A randomized pilot trial of oral branched-chain amino acids in early cirrhosis: validation using prognostic markers for pre-liver transplant status

Branched-Chain Amino Acids in Liver Diseases: Complexity and Controversy

Branched-chain amino acids (BCAAs), as essential amino acids, engage in various physiological processes, such as protein synthesis, energy supply, and cellular signaling. The liver is a crucial site for BCAA metabolism, linking the changes in BCAA homeostasis with the pathogenesis of a variety of liver diseases and their complications. Peripheral circulating BCAA levels show complex trends in different liver diseases. This review delineates the alterations of BCAAs in conditions including non-alcoholic fatty liver disease, hepatocellular carcinoma, cirrhosis, hepatic encephalopathy, hepatitis C virus infection, and acute liver failure, as well as the potential mechanisms underlying these changes. A significant amount of clinical research has utilized BCAA supplements in the treatment of patients with cirrhosis and liver cancer. However, the efficacy of BCAA supplementation in clinical practice remains uncertain and controversial due to the heterogeneity of studies. This review delves into the complicated relationship between BCAAs and liver diseases and tries to untangle what role BCAAs play in the occurrence, development, and outcomes of liver diseases.

Use of Branched-Chain Amino Acids as a Potential Treatment for Improving Nutrition-Related Outcomes in Advanced Chronic Liver Disease

Advanced chronic liver disease (ACLD) represents a complex and multifactorial clinical entity characterized by liver dysfunction and associated complications. In recent years, the significance of nutritional status in ACLD prognosis has gained considerable attention. This review article delves into the multifactorial pathogenesis of malnutrition in ACLD and its profound consequences for health outcomes. We explore the clinical implications of secondary sarcopenia in ACLD and highlight the critical relevance of frailty in both decompensated and compensated ACLD. A specific focus of this review revolves around branched-chain amino acids (BCAAs) and their pivotal role in managing liver disease. We dissect the intricate relationship between low Fischer's ratio and BCAA metabolism in ACLD, shedding light on the molecular mechanisms involved. Furthermore, we critically evaluate the existing evidence regarding the effects of BCAA supplementation on outcomes in ACLD patients, examining their potential to ameliorate the nutritional deficiencies and associated complications in this population.

Branched-chain amino acids supplementation improves liver frailty index in frail compensated cirrhotic patients: a randomized controlled trial

BACKGROUND

Physical frailty is related with morbidity and mortality in patients with cirrhosis. Currently, there is no approved treatment of frailty in these patients. Here, we evaluated the efficacy of 16 weeks branched-chain amino acids (BCAA) supplementation on frailty in frail compensated cirrhotic patients.

METHODS

After a 4-week run-in period consisted of dietary and exercise counseling, compensated cirrhotic patients with frailty, defined by liver frailty index (LFI)≥4.5, were randomly assigned (1:1) to BCAA or control group. The BCAA group received twice daily BCAAs supplementation (210 kcal, protein 13.5 g, BCAA 2.03 g) for 16 weeks. The primary outcome was frailty reversion. The secondary outcomes were changes in biochemistries, body composition evaluated by bioelectrical impedance analysis, and quality of life (QoL).

RESULTS

54 patients were prospectively enrolled (age 65.5 ± 9.9 years, 51.9% female, Child-Pugh A/B 68.5%/31.5%, MELD 10.3 ± 3.1). Baseline characteristics were similar between both groups. At week 16, BCAA group had a significant improvement in LFI (-0.36 ± 0.3 vs. -0.15 ± 0.28, P = 0.01), BMI (+ 0.51 ± 1.19 vs. -0.49 ± 1.89 kg/m², P = 0.03), and serum albumin (+ 0.26 ± 0.27 vs. +0.06 ± 0.3 g/dl, P = 0.01). The proportion of frailty reversion at week 16 was significantly higher in BCAA group (36% vs. 0%, P < 0.001). Compared with baseline, BCAA group had a significant increase in skeletal muscle index (7.5 ± 1.6 to 7.8 ± 1.5 kg/m², P = 0.03). Regarding the QoL, only the BCAA group had a significant improvement in all 4 domains of physical component score of the SF-36 questionnaire.

CONCLUSIONS

A 16-week BCAA supplementation improved frailty in frail compensated cirrhotic patients. In addition, this intervention resulted in an improvement of muscle mass and physical domain of QoL in these patients.

TRIAL REGISTRATION

This study was registered with Thai Clinical Trial Registry (TCTR20210928001; https://www.thaiclinicaltrials.org/# ).

Systematic review with meta-analysis: Branched-chain amino acid supplementation in liver disease

BACKGROUND

Dietary supplementation with branched-chain amino acids (BCAA) is often used in cirrhotic patients to improve nutritional status. We wanted to explore the evidence for BCAA supplementation in chronic liver disease.

METHODS

We searched MEDLINE and EMBASE for studies with BCAA supplementation with the presence of a disease-control group (placebo or no intervention) using search terms 'liver cirrhosis', 'hepatocellular carcinoma', 'branched chain amino acids' and relevant synonyms. Risk of bias was assessed using ROBINS-I and RoB 2.0 tools. Meta-analyses were performed with a random-effects model. Results were reported following EQUATOR guidelines.

RESULTS

Of 3378 studies screened by title and abstract, 54 were included (34 randomized controlled trials, 5 prospective case-control studies, 13 retrospective case-control studies: in total 2308 patients BCAA supplementation, 2876 disease-controls). Risk of bias was high/serious for almost all studies. According to meta-analyses, long-term (at least 6 months) BCAA supplementation in cirrhotic patients significantly improved event-free survival (p = .008; RR .61 95% CI .42-.88) and tended to improve overall survival (p = .05; RR .58 95% CI .34-1.00). Two retrospective studies suggested the beneficial effects during sorafenib for hepatocellular carcinoma. Available studies reported no beneficial effects or contradictory results of BCAA after other specific therapeutic interventions (resection or radiological interventions for hepatocellular carcinoma, liver transplantation, paracentesis or variceal ligation). No convincing beneficial effects of BCAA supplementation on liver function, nutritional status or quality of life were found. No study reported serious side effects of BCAA.

CONCLUSIONS

Prophylactic BCAA supplementation appears safe and might improve survival in cirrhotic patients.

