Consilience in sarcopenia of cirrhosis

Changes in skeletal muscle mass after endoscopic treatment in patients with esophageal varices

To the best of our knowledge, no available data with regard to changes in skeletal muscle mass for liver cirrhosis (LC) patients with esophageal varices (EVs) undergoing endoscopic therapy as a primary prophylaxis could exist. As endoscopic therapies, such as endoscopic injection sclerotherapy or endoscopic band ligation for EVs, accompany invasive procedure and patients with EVs receiving endoscopic therapies mostly rest in bed during hospitalization, clarifying these issues are clinically of importance. The purposes of this study were therefore to examine changes in skeletal muscle mass for LC patients with EVs undergoing endoscopic therapy as a primary prophylaxis and to identify pretreatment predictors which are associated with the amelioration in skeletal muscle mass. This is a subgroup analysis in our previous randomized controlled trial. A total of 51 LC patients with EVs were analyzed. Skeletal muscle mass was assessed using bioimpedance analysis (BIA). Skeletal muscle index (SMI) was defined as sum of skeletal muscle mass in body trunk and upper and lower extremities divided by height squared (cm/m) using data for BIA. We compared the changes in SMI at baseline and SMI at Day 50 after endoscopic treatment for EVs. Our study cohort included 33 males and 18 females with median (range) age of 62 (29-81) years. There were 31 patients with Child-Pugh A and 20 with Child-Pugh B. The median SMI for the entire cohort at baseline was 8.96 cm/m (range, 5.87-13.11 cm/m), while the median SMI for the entire cohort at Day 50 was 8.83 cm/m (range, 5.59-12.29 cm/m) (P = .9995). In baseline characteristics, prealbumin (P = .0477), branched-chain amino acid to tyrosine ratio (BTR) (P = .0056), and retinol-binding protein (P = .0296) in the increased SMI group (n = 15) were significantly higher than those in the nonincreased SMI group (n = 36). Multivariate analysis for the above 3 significant factors showed that only BTR was a significant prognostic pretreatment factor linked to the presence of increased SMI (P = .0235). In conclusion, pretreatment BTR level can be helpful for predicting increased SMI after endoscopic therapy as a primary prophylaxis for LC patients with EVs.

A Comparison of Muscle Function, Mass, and Quality in Liver Transplant Candidates: Results From the Functional Assessment in Liver Transplantation Study

BACKGROUND

Sarcopenia and functional impairment are common and lethal extrahepatic manifestations of cirrhosis. We aimed to determine the association between computed tomography (CT)-based measures of muscle mass and quality (sarcopenia) and performance-based measures of muscle function.

METHODS

Adults listed for liver transplant underwent testing of muscle function (grip strength, Short Physical Performance Battery [SPPB]) within 3 months of abdominal CT. Muscle mass (cm/m) = total cross-sectional area of psoas, paraspinal, and abdominal wall muscles at L3 on CT, normalized for height. Muscle quality = mean Hounsfield units for total skeletal muscle area at L3.

RESULTS

Among 292 candidates, median grip strength was 31 kg, SPPB score was 11, muscle mass was 49 cm/m, and muscle quality was 35 Hounsfield units. Grip strength weakly correlated with muscle mass (ρ = 0.26, P < 0.001) and quality (ρ = 0.27, P < 0.001) in men, and muscle quality (ρ = 0.23, P = 0.02), but not muscle mass, in women. Short Physical Performance Battery correlated weakly with muscle quality in men (ρ = 0.38, P < 0.001) and women (ρ = 0.25, P = 0.02), however, did not correlate with muscle mass in men or women. After adjustment for sex, model for end-stage liver disease (MELD)-Na, hepatocellular carcinoma, and body mass index, grip strength (hazard ratio [HR], 0.74; 95% confidence interval [95% CI], 0.59-0.92; P = 0.008), SPPB (HR, 0.89; 95% CI, 0.82-0.97; P = 0.01), and muscle quality (HR, 0.77; 95% CI, 0.63-0.95; P = 0.02) were associated with waitlist mortality, but muscle mass was not (HR, 0.91; 95% CI, 0.75-1.11; P = 0.35).

CONCLUSIONS

Performance-based tests of muscle function are only modestly associated with CT-based muscle measures. Given that they predict waitlist mortality and can be conducted quickly and economically, tests of muscle function may have greater clinical utility than CT-based measures of sarcopenia.

Ammonia toxicity: from head to toe?

Ammonia is diffused and transported across all plasma membranes. This entails that hyperammonemia leads to an increase in ammonia in all organs and tissues. It is known that the toxic ramifications of ammonia primarily touch the brain and cause neurological impairment. However, the deleterious effects of ammonia are not specific to the brain, as the direct effect of increased ammonia (change in pH, membrane potential, metabolism) can occur in any type of cell. Therefore, in the setting of chronic liver disease where multi-organ dysfunction is common, the role of ammonia, only as neurotoxin, is challenged. This review provides insights and evidence that increased ammonia can disturb many organ and cell types and hence lead to dysfunction.

Falls in Patients With Liver Cirrhosis

Health-related quality of life (HRQOL) has become an important outcome for patients with liver cirrhosis as the number of transplantation candidates increases by the progression of treatment strategies. Falls and fall-related injuries are common in patients with liver cirrhosis and negatively affect HRQOL. Many factors increase the risk for falls such as minimal hepatic encephalopathy, psychoactive drugs, muscle strength, autonomic dysfunction, hyponatremia, and sleep problems. It is important to understand the underlying mechanisms for falls in cirrhotic patients to prevent severe injuries such as fractures, decrease healthcare costs, and improve HRQOL. Healthcare professionals, including physiotherapists and nurses, should be aware of the higher risk for falls in this population and therapeutic interventions must be designed for patients, especially those waiting on the transplant list.

Sarcopenia predicts reduced survival in patients with hepatocellular carcinoma at first diagnosis

 Background. Sarcopenia is a complication and independent risk factor for mortality in patients with liver cirrhosis.

AIM

To assess the prevalence and influence of sarcopenia on overall survival in a cohort of cirrhotic patients with hepatocellular carcinoma managed in a tertiary center.

