

METHODS

637 stable outpatients with CRF, 397 men, 68 ± 11 years, on long-term oxygen therapy and/or non-invasive ventilation from 21 chest clinics were enrolled and followed over 53 ± 31 months. CRF resulted from Chronic Obstructive Pulmonary Disease (COPD) in 48.5%, restrictive disorders 32%, mixed (obstructive and restrictive patterns) respiratory failure 13.5%, bronchiectasis 6%. Demographic characteristics, smoking habits, underlying respiratory diseases, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), arterial blood gases, 6-min walking distance (6MWD), hemoglobin, body mass index (BMI), serum albumin, transthyretin, C-reactive protein (CRP), history of respiratory assistance, antibiotic and oral corticosteroid use during the previous year were recorded.

RESULTS

322 deaths occurred during the follow-up. One-, five- and 8-year actuarial survival was 89%, 56% and 47%. By Cox univariate analysis, age, respiratory disease, PaO2, PaCO2, FEV1/FVC, BMI, 6MWD, activity score, type and length of home respiratory assistance, smoking habits, oral corticosteroid and antibiotic uses, albumin, transthyretin, hemoglobin and CRP levels were associated with survival. Multivariate analysis identified eight independent markers of survival: age, FEV1/FVC, PaO2, PaCO2, 6MWD, BMI, serum transthyretin, CRP ≥ 5 mg/l.

CONCLUSIONS

In CRF, whatever the underlying diseases, besides the levels of obstructive ventilatory defect and gas exchange failure, 6MWD, BMI, serum transthyretin and CRP ≥ 5 mg/l predicted long-term survival identifying potential targets for nutritional rehabilitation.

Mechanisms of muscle wasting in chronic kidney disease

In patients with chronic kidney disease (CKD), loss of cellular proteins increases the risks of morbidity and mortality. Persistence of muscle protein catabolism in CKD results in striking losses of muscle proteins as whole-body protein turnover is great; even small but persistent imbalances between protein synthesis and degradation cause substantial protein loss. No reliable methods to prevent CKD-induced muscle wasting currently exist, but mechanisms that control cellular protein turnover have been identified, suggesting that therapeutic strategies will be developed to suppress or block protein loss. Catabolic pathways that cause protein wasting include activation of the ubiquitin-proteasome system (UPS), caspase-3, lysosomes and myostatin (a negative regulator of skeletal muscle growth). These pathways can be initiated by complications associated with CKD, such as metabolic acidosis, defective insulin signalling, inflammation, increased angiotensin II levels, abnormal appetite regulation and impaired microRNA responses. Inflammation stimulates cellular signalling pathways that activate myostatin, which accelerates UPS-mediated catabolism. Blocking this pathway can prevent loss of muscle proteins. Myostatin inhibition could yield new therapeutic directions for blocking muscle protein wasting in CKD or disorders associated with its complications.

Epidemiology, contributors to, and clinical trials of mortality risk in chronic kidney failure

Patients with chronic kidney failure--defined as a glomerular filtration rate persistently below 15 mL/min per 1·73 m(2)--have an unacceptably high mortality rate. In developing countries, mortality results primarily from an absence of access to renal replacement therapy. Additionally, cardiovascular and non-cardiovascular mortality are several times higher in patients on dialysis or post-renal transplantation than in the general population. Mortality of patients on renal replacement therapy is affected by a combination of socioeconomic factors, pre-existing medical disorders, renal replacement treatment modalities, and kidney failure itself. Characterisation of the key pathophysiological contributors to increased mortality and cardiorenal risk staging systems are needed for the rational design of clinical trials aimed at decreasing mortality. Policy changes to improve access to renal replacement therapy should be combined with research into low-cost renal replacement therapy and optimum clinical care, which should include multifaceted approaches simultaneously targeting several of the putative contributors to increased mortality.