Effect of dietary branched chain amino acids on liver related mortality: Results from a large cohort of North American patients with advanced HCV infection

Branched chain amino acids (BCAA) supplementation may reduce the incidence of liver failure and hepatocellular carcinoma in patients with cirrhosis. We aimed to determine whether long-term dietary intake of BCAA is associated with liver-related mortality in a well-characterized cohort of North American patients with advanced fibrosis or compensated cirrhosis. We performed a retrospective cohort study using extended follow-up data from the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial. The analysis included 656 patients who completed two Food Frequency Questionnaires. The primary exposure was BCAA intake measured in grams (g) per 1000 kilocalories (kcal) of energy intake (range 3.0-34.8 g/1000 kcal). During a median follow-up of 5.0 years, the incidence of liver-related death or transplantation was not significantly different among the four quartiles of BCAA intake before and after adjustment of confounders (AHR 1.02, 95% CI 0.81-1.27, P-value for trend = 0.89). There remains no association when BCAA was modeled as a ratio of BCAA to total protein intake or as absolute BCAA intake. Finally, BCAA intake was not associated with the risk of hepatocellular carcinoma, encephalopathy or clinical hepatic decompensation. We concluded that dietary BCAA intake was not associated with liver-related outcomes in HCV-infected patients with advanced fibrosis or compensated cirrhosis. The precise effect of BCAA in patients with liver disease warrants further study.

Branched-chain amino acids supplementation has beneficial effects on the progression of liver cirrhosis: A meta-analysis

BACKGROUND

Liver cirrhosis (LC) is currently the 11^th most common cause of death and 15^th cause of morbidity globally. The treatment of LC is mainly aimed at etiological intervention, lifestyle intervention, prevention and treatment of complications and nutritional treatment. Nutritional treatment of LC mainly includes increasing dietary intake, food intake time and branched-chain amino acids (BCAAs). Despite the recommendation of BCAAs in some guidelines, adverse effects have been reported in studies so the efficacy and safety of BCAAs remain controversial. Currently, BCAAs have been widely used in chronic liver disease, while the summary of the effect of BCAAs on long-term prognosis is rare.

AIM

To determine the effects of BCAAs in patients with LC.

METHODS

The PubMed, Cochrane Library, Embase and Web of Science databases were searched. The retrieval deadline was 1 October 2021 and there were no language restrictions set in the retrieval. The study was performed in strict accordance with the inclusion and exclusion criteria. Nine studies were finally included. The primary outcome was complications of LC. The secondary outcomes were nutritional status and liver function. This meta-analysis used the Review Manager, version 5 statistical package (Cochrane Collaboration, Oxford, England) for analysis.

RESULTS

The analysis included nine studies that consisted of 1080 patients (554 in the BCAA groups and 526 in the control groups). The nine studies were randomized control trials (RCTs). The quality of the studies was assessed using the risk of bias method recommended by the Cochrane Collaboration. BCAAs reduced the rate of complications in LC patients [Risk ratio: 0.70, 95% confidence interval (CI): 0.56-0.88, P = 0.002] and improved patients’ albumin levels [std mean difference SMD: 0.26, 95%CI: 0.12-0.40, P = 0.0002]. Meanwhile, BCAAs significantly ameliorated the levels of alanine transaminase (SMD: -2.03, 95%CI: -2.52 to -1.53, P < 0.00001) and aspartate aminotransferase (SMD: -1.8, 95%CI: -2.14 to -1.46, P < 0.00001). Meanwhile, glucose in the LC was significantly increased in BCAA-treated patients (MD: 13.04, 95%CI: 6.81-19.89, P = 0.0002).

CONCLUSION

BCAAs reduce the incidence of complications in patients with LC and ameliorate nutritional status.

Therapeutic mechanisms and beneficial effects of non-antidiabetic drugs in chronic liver diseases

The global burden of chronic liver disease (CLD) is substantial. Due to the limited indication of and accessibility to antiviral therapy in viral hepatitis and lack of effective pharmacological treatment in nonalcoholic fatty liver disease, the beneficial effects of antidiabetics and non-antidiabetics in clinical practice have been continuously investigated in patients with CLD. In this narrative review, we focused on non-antidiabetic drugs, including ursodeoxycholic acid, silymarin, dimethyl4,4'-dimethoxy-5,6,5',6'-dimethylenedixoybiphenyl-2,2'-dicarboxylate, L-ornithine L-aspartate, branched chain amino acids, statin, probiotics, vitamin E, and aspirin, and summarized their beneficial effects in CLD. Based on the antioxidant, anti-inflammatory properties, and regulatory functions in glucose or lipid metabolism, several non-antidiabetic drugs have shown beneficial effects in improving liver histology, aminotransferase level, and metabolic parameters and reducing risks of hepatocellular carcinoma and mortality, without significant safety concerns, in patients with CLD. Although the effect as the centerpiece management in patients with CLD is not robust, the use of these non-antidiabetic drugs might be potentially beneficial as an adjuvant or combined treatment strategy.

Adding Branched-Chain Amino Acids to an Enhanced Standard-of-Care Treatment Improves Muscle Mass of Cirrhotic Patients With Sarcopenia: A Placebo-Controlled Trial

INTRODUCTION

The effect of branched-chain amino acid (BCAA) supplementation on muscle mass in patients with cirrhosis and sarcopenia is unknown.

METHODS

This is a pilot, prospective, randomized, and double-blind study of a cohort of 32 patients with cirrhosis and sarcopenia diagnosed by computed tomography scan who underwent a nutritional and physical activity intervention for 12 weeks. They were divided into 2 groups (placebo: 17 patients; BCAA: 15 patients). The study protocol was registered at ClinicalTrials.gov (NCT04073693).

RESULTS

Baseline characteristics were similar in both groups. After treatment, only the BCAA group presented a significant improvement in muscle mass (43.7 vs 46 cm2/m2; P = 0.023). Seventeen patients (63%) presented improvement in muscle mass overall, which was more frequent in the BCAA group (83.3 vs 46.7%; P = 0.056). Regarding frailty, there was a significant improvement in the Liver Frailty Index in the global cohort (n = 32) after the 12 weeks (4.2 vs 3.9; P < 0.001). This difference was significant in both groups: in the placebo group (4.2 vs 3.8; P < 0.001) and in the BCAA group (4.2 vs 3.9; P < 0.001). After treatment, the BCAA group had a higher increase in zinc levels than the placebo group (Δzinc: 12.3 vs 5.5; P = 0.026). In addition, there was a trend for greater improvement of albumin levels in the BCAA group (Δalbumin: 0.19 vs 0.04; P = 0.091).

DISCUSSION

BCAA supplementation improves muscle mass in cirrhotic patients with sarcopenia.

The impact of L-branched-chain amino acids and L-leucine on malnutrition, sarcopenia, and other outcomes in patients with chronic liver disease

INTRODUCTION

Metabolic and hormonal disorders resulting from chronic liver diseases culminate in increased proteolysis and decreased protein synthesis, which contributes to the development and progression of malnutrition and, consequently, sarcopenia. Nutritional management of sarcopenia in liver cirrhosis is a continuously evolving field and data on essential amino acid supplementation in chronic liver diseases is scarce.