MATERIAL AND METHODS

Abdominal computed tomography of 92 consecutive hepatocellular carcinoma cirrhotic patients, enrolled and followed from 2004 to 2014, were retrospectively studied with a software analyzing the cross-sectional areas of muscles at third lumbar vertebra level. Data was normalized for height, skeletal muscle index (SMI) calculated and presence of Sarcopenia measured. Sarcopenia was defined by SMI ≤ 41 cm2/m2 for women and ≤ 53 cm2/m2 for men with body mass index (BMI) ≥ 25, and ≤ 43 cm2/m2 for men and women with BMI < 25, respectively.

RESULTS

Median age at diagnosis was 71.9 years (30.7-86.4) and BMI 24.7 (17.5-36.7), comparable in women 23.1, (17.5-36.7) and men 24.7 (18.4-36.7). A class of CHILD score and BCLC A prevailed (55.4% and 41.3%, respectively); metastatic disease was found in 12% of cases. Sarcopenia was present in 40.2% of cases, mostly in females (62.9%; p = 0.005). Mean overall survival was reduced in sarcopenic patients, 66 (95% CI 47 to 84) vs. 123 (95% CI 98 to 150) weeks (p = 0.001). At multivariate analysis, sarcopenia was a predictor of reduced overall survival, independent of age (p = 0.0027).

CONCLUSIONS

This retrospective study shows high prevalence of sarcopenia among cirrhotic patients with hepatocellular carcinoma. Presence of sarcopenia was identified as independent predictor of reduced overall survival. As easily measurable by CT, sarcopenia should be determined for prognostic purposes in this patient population.

Compensating effect of minor portal hypertension on the muscle mass loss-related poor prognosis in cirrhosis

Background: To examine the influence of the severity of portal hemodynamic abnormality on the prognosis of cirrhosis with respect to the muscle mass loss (MML). Methods: The study involved a subgroup analysis in 98 cirrhosis patients (63.5 ± 11.8 years) who prospectively underwent both Doppler ultrasound and hepatic venous catheterization. The prognostic influence of MML diagnosed by computed tomography using the L3 skeletal muscle index was evaluated (median observation period, 32.7 months). Results: The cumulative survival rate showed difference between patients with MML (n = 34; 82.2%/1year, 41.2%/3years and 36.1%/5years) and those without (n = 64; 92.1%/1year, 74.9%/3years and 69.4%/5years; P = 0.005). When divided with respect to the portal velocity, the survival rate showed differences between patients with and without MML in the cohort < 12.8 cm/s (n=52, p=0.009) and ≥ 12.8 cm/s (n=44, p=0.041). The survival rate also showed differences between patients with MML (n = 24; 78.8%/1year, 40.6%/3years and 34.8%/5years) and those without (n = 45; 91.1%/1year, 71.3%/3years and 63.1%/5years; P = 0.008) in the cohort with hepatic venous pressure gradient (HVPG) > 12 mmHg. However, in the cohort with HVPG ≤ 12 mmHg, survival rate showed no difference between patients with MML (n=10; 100%/1year, 61.9%/3years and 61.9%/5years) and those without (n=19; 93.8%/1year, 71.2%/3years and 59.4%/5years; p = 0.493) Conclusion: Lower HVPG has a compensating effect on the MML-induced poor prognosis of cirrhosis. Care should be taken in the evaluation of the influence of MML in consideration of the severity of portal hypertension.

Frailty as Tested by Gait Speed is an Independent Risk Factor for Cirrhosis Complications that Require Hospitalization

OBJECTIVES

Frailty is a known risk factor for major life-threatening liver transplant complications, deaths, and waitlist attrition. Whether frailty indicates risk for adverse outcomes in cirrhosis short of lethality is not well defined. We hypothesized that clinical measurements of frailty using gait speed and grip strength would indicate the risk of subsequent hospitalization for the complications of cirrhosis.

METHODS

We assessed frailty as gait speed and grip strength in a 1-year prospective study of 373 cirrhotic patients evaluated for or awaiting liver transplantation. We determined its association with the outcome of subsequent hospital days/100 days at risk for 7 major complications of cirrhosis. We tested potential covariate influences of Model for Endstage Liver Disease (MELD) and Child-Turcotte-Pugh (CTP) scores, age, sex, height, depression, narcotic use, vitamin D deficiency, and hepatocellular carcinoma using multivariable modeling.

RESULTS

Patients experienced 2.14 hospital days/100 days at risk, or 7.81 days/year. Frailty measured by gait speed was a strong risk factor for hospitalization for all cirrhosis complications. Each 0.1 m/s gait speed decrease was associated with 22% greater hospital days (P<0.001). Grip strength showed a similar but nonsignificant association. Gait speed remained independently significant when adjusted for MELD, CTP, and other covariates. At hospital costs of $4,000/day, patients with normal 1 m/s gait speed spent 6.2 days and $24,800/year; patients with 0.5 m/s speed spent 21.2 days and $84,800/year; and patients with 0.25 m/s speed spent 40.2 days and $160,800/year.

CONCLUSIONS

Frailty as measured by gait speed is an independent and potentially modifiable risk factor for cirrhosis complications requiring hospitalization. The potential clinical value of frailty measurements to help define such risk merits broader evaluation.

Sarcopenia from mechanism to diagnosis and treatment in liver disease

Sarcopenia or loss of skeletal muscle mass is the major component of malnutrition and is a frequent complication in cirrhosis that adversely affects clinical outcomes. These include survival, quality of life, development of other complications and post liver transplantation survival. Radiological image analysis is currently utilized to diagnose sarcopenia in cirrhosis. Nutrient supplementation and physical activity are used to counter sarcopenia but have not been consistently effective because the underlying molecular and metabolic abnormalities persist or are not influenced by these treatments. Even though alterations in food intake, hypermetabolism, alterations in amino acid profiles, endotoxemia, accelerated starvation and decreased mobility may all contribute to sarcopenia in cirrhosis, hyperammonemia has recently gained attention as a possible mediator of the liver-muscle axis. Increased muscle ammonia causes: cataplerosis of α-ketoglutarate, increased transport of leucine in exchange for glutamine, impaired signaling by leucine, increased expression of myostatin (a transforming growth factor beta superfamily member) and an increased phosphorylation of eukaryotic initiation factor 2α. In addition, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy mediated proteolysis, also play a role. These molecular and metabolic alterations may contribute to the anabolic resistance and inadequate response to nutrient supplementation in cirrhosis. Central and skeletal muscle fatigue contributes to impaired exercise capacity and responses. Use of proteins with low ammoniagenic potential, leucine enriched amino acid supplementation, long-term ammonia lowering strategies and a combination of resistance and endurance exercise to increase muscle mass and function may target the molecular abnormalities in the muscle. Strategies targeting endotoxemia and the gut microbiome need further evaluation.