Renal consequences of parenteral nutrition

Parenteral nutrition (PN) can be described as the "Intravenous administration of nutrients necessary to sustain life in those who would otherwise have died or suffered serious disease". PN is indicated in children who cannot be fully fed by the oral or intestinal route, usually as a result of intestinal failure. Intradialytic parenteral nutrition (IDPN) is rarely indicated in children on dialysis and does not confer a benefit over enteral supplements in the compliant patient with adequate intestinal function. Renal and metabolic consequences of PN are potentially life-threatening and include disorders of glucose homeostasis, acid-base and fluid and electrolyte disturbances, nephrolithiasis, impaired renal function and metabolic bone disease. Many of these complications are avoidable. Adequate clinical and biochemical assessment and monitoring of children receiving PN by a multidisciplinary nutrition support team is recommended to mitigate against the risks of these complications.

A literature review of end-stage renal disease and cachexia: understanding experience to inform evidence-based healthcare

INTRODUCTION

Cachexia is a major cause of morbidity and mortality in people who have end-stage renal disease (ESRD). The majority of research into cachexia in ESRD has focused on the biological aspects of the syndrome and potential treatment modalities. While this research is necessary, it predominately focuses on the physical impact of cachexia in ESRD. The multi-dimensional psychosocial ramifications of this syndrome have been highlighted in other end-stage illness trajectories, but have not been systematically explored in persons who have ESRD.

AIM

This paper discusses why this research is necessary, alongside further studies to help define the pathophysiology of this syndrome.

CONCLUSION

The rich insightful data gained from understanding the patients' illness experience will positively contribute to the limited knowledge base available and inform future holistic patient-centred care delivery which recognises and responds to not only the biological but also the psychosocial impact of cachexia.

Long-term oral nutrition supplementation improves outcomes in malnourished patients with chronic kidney disease on hemodialysis

Background: There is no consensus on the type, time of initiation, or duration of use of enteral nutrition in patients with chronic kidney disease (CKD). This study aimed to compare the effects of a renal-specific oral nutrition supplement (RS-ONS) and a standard recommended nutrition regime on biochemical and nutrition markers in malnourished patients with CKD on hemodialysis. Methods: Sixty-two malnourished patients with CKD, divided into experimental (RS-ONS; n = 32; mean [SD] age, 62.0 [11.3] years; 55.2% female) and control (CON; n = 30; mean [SD] age, 57.2 [12.3] years; 31% female) groups, were evaluated for anthropometric, biochemical, and inflammatory parameters. Results: Mean (SD) serum albumin levels were significantly increased in the RS-ONS group from 3.5 (0.3) g/dL at baseline to 3.7 (0.2) g/dL at 6 months (P = .028). Significantly fewer patients had serum albumin levels of <3.5 g/dL after month 6. Dry weight of patients significantly increased in the RS-ONS but decreased in the CON groups (P < .001 for each). Percent change from baseline revealed negative results for bioelectrical impedance analysis (P < .001) in the CON group. Malnutrition inflammation score at 6 months (P = .006) and erythropoietin (EPO) dose requirements were higher in the CON group (P = .012). Conclusions: Our findings indicate that consuming RS-ONS improves serum albumin and anthropometric measures, as well as reduces EPO dose, in patients with CKD.

Muscle wasting in hemodialysis patients: new therapeutic strategies for resolving an old problem

Muscle wasting has long been recognized as a major clinical problem in hemodialysis (HD) patients. In addition to its impact on quality of life, muscle wasting has been proven to be associated with increased mortality rates. Identification of the molecular mechanisms underlying muscle wasting in HD patients provides opportunities to resolve this clinical problem. Several signaling pathways and humeral factors have been reported to be involved in the pathogenic mechanisms of muscle wasting in HD patients, including ubiquitin-proteasome system, caspase-3, insulin/insulin-like growth factor-1 (IGF-1) signaling, endogenous glucocorticoids, metabolic acidosis, inflammation, and sex hormones. Targeting the aforementioned crucial signaling and molecules to suppress protein degradation and augment muscle strength has been extensively investigated in HD patients. In addition to exercise training, administration of megestrol acetate has been proven to be effective in improving anorexia and muscle wasting in HD patients. Correction of metabolic acidosis through sodium bicarbonate supplements can decrease muscle protein degradation and hormone therapy with nandrolone decanoate has been reported to increase muscle mass. Although thiazolidinedione has been shown to improve insulin sensitivity, its role in the treatment of muscle wasting remains unclear. This review paper focuses on the molecular pathways and potential new therapeutic approaches to muscle wasting in HD patients.