AREAS COVERED

This review encompasses the current literature on oral amino acids supplementation in patients with chronic liver disease or patients with liver cirrhosis to try to elucidate the possible effects of L-branched-chain amino acids and isolated L-leucine as a therapeutic approach to malnutrition and sarcopenia.

EXPERT COMMENTARY

To ensure an optimal nutritional status and to reduce sarcopenia, it is necessary to assess nutritional status in all patients with liver cirrhosis and to apply nutritional interventions accordingly. The supply of calories, proteins, and essential amino acids is necessary for the maintenance of muscle mass and function. Although supplementation of L-branched-chain amino acids plays an important role in liver disease, L-leucine has been described as the main amino acid involved in protein turnover, reducing proteolysis, and stimulating protein synthesis.

Nutritional support in cirrhotic patients with sarcopenia

Sarcopenia has been linked to oncologic and chronic diseases such as liver cirrhosis. In fact, sarcopenia is present in 25-70% of patients with liver cirrhosis. Furthermore, sarcopenia is an independent predictor of poor prognosis in many diseases. Currently cirrhotic patients are recommended to adopt a high protein diet (1.5 g/kg/day) with 30-40 kcal/kg/day and several meals throughout the day, being late evening snack intake with at least 50 g of carbohydrates of special importance. Despite the growing interest in the impact of sarcopenia in cirrhotic patients, there are still gaps in knowledge in the appropriate diagnostic criteria for this syndrome, the role of gut microbiota, as well as the most appropriate nutritional therapy.

Influence of gut microbiota and intestinal barrier on enterogenic infection after liver transplantation

Liver transplantation is currently a standard therapy for patients with end-stage liver diseases and hepatocellular carcinoma. Given that liver transplantation has undergone a thriving development in these decades, the survival rates after liver transplantation have markedly improved as a result of the critical advancement in surgical techniques, immunosuppressive therapies, and post-operative care. However, infection remains a fatal complication after liver transplantation surgery. In particular, enterogenic infection represents a major complication in liver transplant recipients. This article gives an overview of infection cases after liver transplantation and focuses on the discussion of enterogenic infection in terms of its pathophysiology, risk factor, outcome, and treatment.

Dietary management and supplementation with branched-chain amino acids in cirrhosis of the liver

One of the most important characteristics of malnutrition is the loss of muscle mass and the severe depletion of the protein reserve, secondarily affecting energy metabolism. That impacts nutritional status and the progression of disease-related complications. Nutritional treatment is one of the main factors in the comprehensive management of those patients. Achieving adequate energy intake that provides the macronutrients and micronutrients necessary to prevent or correct malnutrition is attempted through dietary measures. ESPEN, the European Society for Clinical Nutrition and Metabolism, recommends a caloric intake of 30-40kcal/kg/day, in which carbohydrates provide 45-60% of the daily energy intake and proteins supply 1.0-1.5g/kg/day. The remaining portion of the total energy expenditure should be covered by lipids. The administration of branched-chain amino acids has been shown to be beneficial not only in counteracting malnutrition, but also as a coadjuvant treatment in specific complications, thus playing a favorable role in outcome and quality of life. Therefore, branched-chain amino acids should be considered part of nutritional treatment in patients with advanced stages of cirrhosis of the liver, particularly in the presence of complications.

Dietary Interventions in Liver Cirrhosis

Liver cirrhosis is associated with significant nutritional risks that often result in serious hepatic complications and poor survival rates. Diet is an important but underutilized aspect in the treatment modality of cirrhosis. Therefore, the aims of this review are to ascertain nutritional risks associated with its pathophysiology and to summarize existing evidence that support dietary recommendations for managing this patient population. Alterations in substrate utilization for energy production is a main feature of liver cirrhosis, resulting in increased catabolism of protein stores and a predisposition toward protein-energy malnutrition, even in the early stages of the disease. The body of evidence suggests that a high energy and protein (>1.2 g/kg body weight/d) diet consumed frequently and late in the evening is effective in improving nutritional status of these patients and has been associated with improved hospitalization and mortality rates. The use of branched-chain amino acid supplementation shows promise in reducing cirrhosis-related complications but are currently limited by adverse gastrointestinal symptoms and poor palatability. Furthermore exploration of dietary manipulation of branched-chain amino acid warrants further examination. Evidence is also accumulating that protein intake should not be restricted in patients with hepatic encephalopathy with earlier studies of protein restriction neglecting to account for the relative increase in fermentable fiber which would reduce the absorption of ammonia into the portal system in a way similar to supplementation with lactulose. Finally, a major finding of this review is the need to improve the quality and quantity of dietary intervention studies for patients with liver cirrhosis, particularly with the use of partial or whole dietary sources. In conclusion, dietary management of cirrhosis is not a one-size fits all approach but should be implemented earlier on in the treatment algorithm to improve the clinical prognosis of cirrhosis.

Effects of branched chain amino acid supplementation on patient care outcomes in adults and children with liver cirrhosis: A systematic review

BACKGROUND & AIMS

Malnutrition is highly prevalent in chronic liver disease (CLD) due to alterations in nutrient utilization, malabsorption and poor intake. Low serum concentrations of branched chain amino acids (BCAA) in the presence of elevated aromatic acid concentrations is commonly observed in adult and children with liver cirrhosis and is associated with malnutrition and other adverse patient outcomes. The efficacy of BCAA supplementation has not been well established in adults and children with CLD. The purpose of this review was to critically evaluate the literature regarding the impact of BCAA supplementation related to changes in body composition, muscle strength, liver biomarkers, medical and hepatic complications (hepatic encephalopathy (HE), ascites, edema) and patient care outcomes (event free survival, health related quality of life, length of hospitalization).

METHODS

A total of 40 articles retrieved from PubMed or Web of Science databases (1989-2017) were included.

RESULTS

BCAA supplementation may be beneficial in improving muscle strength, ascites and edema with potential clinically significant improvements in HE in adult liver patients. In children, limited data have shown that BCAA supplementation may exert favourable effects on weight, fat mass, fat free mass and serum albumin level.

CONCLUSIONS

Heterogeneity of study findings attributed to variability in BCAA dose (total, relative proportions), duration, disease severity and lack of uniformity in tools used for assessing patient outcomes limit overall conclusions. Longitudinal studies examining the efficacy of BCAA supplementation as a therapeutic treatment of malnutrition in chronic liver disease is warranted.