Metabolic adaptation of skeletal muscle to hyperammonemia drives the beneficial effects of l-leucine in cirrhosis

BACKGROUND & AIMS

Increased skeletal muscle ammonia uptake with loss of muscle mass adversely affects clinical outcomes in cirrhosis. Hyperammonemia causes reduced protein synthesis and sarcopenia but the cellular responses to impaired proteostasis and molecular mechanism of l-leucine induced adaptation to ammonia induced stress were determined.

METHODS

Response to activation of amino acid deficiency sensor, GCN2, in the skeletal muscle from cirrhotic patients and the portacaval anastomosis (PCA) rat were quantified. During hyperammonemia and l-leucine supplementation, protein synthesis, phosphorylation of eIF2α, mTORC1 signaling, l-leucine transport and response to l-leucine supplementation were quantified. Adaptation to cellular stress via ATF4 and its target GADD34 were also determined.

RESULTS

Activation of the eIF2α kinase GCN2 and impaired mTORC1 signaling were observed in skeletal muscle from cirrhotic patients and PCA rats. Ammonia activated GCN2 mediated eIF2α phosphorylation (eIF2α-P) and impaired mTORC1 signaling that inhibit protein synthesis in myotubes and MEFs. Adaptation to ammonia induced stress did not involve translational reprogramming by activation transcription factor 4 (ATF4) dependent induction of the eIF2α-P phosphatase subunit GADD34. Instead, ammonia increased expression of the leucine/glutamine exchanger SLC7A5, l-leucine uptake and intracellular l-leucine levels, the latter not being sufficient to rescue the inhibition of protein synthesis, due to potentially enhanced mitochondrial sequestration of l-leucine. l-leucine supplementation rescued protein synthesis inhibition caused by hyperammonemia.

CONCLUSIONS

Response to hyperammonemia is reminiscent of the cellular response to amino acid starvation, but lacks the adaptive ATF4 dependent integrated stress response (ISR). Instead, hyperammonemia-induced l-leucine uptake was an adaptive response to the GCN2-mediated decreased protein synthesis.

LAY SUMMARY

Sarcopenia or skeletal muscle loss is the most frequent complication in cirrhosis but there are no treatments because the cause(s) of muscle loss in liver disease are not known. Results from laboratory experiments in animals and muscle cells were validated in human patients with cirrhosis to show that ammonia plays a key role in causing muscle loss in patients with cirrhosis. We identified a novel stress response to ammonia in the muscle that decreases muscle protein content that can be reversed by supplementation with the amino acid l-leucine.

Proposal for new diagnostic criteria for low skeletal muscle mass based on computed tomography imaging in Asian adults

OBJECTIVES

Low skeletal muscle, referred to as sarcopenia, has been shown to be an independent predictor of lower overall survival in various kinds of diseases. Several studies have evaluated the low skeletal muscle mass using computed tomography (CT) imaging. However, the cutoff values based on CT imaging remain undetermined in Asian populations.

METHODS

Preoperative plain CT imaging at the third lumbar vertebrae level was used to measure the psoas muscle mass index (PMI, cm(2)/m(2)) in 541 adult donors for living donor liver transplantation (LDLT). We analyzed PMI distribution according to sex or donor age, and determined the sex-specific cutoff values of PMI to define low skeletal muscle mass.

RESULTS

PMI in men was significantly higher than observed in women (8.85 ± 1.61 cm(2)/m(2) versus 5.77 ± 1.21 cm(2)/m(2); P < 0.001). PMI was significantly lower in individuals ≥50 y than in younger donors in both men and women (P < 0.001 and P < 0.001, respectively). On the basis of the younger donor data, we determined the sex-specific cutoff values for the low skeletal muscle mass were 6.36 cm(2)/m(2) for men and 3.92 cm(2)/m(2) for women (mean - 2 SD).

CONCLUSION

Data from healthy young Asian adults were used to establish new criteria for low skeletal muscle mass that would be applicable for defining sarcopenia in Asian populations.

Testosterone therapy increases muscle mass in men with cirrhosis and low testosterone: A randomised controlled trial

BACKGROUND & AIMS

Low testosterone and sarcopenia are common in men with cirrhosis and both are associated with increased mortality. Whether testosterone therapy in cirrhosis improves muscle mass and other outcomes is unknown.

METHODS

We conducted a 12-month, double-blinded, placebo-controlled trial of intramuscular testosterone undecanoate in 101 men with established cirrhosis and low serum testosterone (total testosterone <12nmol/L or free testosterone <230pmol/L) in a single tertiary centre. Body composition was assessed using dual-energy X-ray absorptiometry at baseline, 6 and 12months.

RESULTS

At study completion, appendicular lean mass was significant higher in testosterone-treated subjects, with a mean adjusted difference (MAD) of +1.69kg, (CI +0.40; +2.97kg, p=0.021). Secondary outcomes included a substantially higher total lean mass in the active group (MAD +4.74kg, CI +1.75; +7.74kg, p=0.008), matched by reduced fat mass (MAD -4.34kg, CI -6.65; -2.04, p<0.001). Total bone mass increased (MAD +0.08kg, CI +0.01; +0.15kg, p=0.009) as did bone mineral density at the femoral neck (MAD +0.287points, CI +0.140; +0.434, p<0.001). Haemoglobin was higher with testosterone therapy (MAD +10.2g/L, CI +1.50; +18.9g/L, p=0.041) and percentage glycosylated haemoglobin (HbA1c) lower (MAD -0.35%, CI -0.05; -0.54, p=0.028). Mortality was non-significantly lower in testosterone-treated patients (16% vs. 25.5%, p=0.352). There was no increase in adverse events in testosterone-treated subjects.