Effects of a six-month intradialytic physical ACTIvity program and adequate NUTritional support on protein-energy wasting, physical functioning and quality of life in chronic hemodialysis patients: ACTINUT study protocol for a randomised controlled trial

BACKGROUND

Protein-energy wasting (PEW) is common in hemodialysis patients and is a powerful predictor of morbidity and mortality. Although much progress has been made in recent years in identifying the causes and pathogenesis of PEW in hemodialysis patients, actual management by nutritional interventions is not always able to correct PEW. Some investigators suggest that physical exercise may increase the anabolic effects of nutritional interventions, and therefore may have a potential to reverse PEW. The aim of this study is to investigate the effect of intra-dialytic progressive exercise training and adequate nutritional supplementation on markers of PEW, functional capacities and quality of life of adult hemodialysis patients.

METHODS AND DESIGN

Fifty end-stage renal disease patients undergoing hemodialysis, who meet the diagnostic criteria for PEW, will be randomly allocated into an exercise or control group for 6 months. The exercise consists of a progressive submaximal individualized cycling exertion using an adapted cycle ergometer, during the three weekly dialysis sessions. Biological markers of nutrition (albumin, prealbumin) will be followed monthly and all patients will be assessed for body composition, walk function, muscle strength, postural stability and quality of life at baseline and during the eighth week (t+2), the sixteenth week (t+4) and the twenty-fourth week (t+6) of the 6-month adapted rehabilitation program.

DISCUSSION

The successful completion of this current trial may give precious clues in understanding PEW and encourage nephrologists to extend prescription of exercise programs as well as therapeutic and as preventive interventions in this high-risk population.

TRIAL REGISTRATION

The protocol for this study was registered with the France Clinical Trials Registry NCT01813851.

Nutrition: Intradialytic oral nutrition--the ultimate conviction

Protein-energy wasting occurs frequently during maintenance dialysis. Known aetiologies include a loss of nutrients during the haemodialysis procedure and anorexia. Providing energy and protein during dialysis improves metabolism; however, the benefits of long-term support are debated. Weiner and colleagues report convincing data with an intradialytic oral nutritional intervention using protein supplements.

Spironolactone reduces cardiovascular and cerebrovascular morbidity and mortality in hemodialysis patients

OBJECTIVES

This study sought to assess whether spironolactone treatment reduces the high incidence of cardiovascular and cerebrovascular (CCV) morbidity and mortality in hemodialysis (HD) patients.

BACKGROUND

Aldosterone receptor blockers reduce cardiac-related events, but the efficacy of the agents in HD patients is unclear.

METHODS

A 3-year randomized trial involving 5 clinics was performed. Of the 309 oligoanuric HD patients enrolled in the study, 157 patients were randomly assigned to receive 25 mg/day of spironolactone without any restriction on dietary potassium intake (treatment group), and 152 patients were assigned to a control group. The primary outcome was a composite of death from CCV events or hospitalization for CCV events, and the secondary outcome was death from all causes.

RESULTS

During the 3-year follow-up, the primary outcome occurred in 5.7% of patients in the treatment group and in 12.5% of patients in the control group. Hazard ratios (HRs) for the primary outcome for treatment were 0.404 (95% confidence interval [CI]: 0.202 to 0.809; p = 0.017) and 0.379 (95% CI: 0.173 to 0.832; p = 0.016) before and after adjustment, respectively. The secondary outcome was significantly reduced in the treatment group compared with the control group (6.4% vs. 19.7%; HRs: 0.355 [95% CI: 0.191 to 0.662; p = 0.002] and 0.335 [95% CI: 0.162 to 0.693; p = 0.003] before and after adjustment, respectively). Gynecomastia or breast pain was reported in 16 patients (10.2%) in the treatment group. Serious hyperkalemia led to treatment discontinuation in 3 patients (1.9%).

CONCLUSIONS

Aldosterone receptor blockade using spironolactone may substantially reduce the risk of both CCV morbidity and death among HD patients; however, larger-scale studies are recommended to further confirm its efficacy. (Effects of Spironolactone on Cardio- and Cerebrovascular Morbidity and Mortality in Hemodialysis Patients; NCT01687699).