Exercise and physical activity for patients with end-stage liver disease: Improving functional status and sarcopenia while on the transplant waiting list

Sarcopenia and physical deconditioning are frequent complications in patients with cirrhosis and end-stage liver disease (ESLD). They are the end result of impaired dietary intake, chronic inflammation, altered macronutrient and micronutrient metabolism, and low physical activity. Frailty is the end result of prolonged sarcopenia and physical deconditioning. It severely affects a patient's functional status and presents in approximately 1 in 5 patients on the liver transplantation waiting list. Sarcopenia, poor physical fitness/cardiopulmonary endurance (CPE), and frailty are all associated with increased mortality in ESLD. Clinical trials addressing the usefulness of exercise in patients with cirrhosis have shown that it improves the metabolic syndrome, sarcopenia, CPE, health-related quality of life, and hepatic venous pressure gradient. Although evidence on the benefits of exercise on clinical outcomes derived from large clinical trials is still missing, based on existing literature from multiple medical subspecialties, we believe that an exercise program coupled to a tailored nutritional intervention benefits both cardiopulmonary and musculoskeletal functions, ultimately translating into improved functional status, sense of well-being, and possibly less complications from portal hypertension. In conclusion, although supervised exercise training is the prevailing approach to manage ESLD patients, such intervention is not sustainable or feasible for most patients. Innovative home-based physical activity interventions may be able to effectively reach a larger number of patients. Liver Transplantation 24 122-139 2018 AASLD.

Nutritional Therapy in Liver Transplantation

Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease who undergo liver transplantation. Malnutrition may further increase morbidity, mortality and costs in the post-transplantation setting. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognized. The metabolic abnormalities induced by liver failure render the conventional assessment of nutritional status to be challenging. Preoperative loss of skeletal muscle mass, namely, sarcopenia, has a significant detrimental impact on post-transplant outcomes. It is essential to provide sufficient nutritional support during all phases of liver transplantation. Oral nutrition is preferred, but tube enteral nutrition may be required to provide the needed energy intake. Herein, the latest currently employed perioperative nutritional interventions in liver transplant recipients are thoroughly illustrated including synbiotics, micronutrients, branched-chain amino acid supplementation, immunonutrition formulas, fluid and electrolyte balance, the offering of nocturnal meals, dietary counselling, exercise and rehabilitation.

Plasma Amino Acid Concentrations Predict Mortality in Patients with End-Stage Liver Disease

BACKGROUND

The liver plays a key role in amino acid metabolism. In former studies, a ratio between branched-chain and aromatic amino acids (Fischer's ratio) revealed associations with hepatic encephalopathy. Furthermore, low concentrations of branched-chain amino acids were linked to sarcopenia in literature. Encephalopathy and sarcopenia are known to dramatically worsen the prognosis. Aim of this study was to investigate a complex panel of plasma amino acids in the context of mortality in patients with end-stage liver disease.

METHODS

166 patients evaluated for orthotopic liver transplantation were included. 19 amino acids were measured from citrated plasma samples using mass spectrometry. We performed survival analysis for plasma amino acid constellations and examined the relationship to established mortality predictors.

RESULTS

33/166 (19.9%) patients died during follow-up. Lower values of valine (p<0.001), Fischer's ratio (p<0.001) and valine to phenylalanine ratio (p<0.001) and higher values of phenylalanine (p<0.05) and tyrosine (p<0.05) were significantly associated with mortality. When divided in three groups, the tertiles discriminated cumulative survival for valine (p = 0.016), phenylalanine (p = 0.024) and in particular for valine to phenylalanine ratio (p = 0.003) and Fischer's ratio (p = 0.005). Parameters were also significantly correlated with MELD and MELD-Na score.

CONCLUSIONS

Amino acids in plasma are valuable biomarkers to determine increased risk of mortality in patients with end-stage liver disease. In particular, valine concentrations and constellations composed of branched-chain and aromatic amino acids were strongly associated with prognosis. Due to their pathophysiological importance, the identified amino acids could be used to examine individual dietary recommendations to serve as potential therapeutic targets.

Evidence-based clinical practice guidelines for liver cirrhosis 2015

The Japanese Society of Gastroenterology revised the evidence-based clinical practice guidelines for liver cirrhosis in 2015. Eighty-three clinical questions were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases for the period between 1983 and June 2012. Manual searching of the latest important literature was added until August 2015. The guidelines were developed with use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. This digest version in English introduces selected clinical questions and statements related to the management of liver cirrhosis and its complications. Branched-chain amino acids relieve hypoalbuminemia and hepatic encephalopathy and improve quality of life. Nucleoside analogues and peginterferon plus ribavirin combination therapy improve the prognosis of patients with hepatitis B virus related liver cirrhosis and hepatitis C related compensated liver cirrhosis, respectively, although the latter therapy may be replaced by direct-acting antivirals. For liver cirrhosis caused by primary biliary cirrhosis and active autoimmune hepatitis, urosodeoxycholic acid and steroid are recommended, respectively. The most adequate modalities for the management of variceal bleeding are the endoscopic injection sclerotherapy for esophageal varices and the balloon-occluded retrograde transvenous obliteration following endoscopic obturation with cyanoacrylate for gastric varices. Beta-blockers are useful for primary prophylaxis of esophageal variceal bleeding. The V2 receptor antagonist tolvaptan is a useful add-on therapy in careful diuretic therapy for ascites. Albumin infusion is useful for the prevention of paracentesis-induced circulatory disturbance and renal failure. In addition to disaccharides, the nonabsorbable antibiotic rifaximin is useful for the management of encephalopathy. Anticoagulation therapy is proposed for patients with acute-onset or progressive portal vein thrombosis.

Identification of key metabolic changes in renal interstitial fibrosis rats using metabonomics and pharmacology

Renal fibrosis is one of the important pathways involved in end-stage renal failure. Investigating the metabolic changes in the progression of disease may enhance the understanding of its pathogenesis and therapeutic information. In this study, (1)H-nuclear magnetic resonance (NMR)-based metabonomics was firstly used to screen the metabolic changes in urine and kidney tissues of renal interstitial fibrotic rats induced by unilateral ureteral obstruction (UUO), at 7, 14, 21, and 28 days after operation, respectively. The results revealed that reduced levels of bioenergy synthesis and branched chain amino acids (BCAAs), as well as elevated levels of indoxyl sulfate (IS) are involved in metabolic alterations of renal fibrosis rats. Next, by pharmacological treatment we found that reduction of IS levels could prevent the renal fibrotic symptoms. Therefore, we suggested that urinary IS may be used as a potential biomarker for the diagnosis of renal fibrosis, and a therapeutic target for drugs. Novel attempt combining metabonomics and pharmacology was established that have ability to provide more systematic diagnostic and therapeutic information of diseases.

Branched-chain amino acid supplementation in adults with cirrhosis and porto-systemic encephalopathy: systematic review

BACKGROUND & AIMS

Branched-chain amino acid supplementation in porto-systemic encephalopathy remains controversial. Here, we examined the systematic review evidence for their effect on encephalopathy, hepatic decompensation, survival, infection, hospital stay and quality of life, and review data on adherence, side-effects and cost/economic evaluation.