CONCLUSION

Testosterone therapy in men with cirrhosis and low serum testosterone safely increases muscle mass, bone mass and haemoglobin, and reduces fat mass and HbA1c. This is the first evidence-based therapy for sarcopenia in cirrhosis and thus requires larger-scale investigation into its potential impact on mortality.

LAY SUMMARY

Both low testosterone and muscle wasting are associated with increased risk of death in men with severe liver disease. Administering testosterone to men with liver disease who have low testosterone levels significantly increases their muscle mass. In addition, testosterone has non-muscle beneficial effects which may be able to increase survival in this population.

CLINICAL TRIAL NUMBER

Australian New Zealand Clinical Trials Registry trial number ACTRN 12614000526673.

Nutritional evaluation in cirrhosis: Emphasis on the phase angle

Protein-calorie malnutrition (PCM) is a common condition in cirrhotic patients, leading to a worse prognosis, complications, poor quality of life and lower survival rates. Among ways of assessing nutritional status, there are anthropometric methods such as the evaluation of the triceps skinfold, the arm circumference, the arm muscle circumference and the body mass index, and non-anthropometric methods such as the subjective global assessment, the handgrip strength of non-dominant hand, and the bioelectrical impedance analysis (BIA). PCM is frequently under-diagnosed in clinical settings in patients with cirrhosis due to the limitations of nutritional evaluation methods in this population. BIA is a useful method, but cannot be indicated in patients with abnormal body composition. In these situations, the phase angle (PA) has been used, and can become an important tool in assessing nutritional status in any situation. The PA is superior to anthropometric methods and might be considered as a nutritional indicator in cirrhosis. The early characterization of the nutritional status in patients with cirrhosis means an early nutritional intervention, with a positive impact on patients' overall prognosis. Among the usually accepted methods for nutritional diagnosis, the PA provides information in a quick and objective manner.

Japan Society of Hepatology guidelines for sarcopenia in liver disease (1st edition): Recommendation from the working group for creation of sarcopenia assessment criteria

Sarcopenia is defined by muscle loss and muscle dysfunction. Sarcopenia is classified into primary and secondary types, based on the cause. Primary sarcopenia is mainly aging-related sarcopenia, whereas secondary sarcopenia is the reduced muscle mass and strength that accompanies an underlying disease. Given the essential role of the liver in metabolism, secondary sarcopenia due to nutritional disorders or other factors can frequently occur in liver disease. In 2015, the Japan Society of Hepatology (JSH) decided to establish its own assessment criteria for sarcopenia in liver disease because the number of liver disease patients with sarcopenia is expected to increase and there is cumulative evidence to indicate sarcopenic patients have poor clinical outcomes. A working group to create assessment criteria for sarcopenia has thus been established by the JSH. In this article, we summarize the current knowledge with regard to sarcopenia and present the assessment criteria for sarcopenia in liver disease proposed by the JSH (1st edition). To the best of our knowledge, this is globally the first proposed assessment criteria for sarcopenia specializing in liver disease.

Nutrition and Alcoholic Liver Disease: Effects of Alcoholism on Nutrition, Effects of Nutrition on Alcoholic Liver Disease, and Nutritional Therapies for Alcoholic Liver Disease

Malnutrition is the most frequent and nearly universal consequence in alcoholic liver disease (ALD) that adversely affects clinical outcomes. Sarcopenia or skeletal muscle loss is the major component of malnutrition in liver disease. There are no effective therapies to prevent or reverse sarcopenia in ALD because the mechanisms are not well understood. Consequences of liver disease including hyperammonemia, hormonal perturbations, endotoxemia and cytokine abnormalities as well as the direct effects of alcohol and its metabolites contribute to sarcopenia in ALD. This article focuses on the prevalence, methods to quantify malnutrition, specifically sarcopenia and potential therapies including novel molecular targeted treatments.

Rapid skeletal muscle wasting predicts worse survival in patients with liver cirrhosis

AIM

Sarcopenia impairs the outcome of patients with liver cirrhosis independently of liver function reserves. The aim of this study was to investigate whether the rate of skeletal muscle wasting predicts mortality in cirrhotic patients.

METHODS

This retrospective study evaluated 149 cirrhotic patients who visited our hospital between March 2004 and September 2012. The skeletal muscle cross-sectional area at the level of the third lumbar vertebra was measured by computed tomography, from which the skeletal muscle index was obtained for diagnosis of sarcopenia. The relative change in skeletal muscle area per year (ΔSMA/y) was calculated in each patient. Cox proportional hazards regression analysis was performed to evaluate risk factors for mortality.

RESULTS

Of the 149 cirrhotic patients, 94 (63%) were diagnosed with sarcopenia. The median of ΔSMA/y in all patients was -2.2%. For patients in Child-Pugh class A, B and C, ΔSMA/y was -1.3%, -3.5% and -6.1%, respectively. During a median follow-up period of 39 months (range, 1-110), 45 patients (30%) died. The optimal cut-off value of ΔSMA/y for predicting mortality was -3.1%; the survival rate in patients with ΔSMA/y of -3.1% or less was significantly lower than in patients with ΔSMA/y of more than -3.1% (P < 0.0001). The multivariate Cox proportional hazards model found ΔSMA/y of -3.1% or less to be significantly associated with mortality in cirrhotic patients (hazard ratio = 2.73, 95% confidence interval = 1.43-5.44, P < 0.01).

CONCLUSION

ΔSMA/y is useful for predicting mortality in patients with liver cirrhosis. Management of skeletal muscle may contribute toward improving the outcome of cirrhotic patients.

Sarcopenic obesity and myosteatosis are associated with higher mortality in patients with cirrhosis

BACKGROUND AND AIMS

Obesity is frequently associated with cirrhosis, and cirrhotic patients may develop simultaneous loss of skeletal muscle and gain of adipose tissue, culminating in the condition of sarcopenic obesity. Additionally, muscle depletion is characterized by both a reduction in muscle size and increased proportion of muscular fat, termed myosteatosis. In this study, we aimed to establish the frequency and clinical significance of sarcopenia, sarcopenic obesity and myosteatosis in cirrhotic patients.