A patient with CKD and poor nutritional status

Protein energy wasting is common in patients with CKD and ESRD and is associated with adverse clinical outcomes, such as increased rates of hospitalization and death, in these patients. A multitude of factors can affect the nutritional and metabolic status of patients with CKD, including decreased dietary nutrient intake, catabolic effects of renal replacement therapy, systemic inflammation, metabolic and hormonal derangements, and comorbid conditions (such as diabetes and depression). Unique aspects of CKD also confound reliable assessment of nutritional status, further complicating management of this comorbid condition. In patients in whom preventive measures and oral dietary intake from regular meals cannot help them maintain adequate nutritional status, nutritional supplementation, administered orally, enterally, or parenterally, is effective in replenishing protein and energy stores. The advantages of oral nutritional supplements include proven efficacy, safety, and compliance. Anabolic steroids and exercise, with nutritional supplementation or alone, improve protein stores and represent potential additional approaches for the treatment of PEW. There are several emerging novel therapies, such as appetite stimulants, anti-inflammatory interventions, and anabolic agents.

Low protein nitrogen appearance as a surrogate of low dietary protein intake is associated with higher all-cause mortality in maintenance hemodialysis patients

To determine the association between all-cause mortality and dietary protein intake in patients with chronic kidney disease, we performed a large-scale, 8-y prospective cohort study in 98,489 maintenance hemodialysis patients from a multicenter dialysis care provider. Compared with the reference level (60 to <70 g/d), low protein nitrogen appearance (PNA) levels [<30 g/d, HR: 1.40 (95% CI: 1.30, 1.50); 30 to <40 g/d, HR: 1.33 (95% CI: 1.28, 1.39)] was associated with higher all-cause mortality, and high PNA levels [≥110 g/d, HR: 0.92 (95% CI: 0.88, 0.97); 100 to <110 g/d, HR: 0.87 (95% CI: 0.82, 0.91)] were associated with lower all-cause mortality in all analyses. This association was also found in subanalyses performed among racial and hypoalbuminemic groups. Hence, using PNA as a surrogate for protein intake, a low daily dietary protein intake is associated with increased risk of death in all hemodialysis patients. Whether the association between dietary protein intake and survival is causal or a consequence of anorexia secondary to protein-energy-wasting/inflammation or other factors should be explored in interventional trials.

Management of protein-energy wasting in non-dialysis-dependent chronic kidney disease: reconciling low protein intake with nutritional therapy

Protein-energy wasting (PEW), characterized by a decline in body protein mass and energy reserves, including muscle and fat wasting and visceral protein pool contraction, is an underappreciated condition in early to moderate stages of chronic kidney disease (CKD) and a strong predictor of adverse outcomes. The prevalence of PEW in early to moderate CKD is ≥20-25% and increases as CKD progresses, in part because of activation of proinflammatory cytokines combined with superimposed hypercatabolic states and declines in appetite. This anorexia leads to inadequate protein and energy intake, which may be reinforced by prescribed dietary restrictions and inadequate monitoring of the patient's nutritional status. Worsening uremia also renders CKD patients vulnerable to potentially deleterious effects of uncontrolled diets, including higher phosphorus and potassium burden. Uremic metabolites, some of which are anorexigenic and many of which are products of protein metabolism, can exert harmful effects, ranging from oxidative stress to endothelial dysfunction, nitric oxide disarrays, renal interstitial fibrosis, sarcopenia, and worsening proteinuria and kidney function. Given such complex pathways, nutritional interventions in CKD, when applied in concert with nonnutritional therapeutic approaches, encompass an array of strategies (such as dietary restrictions and supplementations) aimed at optimizing both patients' biochemical variables and their clinical outcomes. The applicability of many nutritional interventions and their effects on outcomes in patients with CKD with PEW has not been well studied. This article reviews the definitions and pathophysiology of PEW in patients with non-dialysis-dependent CKD, examines the current indications for various dietary modification strategies in patients with CKD (eg, manufactured protein-based supplements, amino acids and their keto acid or hydroxyacid analogues), discusses the rationale behind their potential use in patients with PEW, and highlights areas in need of further research.