METHODS

Four electronic databases were searched from 1980 to June 2011, with an update search in two databases in July 2013. Hand-searching was performed of references lists from included trials and six conference proceedings from 2005 to 2010. We included randomised controlled trials of branched chain amino acids versus other nutritional supplements in adults with cirrhosis and porto-systemic encephalopathy. Data extraction and quality assessment were performed by two independent assessors. Meta-analysis was performed if data were sufficient.

RESULTS

The search identified nine randomised controlled trials (436 patients in total) of branched-chain amino acid therapy for ≥2 weeks' duration. The overall quality of trials was poor. At meta-analysis, a significant improvement in the grade of encephalopathy was demonstrated in favour of branched-chain amino acids compared to other nutritional supplements (Risk Ratio 2.6, 95% Confidence Interval 1.7-3.9, p < 0.001, 2 trials, n 122) but no significant difference was found for either resolution or worsening of encephalopathy, gastrointestinal bleeding, survival or infection. Limited data suggested no difference in health-related quality of life, ascites or admission to hospital. Studies did not include cost data or economic evaluations. Side-effects appeared mild and gastrointestinal in nature.

CONCLUSIONS

Branched-chain amino acids might improve porto-systemic encephalopathy but more robust trials are needed to determine their role.

Clinical significance of therapy using branched-chain amino acid granules in patients with liver cirrhosis and hepatocellular carcinoma

The liver is the major organ for the metabolism of protein, fat and carbohydrate. A nutritional approach is required in the treatment of cirrhosis, which is frequently complicated with protein-energy malnutrition. Several advanced treatment approaches for hepatocellular carcinoma (HCC) have been established in the past decade. HCC is often complicated by cirrhosis, so treatment of the underlying liver diseases is also necessary to improve the prognosis. Branched-chain amino acid (BCAA) granules were developed originally for the treatment of hypoalbuminemia associated with decompensated cirrhosis. However, subsequent studies found various other pharmacological actions of this agent. We review the clinical significance of therapy using BCAA granules in patients receiving different treatment approaches for cirrhosis and HCC based on the published work as well as our own data.

Perioperative nutritional therapy in liver transplantation

Protein-energy malnutrition is frequently seen in patients with end-stage liver disease who undergo liver transplantation. This causes a deterioration of the patients' clinical condition and affects their post-transplantation survival. Accurate assessment of the nutritional status and adequate intervention are prerequisites for perioperative nutritional treatment. However, the metabolic abnormalities induced by liver failure make the traditional assessment of the nutritional status difficult. The methods that were recently developed for accurately assessing the nutritional status by body bioelectrical impedance may be implemented in pre-transplant management. Because preoperative malnutrition and the loss of skeletal muscle mass, called sarcopenia, have a significant negative impact on the post-transplantation outcome, it is essential to provide adequate nutritional support during all phases of liver transplantation. Oral nutrition is preferred, but tube enteral nutrition may be required to provide the necessary caloric intake. We herein discuss both bioelectrical impedance and the latest findings in the current perioperative nutritional interventions in liver transplant patients regarding synbiotics, micronutrients, branched-chain amino acid supplementation, the use of immune system modulating formulas, the fluid balance and the offering of nocturnal meals.

Branched-chain amino acids in liver diseases

Branched chain amino acids (BCAAs) have been shown to affect gene expression, protein metabolism, apoptosis and regeneration of hepatocytes, and insulin resistance. They have also been shown to inhibit the proliferation of liver cancer cells in vitro, and are essential for lymphocyte proliferation and dendritic cell maturation. In patients with advanced chronic liver disease, BCAA concentrations are low, whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high, conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients. Based on these basic observations, patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines, with positive effects.

Effect of a carbohydrate-containing late-evening snack on energy metabolism and fasting substrate utilization in adults with acute-on-chronic liver failure due to Hepatitis B

BACKGROUND/OBJECTIVES

This study investigates the effects of a carbohydrate (CHO; lotus-root starch) predominant, late-evening snack (LES), containing 200 kcal (50 g CHO) on fasting resting energy expenditure (REE) and nutrient oxidation in hospitalized adults with acute-on-chronic liver failure (ACLF).

SUBJECTS/METHODS

Adults with ACLF were randomized to receive daily LES (treatment; n=35) or standard care (n=35; non-supplemented control) for 14 days. REE and respiratory quotient (RQ) were measured by indirect calorimetry, nutrient oxidation (CHO, protein and fat), intake and biochemical parameters were measured in both groups at baseline and after 14 days using validated techniques. Disease severity was measured using the model for end-stage liver disease (MELD).

RESULTS

No significant differences in macronutrient intake, anthropometric, demographic characteristics or MELD scores were observed between groups at baseline (P>0.05). Fasting RQ was significantly higher in the LES supplemented verses the control group after 2 weeks (P=0.02). CHO oxidation was significantly higher (P=0.001) and fat oxidation (P=0.02) was lower in the LES-supplemented group when compared with controls after 2 weeks. Fasting RQ and REE in the LES-supplemented group increased significantly (0.83 verses 0.88; P=0.007/1301±409 vs 1687±718 kcal/day; P=0.02) in patients with MELD scores 30 when compared with patients with MELD scores >30 (0.82 verses 0.84; P=0.27/ 1361±405 vs 1437±429 kcal/day; P=0.67) after supplementation.

CONCLUSIONS

A carbohydrate-predominant LES is associated with increases in fasting carbohydrate oxidation, REE and reductions in fat oxidation in adults with ACLF. Therapeutic strategies utilizing LES may promote improved nutritional status in adults with ACLF.

Effects of branched-chain amino acid granules on serum albumin level and prognosis are dependent on treatment adherence in patients with liver cirrhosis

AIM

To test if the treatment adherence to branched-chain amino acid (BCAA) granules influences the serum albumin level and prognosis in prospective 2984 patients with decompensated liver cirrhosis who were prescribed BCAA granules containing 952 mg of L-isoleucine, 1904 mg of L-leucine and 1144 mg of L-valine at 4.15 g/sachet three times a day after meals.

METHODS

The primary end-point was the time to the event defined as "hospital admission due to progression of hepatic failure", and factors affecting this outcome were explored. Changes in serum albumin level were evaluated as the secondary end-point.

RESULTS

Patients were divided into the good adherence group (those who reported to have taken "nearly all" prescribed doses) and the poor adherence group (those who reported to have taken "approximately half" or "less" doses), because such stratification was validated by treatment responses in plasma BCAA/tyrosine ratio. Factors related to the primary end-point were age, drug adherence during 6 months of study treatment, previous hepatic cancer, current clinical manifestations, previous clinical manifestations, baseline serum albumin level, platelet count and total bilirubin level. The cumulative event-free survival was significantly higher in the good adherence group. Increase in the serum albumin level was also greater in the good adherence group.