METHODS

We analysed 678 patients with cirrhosis. Sarcopenia, sarcopenic obesity and myosteatosis were analysed by CT scan using the third lumbar vertebrae skeletal muscle and attenuation indexes, using previously validated gender-and body mass index-specific cutoffs.

RESULTS

Patients were predominately men (n = 457, 67%), and cirrhosis aetiology was hepatitis C virus in 269 patients (40%), alcohol in 153 (23%), non-alcoholic steatohepatitis/cryptogenic in 96 (14%), autoimmune liver disease in 55 (8%), hepatitis B virus in 43 (6%), and others in 5 patients (1%). Sarcopenia was present in 292 (43%), 135 had sarcopenic obesity (20%) and 353 had myosteatosis (52%). Patients with sarcopenia (22 ± 3 vs. 95 ± 22 months, P < 0.001), sarcopenic obesity (22 ± 3 vs. 95 ± 22 months, P < 0.001), and myosteatosis (28 ± 5 vs. 95 ± 22 months, P < 0.001) had worse median survival than patients without muscular abnormalities. By multivariate Cox regression analysis, both sarcopenia [hazard ratio (HR) 2.00, 95% confidence interval (CI) 1.44-2.77, P < 0.001], and myosteatosis (HR 1.42, 95% CI 1.02-1.07, P = 0.04) were associated with mortality.

CONCLUSIONS

Sarcopenia, sarcopenic obesity and myosteatosis are often present in patients with cirrhosis, and sarcopenia and myosteatosis are independently associated with a higher long-term mortality in cirrhosis.

Cause and management of muscle wasting in chronic liver disease

PURPOSE OF REVIEW

Sarcopenia or loss of skeletal muscle mass is the major component of malnutrition and occurs in the majority of patients with liver disease. Lower muscle contractile function also contributes to the adverse consequences of sarcopenia. There are no effective therapies to prevent or reverse sarcopenia in liver disease. This review will discuss the advances in diagnosis, pathogenesis, and treatment options for sarcopenia in liver disease.

RECENT FINDINGS

Sarcopenia increases mortality and risk of development of other complications of cirrhosis, and worsens postliver transplant outcomes while quality of life is decreased. Unlike other complications of cirrhosis that reverse after liver transplantation, sarcopenia may not improve and actually worsens. Impaired skeletal muscle protein synthesis and increased proteolysis via autophagy contribute to sarcopenia. Hyperammonemia is the best-studied mediator of the liver-muscle axis. Molecular studies show increased expression of myostatin whereas metabolic studies show impaired mitochondrial function and tricarboxylic acid cycle intermediates because of cataplerosis of α-ketoglutarate. Impaired skeletal muscle pyruvate and fatty acid oxidation during hyperammonemia suggest amino acids are diverted to acetyl CoA and potentially aggravate hyperammonemia. Nutritional supplementation is of limited or no benefit and suggests that cirrhosis is a state of anabolic resistance. Exercise may be beneficial but whether it overcomes anabolic resistance is not known.

SUMMARY

The high clinical significance of sarcopenia is well established. Current approaches to nutritional supplementation have not been effective in reversing sarcopenia because of anabolic resistance. Myostatin antagonists, specific amino acid supplementation, mitochondrial protection, and combination endurance-resistance exercise are potential future therapeutic options.

Review article: sarcopenia in cirrhosis--aetiology, implications and potential therapeutic interventions

BACKGROUND

Sarcopenia (loss of muscle mass) is common in cirrhosis and is associated with poor outcomes. Current teaching recommends the use of protein supplementation and exercise, however, this fails to address many other factors which contribute to muscle loss in this setting.

AIMS

To summarise existing knowledge regarding the aetiology of sarcopenia in cirrhosis, diagnostic modalities and the clinical significance of this condition. In addition to discuss recent research findings that may allow the development of more effective treatments.

METHODS

We conducted a Medline and PubMed search using the search terms 'sarcopenia', 'muscle', 'body composition', 'cirrhosis', 'liver' and 'malnutrition' from inception to October 2015.

RESULTS

Cirrhotic patients with sarcopenia have reduced survival, experience increased rates of infection and have worse outcomes following liver transplantation. The aetiology of this condition is more complex than simple protein and calorie malnutrition. Cirrhosis also results in depleted glycogen stores and metabolic alterations that cause excessive protein catabolism, increased activation of the ubiquitin-proteasome pathway and inappropriate muscle autophagy. Satellite cell differentiation and proliferation is also reduced due to a combination of elevated myostatin levels, reduced IGF-1 and hypogonadism. Although there is some evidence supporting the use of late evening snacks, branched chain amino acid supplementation and high protein/high calorie diets, well designed clinical trials addressing the effects of treatment on body composition in cirrhosis are lacking.

CONCLUSION

Sarcopenia in cirrhosis has a complex pathogenesis and simple dietary interventions are insufficient. Improved understanding of the multiple mechanisms involved should allow the development of more effective therapies, which target the specific underlying metabolic derangements.

Nonalcoholic steatohepatitis is strongly associated with sarcopenic obesity in patients with cirrhosis undergoing liver transplant evaluation

BACKGROUND

Sarcopenia is the most common complication of cirrhosis and adversely affects quality of life and outcomes before, during, and after liver transplantation. We studied predictors of sarcopenia and sarcopenic obesity in patients with cirrhosis undergoing liver transplant (LT) evaluation.

METHODS

A retrospective analysis of 207 adult cirrhotic patients that underwent LT from January 2008 to December 2013 was performed at our institution.

RESULTS

Two hundred seven patients were evaluated, 68% were male with a mean age of 54 ± 8 years. The most common etiology of cirrhosis was alcoholic liver disease (38.6%), followed by chronic hepatitis C (38.2%), nonalcoholic steatohepatitis (NASH) (21.7%), and hepatocellular carcinoma (HCC) (24.6%). The mean body mass index of the cohort was of 30.1 ± 5.7 kg/m(2) . Forty-eight percent of these patients were obese. Of the 207 patients, 88% had computed tomographic (CT) scans within 90 days before transplant; of these, 59% had sarcopenia found during LT evaluation. Of the patients with pretransplant sarcopenia, 59 had CT scan at 6 months posttransplant and 56 (95%) remained sarcopenic. Of the 56 patients who had sarcopenia at 6 months, 31 had available CT scans at 1 year, and 100% persisted with sarcopenia. These 31 subjects had a mean skeletal muscle index of 35 at 6 months and 36 at 1 year. SO was found in 41.7% of our patients. On multivariable regression analysis, obesity and age were found to be independently associated with pretransplant sarcopenia after controlling for gender and alcohol liver disease diagnosis (P = 0.00001, odds ratio [OR] 0.22, and P = 0.008, OR 2.0, respectively). A multivariable logistic regression analysis found that NASH as cause of cirrhosis and model of end-stage liver disease score are independent predictors of sarcopenic obesity after controlling for age, gender, alcoholic liver disease diagnosis, and HCC (P = 0.014 and 0.038, respectively; 95% confidence interval, 1.44-25.26 and 1.00-1.15, respectively; OR 6.03, 1.08, respectively).

CONCLUSIONS

Sarcopenia and sarcopenic obesity is seen in a significant number of patients with cirrhosis undergoing LT evaluation. Sarcopenia progresses after LT initially and does not recover at least within the first year after surgery. Obesity is an independent predictor of pretransplant sarcopenia and NASH was associated with 6-fold increased risk of having sarcopenic obesity in cirrhotic patients in our cohort.

Newly Developed Sarcopenia as a Prognostic Factor for Survival in Patients who Underwent Liver Transplantation

Introduction

The relationship between a perioperative change in sarcopenic status and clinical outcome of liver transplantation (LT) is unknown. We investigated whether post-LT sarcopenia and changes in sarcopenic status were associated with the survival of patients.

Method

This retrospective study was based on a cohort of 145 patients from a single transplant center who during a mean of 1 year after LT underwent computed tomography imaging evaluation. The cross-sectional area of the psoas muscle of LT patients was compared with that of age- and sex-matched healthy individuals. The Cox proportional hazards regression model was used to determine whether post-LT sarcopenia and changes in sarcopenic status affect post-LT survival.

Results

The mean age at LT of the 116 male and 29 female patients was 50.2 ± 7.9 years; the mean follow-up duration was 51.6 ± 32.9 months. All pre-LT patients with sarcopenia still had sarcopenia 1 year after LT; 14 (15%) patients had newly developed sarcopenia. The mean survival duration was 91.8 ± 4.2 months for non-sarcopenic patients and 80.0 ± 5.2 months for sarcopenic patients (log-rank test, p = 0.069). In subgroup analysis, newly developed sarcopenia was an independent negative predictor for post-LT survival (hazard ratio: 10.53, 95% confidence interval: 1.37–80.93, p = 0.024).

Conclusion

Sarcopenia in LT recipients did not improve in any of the previously sarcopenic patients and newly developed within 1 year in others. Newly developed sarcopenia was associated with increased mortality. Newly developed sarcopenia can be used to stratify patients with regard to the risk of post-LT mortality.

Liver Cirrhosis: Evaluation, Nutritional Status, and Prognosis

The liver is the major organ for the metabolism of three major nutrients: protein, fat, and carbohydrate. Chronic hepatitis C virus infection is the major cause of chronic liver disease. Liver cirrhosis (LC) results from different mechanisms of liver injury that lead to necroinflammation and fibrosis. LC has been seen to be not a single disease entity but one that can be graded into distinct clinical stages related to clinical outcome. Several noninvasive methods have been developed for assessing liver fibrosis and these methods have been used for predicting prognosis in patients with LC. On the other hand, subjects with LC often have protein-energy malnutrition (PEM) and poor physical activity. These conditions often result in sarcopenia, which is the loss of skeletal muscle volume and increased muscle weakness. Recent studies have demonstrated that PEM and sarcopenia are predictive factors for poorer survival in patients with LC. Based on these backgrounds, several methods for evaluating nutritional status in patients with chronic liver disease have been developed and they have been preferably used in the clinical field practice. In this review, we will summarize the current knowledge in the field of LC from the viewpoints of diagnostic method, nutritional status, and clinical outcomes.

Myostatin: expanding horizons

Myostatin is a secreted growth and differentiation factor that belongs to the TGF-β superfamily. Myostatin is predominantly synthesized and expressed in skeletal muscle and thus exerts a huge impact on muscle growth and function. In keeping with its negative role in myogenesis, myostatin expression is tightly regulated at several levels including epigenetic, transcriptional, post-transcriptional, and post-translational. New revelations regarding myostatin regulation also offer mechanisms that could be exploited for developing myostatin antagonists. Increasingly, it is becoming clearer that besides its conventional role in muscle, myostatin plays a critical role in metabolism. Hence, molecular mechanisms by which myostatin regulates several key metabolic processes need to be further explored.

Inclusion of Sarcopenia Within MELD (MELD-Sarcopenia) and the Prediction of Mortality in Patients With Cirrhosis

OBJECTIVES:

Limitations of the Model for End-Stage Liver Disease (MELD) score include its failure to assess the nutritional and functional status of cirrhotic patients. Our objectives were to evaluate the impact of sarcopenia in cirrhosis and whether the inclusion of muscularity assessment within MELD could improve the prediction of mortality in patients with cirrhosis.

METHODS:

We included 669 cirrhotic patients who were consecutively evaluated for liver transplantation. Skeletal muscle index at the third lumbar vertebra (L3 SMI) was measured by computed tomography, and sarcopenia was defined using previously published gender and body mass index–specific cutoffs. Using Cox proportional hazards regression, a novel MELD-sarcopenia score was derived.