CONCLUSION

Higher BCAA treatment adherence better raised the serum albumin level, leading to improvement of event-free survival. These results indicate the importance of patient instruction for the adequate use of BCAA granules.

DNA microarray analysis identified molecular pathways mediating the effects of supplementation of branched-chain amino acids on CCl4-induced cirrhosis in rats

SCOPE

This study addresses the effects of branched-chain amino acids (BCAA) on global gene expression in liver and skeletal muscle and the molecular mechanisms underlying the improvement in liver cirrhosis using DNA microarray analysis combined with RNase protection assay.

METHODS AND RESULTS

Male Wistar rats administered carbon tetrachloride (CCl(4) ) repeatedly for 19 weeks as a decompensated cirrhosis model were thereafter given BCAA-enriched diet (AL) or normal diet (LC) for 5 weeks. The control-diet rats without CCl(4) administration were used as a normal control group. Gene expression in AL was reversed by twofold greater than in LC in the microarray were selected to elucidate the improvements in nutritional and metabolic disorders. Downregulation of fatty acid translocase (FAT)/Cd36, glutamine synthetase, and pyruvate dehydrogenase kinase isoenzyme 4 is believed to promote lower uptake of fatty acids, lower ammonia incorporation, and higher uptake of glucose, and thus to provide an energy source without using BCAA. Ultimately, the catabolism of BCAA and skeletal muscle protein would be slowed, maintaining BCAA concentrations in blood.

CONCLUSION

We established, for the first time, the regulatory gene pathways of processes involved in hepatic fibrosis and energy metabolism (hypoalbuminemia, hyperammonemia, and carbohydrate catabolism, and their relationships) under BCAA supplementation.

Nutrition support and infections associated with hepatic resection and liver transplantation in patients with chronic liver disease

Malnutrition is common in liver cirrhotic patients who will undergo liver resection or liver transplantation. A precise evaluation of their nutrition status is thus difficult because of the presence of ascites and the edema caused by their impaired protein synthesis. Both perioperative enteral and parenteral nutrition have benefits in reducing the morbidity and mortality of liver surgery, and in general, oral nutrition supplements are recommended. Branched-chain amino acids (BCAAs) promote protein and glycogen synthesis and regulate immune system function. Synbiotics, a combination of pro- and prebiotics, is reported to enhance immune responses. Oral nutrition support with BCAAs, synbiotics, and an immune-enhancing diet have a beneficial effect on preventing the perioperative infections associated with hepatic resection or liver transplantation.

Guidelines on nutritional management in Japanese patients with liver cirrhosis from the perspective of preventing hepatocellular carcinoma

AIM

  The Japanese Nutritional Study Group for Liver Cirrhosis (JNUS) was assembled in 2008 with the support of a Health Labor Sciences Research Grant from the Ministry of Health, Labor and Welfare of Japan. The goal of the study group was to propose new nutritional guidelines for Japanese patients with liver cirrhosis (LC), with the aim of preventing hepatocellular carcinoma.

METHODS

  Between 2008 and 2010, the member investigators of JNUS conducted various clinical and experimental studies on nutrition on LC. These included anthropometric studies, a questionnaire study on daily nutrient intake, clinical trials, experimental studies using animal models, re-evaluation of previous publications and patient education. Over this 3-year period, the group members regularly discussed the nutritional issues related to LC, and a proposal was finally produced.

RESULTS

  Based on the results of JNUS projects and discussions among the members, general recommendations were made on how Japanese patients with LC should be managed nutritionally. These recommendations were proposed with a specific regard to the prevention of hepatocarcinogenesis.

CONCLUSION

  The new JNUS guidelines on nutritional management for Japanese patients with LC will be useful for the actual nutritional management of patients with LC. The JNUS members hope that these guidelines will form the basis for future discussions and provide some direction in nutritional studies in the field of hepatology.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): liver failure and transplantation]

Patients with liver failure have a high prevalence of malnutrition, which is related to metabolic abnormalities due to the liver disease, reduced nutrient intake and alterations in digestive function, among other factors. In general, in patients with liver failure, metabolic and nutritional support should aim to provide adequate nutrient intake and, at the same time, to contribute to patients' recovery through control or reversal of metabolic alterations. In critically-ill patients with liver failure, current knowledge indicates that the organ failure is not the main factor to be considered when choosing the nutritional regimen. As in other critically-ill patients, the enteral route should be used whenever possible. The composition of the nutritional formula should be adapted to the patient's metabolic stress. Despite the physiopathological basis classically described by some authors who consider amino acid imbalance to be a triggering factor and key element in maintaining encephalopathy, there are insufficient data to recommend "specific" solutions (branched-chain amino acid-enriched with low aromatic amino acids) as part of nutritional support in patients with acute liver failure. In patients undergoing liver transplantation, nutrient intake should be started early in the postoperative period through transpyloric access. Prevention of the hepatic alterations associated with nutritional support should also be considered in distinct clinical scenarios.

Nutritional support for liver disease

BACKGROUND

Weight loss and muscle wasting are commonly found in patients with end-stage liver disease. Since there is an association between malnutrition and poor clinical outcome, such patients (or those at risk of becoming malnourished) are often given parenteral nutrition, enteral nutrition, or oral nutritional supplements. These interventions have costs and adverse effects, so it is important to prove that their use results in improved morbidity or mortality, or both.

OBJECTIVES

To assess the beneficial and harmful effects of parenteral nutrition, enteral nutrition, and oral nutritional supplements on the mortality and morbidity of patients with underlying liver disease.

SEARCH METHODS

The following computerised databases were searched: the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, and Science Citation Index Expanded (January 2012). In addition, reference lists of identified trials and review articles and Clinicaltrials.gov were searched. Trials identified in a previous systematic handsearch of Index Medicus were also considered. Handsearches of a number of medical journals, including abstracts from annual meetings, were done. Experts in the field and manufacturers of nutrient formulations were contacted for potential references.

SELECTION CRITERIA

Randomised clinical trials (parallel or cross-over design) comparing groups of patients with any underlying liver disease who received, or did not receive, enteral or parenteral nutrition or oral nutritional supplements were identified without restriction on date, language, or publication status. Six categories of trials were separately considered: medical or surgical patients receiving parenteral nutrition, enteral nutrition, or supplements.