RESULTS:

Sarcopenia was present in 298 patients (45%); sarcopenic patients had shorter median survival than non-sarcopenic patients (20±3 vs. 95±24 months, P<0.001). By Cox regression analysis adjusted for age, gender, and hepatocellular carcinoma, both MELD (hazard ratio (HR) 1.08, 95% confidence interval (CI) 1.06–1.10, P<0.001), and the L3 SMI (HR 0.97, 95% CI 0.96–0.99, P<0.001) were associated with mortality. Overall, the c-statistics for 3-month mortality were 0.82 (95% CI 0.78–0.87) for MELD and 0.85 (95% CI 0.81–0.88) for MELD-sarcopenia (P=0.1). Corresponding figures for 1-year mortality were 0.73 (95% CI 0.69–0.77) and 0.77 (95% CI 0.73–0.80), respectively (P=0.03). The c-statistics for 3-month mortality in patients with MELD<15 (0.85 vs. 0.69, P=0.02) and refractory ascites (0.74 vs. 0.71, P=0.01) were significantly higher for MELD-sarcopenia compared with MELD.

CONCLUSIONS:

Modification of MELD to include sarcopenia is associated with improved prediction of mortality in patients with cirrhosis, primarily in patients with low MELD scores. External validation of this prognostic index in larger cohorts of cirrhotic patients is warranted.

New onset of diabetes after transplantation is associated with improved patient survival after liver transplantation due to confounding factor

BACKGROUND

The influence of NODAT on survival of liver transplant recipients has not been clarified. Therefore, we evaluated the effect of NODAT on survival in LT recipients.

METHODS

Data from 352 LT patients were totally analyzed. 97 patients with pretransplant diabetes mellitus were excluded, and 255 patients without diabetes mellitus at time of transplantation were included.

RESULTS

NODAT was diagnosed in 41 patients (16.1%). There was no difference in frequency of NODAT according to the etiology of liver cirrhosis. NODAT was associated with a higher body weight (p=0.004) and BMI (p=0.002) 5years after LT, but not with weight gain (p=0.201) or increase in BMI (p=0.335) 5years after LT. HbA1c 5years after LT was significantly higher in patients with NODAT (p=0.001), but mean HbA1c still remained lower than 6.5% (6.4(±1.2) %). Patients with NODAT showed better survival rates (log rank: p=0.002) compared to LT recipients without diabetes. According to all existing knowledge of diabetes mellitus (DM) better survival cannot be a direct effect of this disease. Our results are rather influenced by an not known confounding factor (possibly recovery from cachexia) associated with better survival and NODAT, while complications of NODAT will not appear during the relatively short postoperative time and observation period (mean follow up 6.08 (±2.67) years).

CONCLUSION

NODAT is frequently diagnosed in LT recipients and is associated with an improved 5year survival after LT due to a not exactly known confounding factor.

Metabolic and molecular responses to leucine-enriched branched chain amino acid supplementation in the skeletal muscle of alcoholic cirrhosis

Skeletal muscle loss (sarcopenia) is a major clinical complication in alcoholic cirrhosis with no effective therapy. Skeletal muscle autophagic proteolysis and myostatin expression (inhibitor of protein synthesis) are increased in cirrhosis and believed to contribute to anabolic resistance. A prospective study was performed to determine the mechanisms of sarcopenia in alcoholic cirrhosis and potential reversal by leucine. In six well-compensated, stable, alcoholic patients with cirrhosis and eight controls, serial vastus lateralis muscle biopsies were obtained before and 7 hours after a single oral branched chain amino acid mixture enriched with leucine (BCAA/LEU). Primed-constant infusion of l-[ring-(2) H5 ]-phenylalanine was used to quantify whole-body protein breakdown and muscle protein fractional synthesis rate using liquid chromatography/mass spectrometry. Muscle expression of myostatin, mammalian target of rapamycin (mTOR) targets, autophagy markers, protein ubiquitination, and the intracellular amino acid deficiency sensor general control of nutrition 2 were quantified by immunoblots and the leucine exchanger (SLC7A5) and glutamine transporter (SLC38A2), by real-time polymerase chain reaction. Following oral administration, plasma BCAA concentrations showed a similar increase in patients with cirrhosis and controls. Skeletal muscle fractional synthesis rate was 9.63 ± 0.36%/hour in controls and 9.05 ± 0.68%/hour in patients with cirrhosis (P = 0.54). Elevated whole-body protein breakdown in patients with cirrhosis was reduced with BCAA/LEU (P = 0.01). Fasting skeletal muscle molecular markers showed increased myostatin expression, impaired mTOR signaling, and increased autophagy in patients with cirrhosis compared to controls (P < 0.01). The BCAA/LEU supplement did not alter myostatin expression, but mTOR signaling, autophagy measures, and general control of nutrition 2 activation were consistently reversed in cirrhotic muscle (P < 0.01). Expression of SLC7A5 was higher in the basal state in patients with cirrhosis than controls (P < 0.05) but increased with BCAA/LEU only in controls (P < 0.001).

CONCLUSIONS

Impaired mTOR1 signaling and increased autophagy in skeletal muscle of patients with alcoholic cirrhosis is acutely reversed by BCAA/LEU.

Malnutrition assessed through phase angle and its relation to prognosis in patients with compensated liver cirrhosis: a prospective cohort study

BACKGROUND

Malnutrition is a frequent complication of cirrhosis and it has been associated to more severe disease and development of complications. Phase angle is a bedside reliable tool for nutritional assessment based on conductivity properties of body tissues.

AIM

To evaluate the association between malnutrition assessed through phase angle and mortality in patients with liver cirrhosis.

METHODS

We performed a prospective cohort study in a tertiary care centre; 249 patients were enrolled with 48 months of follow-up. Clinical, nutritional (malnutrition = phase angle ≤ 4.9°) and biochemical evaluations were performed. Student's t-test and χ(2) method were used as appropriate. Kaplan-Meier curves and multivariate Cox regression were used to evaluate mortality.

RESULTS

Mean follow-up was 33.5 months. Survival analysis showed higher mortality in the malnourished group compared to the well-nourished group (p = 0.076), Kaplan-Meier curves were further stratified according to compensated and decompensated status showing higher mortality in compensated patients according to Child-Pugh (p = 0.002) and Model for End-Stage Liver Disease score (p = 0.008) when malnutrition was present. Multivariate analysis showed that malnutrition was independently associated with mortality (HR = 2.15, 1.18-3.92).