DATA COLLECTION AND ANALYSIS

The following data were sought in each report: date of publication; geographical location; inclusion and exclusion criteria; the type of nutritional support and constitution of the nutrient formulation; duration of treatment; any nutrition provided to the controls; other interventions provided to the patients; number, sex, age of the study participants; hospital or outpatient status; underlying liver disease; risks of bias (sequence generation, allocation concealment, blinding, incomplete outcome reporting, intention-to-treat analysis, selective outcome reporting, others (vested interests, baseline imbalance, early stopping)); mortality; hepatic morbidity (development or resolution of ascites or hepatic encephalopathy, occurrence of gastrointestinal bleeding); quality of life scores; adverse events; infections; lengths of stay in the hospital or intensive care unit; costs; serum bilirubin; postoperative complications (surgical trials only); and nutritional outcomes (nitrogen balance, anthropometric measurements, body weight). The primary outcomes of this review were mortality, hepatic morbidity, quality of life, and adverse events. Data were extracted in duplicate; differences were resolved by consensus.Data for each outcome were combined in a meta-analysis (RevMan 5.1). Estimates were reported using risk ratios or mean differences, along with the 95% confidence intervals (CI). Both fixed-effect and random-effects models were employed; fixed-effect models were reported unless one model, but not the other, found a significant difference (in which case both were reported). Heterogeneity was assessed by the Chi(2) test and I(2) statistic. Subgroup analyses were planned to assess specific liver diseases (alcoholic hepatitis, cirrhosis, hepatocellular carcinoma), acute or chronic liver diseases, and trials employing standard or branched-chain amino acid formulations (for the hepatic encephalopathy outcomes). Sensitivity analyses were planned to compare trials at low and high risk of bias and trials reported as full papers. The following exploratory analyses were undertaken: 1) medical and surgical trials were combined for each nutritional intervention; 2) intention-to-treat analyses in which missing dichotomous data were imputed as best- and worst-case scenarios; 3) all trials were combined to assess mortality; 4) effects were estimated by absolute risk reductions.

MAIN RESULTS

Thirty-seven trials were identified; only one was at low risk of bias. Most of the analyses failed to find any significant differences. The significant findings that were found were the following: 1) icteric medical patients receiving parenteral nutrition had a reduced serum bilirubin (mean difference (MD) -2.86 mg%, 95% CI -3.82 mg% to -1.89 mg%, 3 trials) and better nitrogen balance (MD 3.60 g/day, 95% CI 0.86 g/day to 6.34 g/day, 1 trial); 2) surgical patients receiving parenteral nutrition had a reduced incidence of postoperative ascites only in the fixed-effect model (RR 0.65, 95% CI 0.48 to 0.87, 2 trials, I(2) = 70%) and one trial demonstrated a reduction in postoperative complications, especially infections (pneumonia in particular); 3) enteral nutrition may have improved nitrogen balance in medical patients (although a combination of the three trials was not possible); 4) one surgical trial of enteral nutrition found a reduction in postoperative complications; and 5) oral nutritional supplements had several effects in medical patients (reduced occurrence of ascites (RR 0.57, 95% CI 0.37 to 0.88, 3 trials), possibly (significant differences only seen in the fixed-effect model) reduced rates of infection (RR 0.49, 95% CI 0.24 to 0.99, 3 trials, I(2) = 14%), and improved resolution of hepatic encephalopathy (RR 3.75, 95% CI 1.15 to 12.18, 2 trials, I(2) = 79%). While there was no overall effect of the supplements on mortality in medical patients, the one low risk of bias trial found an increased risk of death in the recipients of the supplements. Three trials of supplements in surgical patients failed to show any significant differences. No new information was derived from the various subgroup or sensitivity analyses. The exploratory analyses were also unrevealing except for a logical conundrum. There was no difference in mortality when all of the trials were combined, but the trials of parenteral nutrition found that those recipients had better survival (RR 0.53, 95% CI 0.29 to 0.98, 10 trials). Either the former observation represents a type II error or the latter one a type I error.

AUTHORS' CONCLUSIONS

The data do not compellingly justify the routine use of parenteral nutrition, enteral nutrition, or oral nutritional supplements in patients with liver disease. The fact that all but one of these trials were at high risks of bias even casts doubt on the few benefits that were demonstrated. Data from well-designed and executed randomised trials that include an untreated control group are needed before any such recommendation can be made. Future trials have to be powered adequately to see small, but clinically important, differences.

Nutritional support for liver disease

BACKGROUND

Weight loss and muscle wasting are commonly found in patients with end-stage liver disease. Since there is an association between malnutrition and poor clinical outcome, such patients (or those at risk of becoming malnourished) are often given parenteral nutrition, enteral nutrition, or oral nutritional supplements. These interventions have costs and adverse effects, so it is important to prove that their use results in improved morbidity or mortality, or both.

OBJECTIVES

To assess the beneficial and harmful effects of parenteral nutrition, enteral nutrition, and oral nutritional supplements on the mortality and morbidity of patients with underlying liver disease.

SEARCH METHODS

The following computerised databases were searched: the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, and Science Citation Index Expanded (January 2012). In addition, reference lists of identified trials and review articles and Clinicaltrials.gov were searched. Trials identified in a previous systematic handsearch of Index Medicus were also considered. Handsearches of a number of medical journals, including abstracts from annual meetings, were done. Experts in the field and manufacturers of nutrient formulations were contacted for potential references.

SELECTION CRITERIA

Randomised clinical trials (parallel or cross-over design) comparing groups of patients with any underlying liver disease who received, or did not receive, enteral or parenteral nutrition or oral nutritional supplements were identified without restriction on date, language, or publication status. Six categories of trials were separately considered: medical or surgical patients receiving parenteral nutrition, enteral nutrition, or supplements.

DATA COLLECTION AND ANALYSIS

The following data were sought in each report: date of publication; geographical location; inclusion and exclusion criteria; the type of nutritional support and constitution of the nutrient formulation; duration of treatment; any nutrition provided to the controls; other interventions provided to the patients; number, sex, age of the study participants; hospital or outpatient status; underlying liver disease; risks of bias (sequence generation, allocation concealment, blinding, incomplete outcome reporting, intention-to-treat analysis, selective outcome reporting, others (vested interests, baseline imbalance, early stopping)); mortality; hepatic morbidity (development or resolution of ascites or hepatic encephalopathy, occurrence of gastrointestinal bleeding); quality of life scores; adverse events; infections; lengths of stay in the hospital or intensive care unit; costs; serum bilirubin; postoperative complications (surgical trials only); and nutritional outcomes (nitrogen balance, anthropometric measurements, body weight). The primary outcomes of this review were mortality, hepatic morbidity, quality of life, and adverse events. Data were extracted in duplicate; differences were resolved by consensus.Data for each outcome were combined in a meta-analysis (RevMan 5.1). Estimates were reported using risk ratios or mean differences, along with the 95% confidence intervals (CI). Both fixed-effect and random-effects models were employed; fixed-effect models were reported unless one model, but not the other, found a significant difference (in which case both were reported). Heterogeneity was assessed by the Chi(2) test and I(2) statistic. Subgroup analyses were planned to assess specific liver diseases (alcoholic hepatitis, cirrhosis, hepatocellular carcinoma), acute or chronic liver diseases, and trials employing standard or branched-chain amino acid formulations (for the hepatic encephalopathy outcomes). Sensitivity analyses were planned to compare trials at low and high risk of bias and trials reported as full papers. The following exploratory analyses were undertaken: 1) medical and surgical trials were combined for each nutritional intervention; 2) intention-to-treat analyses in which missing dichotomous data were imputed as best- and worst-case scenarios; 3) all trials were combined to assess mortality; 4) effects were estimated by absolute risk reductions.

MAIN RESULTS

Thirty-seven trials were identified; only one was at low risk of bias. Most of the analyses failed to find any significant differences. The significant findings that were found were the following: 1) icteric medical patients receiving parenteral nutrition had a reduced serum bilirubin (mean difference (MD) -2.86 mg%, 95% CI -3.82 mg% to -1.89 mg%, 3 trials) and better nitrogen balance (MD 3.60 g/day, 95% CI 0.86 g/day to 6.34 g/day, 1 trial); 2) surgical patients receiving parenteral nutrition had a reduced incidence of postoperative ascites only in the fixed-effect model (RR 0.65, 95% CI 0.48 to 0.87, 2 trials, I(2) = 70%) and one trial demonstrated a reduction in postoperative complications, especially infections (pneumonia in particular); 3) enteral nutrition may have improved nitrogen balance in medical patients (although a combination of the three trials was not possible); 4) one surgical trial of enteral nutrition found a reduction in postoperative complications; and 5) oral nutritional supplements had several effects in medical patients (reduced occurrence of ascites (RR 0.57, 95% CI 0.37 to 0.88, 3 trials), possibly (significant differences only seen in the fixed-effect model) reduced rates of infection (RR 0.49, 95% CI 0.24 to 0.99, 3 trials, I(2) = 14%), and improved resolution of hepatic encephalopathy (RR 3.75, 95% CI 1.15 to 12.18, 2 trials, I(2) = 79%). While there was no overall effect of the supplements on mortality in medical patients, the one low risk of bias trial found an increased risk of death in the recipients of the supplements. Three trials of supplements in surgical patients failed to show any significant differences. No new information was derived from the various subgroup or sensitivity analyses. The exploratory analyses were also unrevealing except for a logical conundrum. There was no difference in mortality when all of the trials were combined, but the trials of parenteral nutrition found that those recipients had better survival (RR 0.53, 95% CI 0.29 to 0.98, 10 trials). Either the former observation represents a type II error or the latter one a type I error.

AUTHORS' CONCLUSIONS

The data do not compellingly justify the routine use of parenteral nutrition, enteral nutrition, or oral nutritional supplements in patients with liver disease. The fact that all but one of these trials were at high risks of bias even casts doubt on the few benefits that were demonstrated. Data from well-designed and executed randomised trials that include an untreated control group are needed before any such recommendation can be made. Future trials have to be powered adequately to see small, but clinically important, differences.

Beneficial effects of supplementation with branched-chain amino acids on postoperative bacteremia in living donor liver transplant recipients

The aim of this study was to investigate the effects of preoperative oral supplementation with branched-chain amino acids (BCAAs) on postoperative bacteremia after living donor liver transplantation (LDLT) for chronic liver failure. Two hundred thirty-six patients who underwent adult-to-adult LDLT were evaluated in this retrospective study. The patients were divided into 2 groups: those who received oral supplementation with BCAAs before transplantation (the BCAA group; n = 129) and those who did not (the non-BCAA group; n = 107). Before the LDLT indication was determined, BCAA supplementation was prescribed by a hepatologist to preserve hepatic reserves. The clinical characteristics and the incidence of bacteremia were compared between the 2 groups. As for clinical characteristics, the Child-Pugh scores (P = 0.0003) and the Model for End-Stage Liver Disease scores (P = 0.0008) were significantly higher in the BCAA group versus the non-BCAA group. The incidence of bacteremia for Child-Pugh class C patients was significantly lower in the BCAA group (6/90 or 6.7%) versus the non-BCAA group (11/50 or 22.0%, P = 0.0132). In a multivariate analysis, non-BCAA supplementation was an independent risk factor for bacteremia. In conclusion, preoperative BCAA supplementation might reduce the incidence of bacteremia after LDLT. Nevertheless, this is a preliminary report, and further studies, such as randomized, prospective studies, are necessary to clarify the beneficial effects of BCAA supplementation on postoperative bacteremia after liver transplantation.

Branched-chain amino acids in liver disease: new aspects of long known phenomena

PURPOSE OF REVIEW

To provide an overview of findings on the role of branched-chain amino acids (BCAAs) in the pathophysiology, pathobiochemistry, and treatment of liver cirrhosis and its complications that have been published since or were not included in the last review on this topic in 2007 in this journal.

RECENT FINDINGS

There has been continued interest in the potential of oral BCAA supplements in improving energy metabolism, nitrogen metabolism, carbohydrate metabolism, insulin resistance, severity of liver disease, serum albumin levels, quality of serum albumin, or postoperative complication rates. Unfortunately, many trials suffer from lacking or inadequate controls or small sample size. In a fine example of scientific perseverance, Dutch researchers uncovered the long-known phenomenon of ingested blood being highly comagenic in patients with cirrhosis to be due to the low biologic value of blood protein. The absence of isoleucine and the abundance of leucine in the hemoglobin molecule by way of BCAA antagonism leads to impaired protein synthesis and azotemia paving the way for hepatic encephalopathy.

SUMMARY

Recognizing hypoisoleucinemia and BCAA antagonism following gastrointestinal bleeding, and its successful treatment by isoleucine infusion has advanced our understanding of the role of BCAA in liver cirrhosis.

The impact of nutrition on cirrhotic patients awaiting liver transplantation

PURPOSE OF REVIEW

To review the most recent aspects of nutrition therapy of cirrhotic patients on the waiting list for liver transplantation.

RECENT FINDINGS

Undernutrition has been widely reported among these patients, despite the lack of consensus on the best nutritional assessment tools in this population. Nutrition therapy has been marked by controversy. Nonetheless, recent findings have pointed out to the important role of the nutrition status and of some specific nutrients on the outcome of these patients.

SUMMARY

We report the latest findings on nutrition care of patients with end-stage liver disease on the waiting list for liver transplantation such as the impact of the nutritional status on outcome, probiotic and branched-chain amino acid supplementation, as well as the use of immunomodulating formula. Another important strategy that has been shown to improve these patients' nutritional care is the offering of nocturnal meals and micronutrient supplementation.