CONCLUSIONS

In our cohort, malnutrition was independently associated with mortality. This is the first study showing higher mortality in malnourished compensated cirrhotic patients.

Sarcopenia in liver cirrhosis: the role of computed tomography scan for the assessment of muscle mass compared with dual-energy X-ray absorptiometry and anthropometry

BACKGROUND

Sarcopenia evaluated by computed tomography (CT) scan at the lumbar site has been identified as a risk factor for morbidity and mortality in cirrhosis.

AIM

The aim of this study was to compare the measurement of muscle mass through CT scan, considered the gold standard, with other reliable techniques to evaluate the rate of agreement between different available methods for the assessment of muscle mass in cirrhosis. The correlation between measurements of muscle mass and of muscle strength was also investigated.

PATIENTS AND METHODS

Adult patients eligible for liver transplantation were studied. Lumbar skeletal muscle cross-sectional area was measured by CT and muscle depletion was defined using previously published cut-offs. Mid-arm muscle circumference was calculated following anthropometric measures. The Fat-Free Mass Index and the Appendicular Skeletal Muscle Index were calculated using dual-energy X-ray absorptiometry. Muscle strength was evaluated using the Hand Grip test.

RESULTS

Fifty-nine patients with cirrhosis were included. Sarcopenia was diagnosed in 76% of the patients according to CT evaluation. A significant reduction in Fat-Free Mass Index and Appendicular Skeletal Muscle Index was observed in 42-52% of the patients, whereas 52% showed a mid-arm muscle circumference less than 10th percentile. Skeletal muscle mass evaluation through CT was only weakly correlated with dual-energy X-ray absorptiometry and anthropometry evaluation. No correlation was observed between CT measurement of muscle mass and Hand Grip test.

CONCLUSION

CT scan can identify the highest percentage of sarcopenia in cirrhosis and no other techniques are actually available as a replacement. Future efforts should focus on approaches for assessing both skeletal muscle mass and function to provide a better evaluation of sarcopenia in cirrhotic patients.

Liver transplantation arrests and reverses muscle wasting

Muscle wasting, sarcopenia, is common in advanced cirrhosis and predicts adverse outcomes while awaiting and following liver transplantation. Frequent post-transplant worsening of sarcopenia has attracted recent interest. It is unknown whether this serious problem is an expected metabolic consequence of transplantation or results from confounding conditions such as recurrent allograft liver disease or avoidable post-transplant complications. To clarify this question, we studied pre- and post-transplant muscle mass in a retrospective cohort of 40 patients transplanted for three diseases - alcoholic cirrhosis, non-alcoholic steatohepatitis cirrhosis, and primary sclerosing cholangitis cirrhosis - in whom allograft disease recurrence was monitored and excluded, and who lacked common post-transplant muscle wasting complications such as sepsis, renal failure, ischemia, and cholestasis. We measured skeletal muscle index (SMI) using computed tomography before and 12-48 months after transplant. SMI as a categorical variable significantly improved, from 18 patients above the normal cutoff pre-transplant to 28 post-transplant (p = 0.008). SMI increases were greatest in patients with the lowest pre-transplant SMI (p < 0.01). As a continuous variable, mean SMI remained stable, with a non-significant trend toward improvement. We conclude that after liver transplantation sarcopenia does not progress but is arrested and frequently improves in the absence of confounding conditions.

Changes in nutritional status after liver transplantation

Chronic liver disease has an important effect on nutritional status, and malnourishment is almost universally present in patients with end-stage liver disease who undergo liver transplantation. During recent decades, a trend has been reported that shows an increase in number of patients with end-stage liver disease and obesity in developed countries. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognised. Cirrhotic patients with depleted lean body mass (sarcopenia) and fat deposits have an increased surgical risk; malnutrition may further impact morbidity, mortality and costs in the post-transplantation setting. After transplantation and liver function is restored, many metabolic alterations are corrected, dietary intake is progressively normalised, and lifestyle changes may improve physical activity. Few studies have examined the modifications in body composition that occur in liver recipients. During the first 12 mo, the fat mass progressively increases in those patients who had previously depleted body mass, and the muscle mass recovery is subtle and non-significant by the end of the first year. In some patients, unregulated weight gain may lead to obesity and may promote metabolic disorders in the long term. Careful monitoring of nutritional changes will help identify the patients who are at risk for malnutrition or over-weight after liver transplantation. Physical and nutritional interventions must be investigated to evaluate their potential beneficial effect on body composition and muscle function after liver transplantation.

Sarcopenia impairs prognosis of patients with liver cirrhosis

OBJECTIVE

Sarcopenia is characterized by the loss of skeletal muscle mass, and is reported to appear in patients with liver cirrhosis (LC). The aim of this study was to investigate the prevalence of sarcopenia in patients with LC, and to test the association between sarcopenia and patient outcomes. We also analyzed the effect of branched-chain amino acid (BCAA) supplementation on sarcopenic LC.

METHODS

Clinical and blood biochemical data of 130 patients with LC who underwent abdominal computed tomography scan were analyzed in this retrospective study. The cross-sectional area of skeletal muscles was measured at the level of the third lumbar vertebra on the scan. The skeletal muscle index was calculated to identify sarcopenia. Cirrhotic patients who were treated with BCAA supplementation of 12 g/d for ≥ 1 y were defined as the BCAA group, and the effect of BCAA on sarcopenic LC was evaluated.

RESULTS

Sixty-eight percent of all patients (82% of men and 50% of women) were diagnosed with sarcopenia. Male sex (P = 0.01) and body mass index (P < 0.0001) were predictors of sarcopenia. The multivariate Cox proportional hazards model found BCAA supplementation (hazard ratio [HR], 0.38; P = 0.01), sarcopenia (HR, 3.03; P < 0.01), and Child-Pugh classes B (HR, 2.39; P = 0.03) and C (HR, 5.49; P < 0.001) to be independently associated with mortality. The mortality of sarcopenic LC was significantly higher than that of non-sarcopenic LC (P = 0.01). Moreover, BCAA supplementation improved the survival of sarcopenic patients in subgroup analysis (P < 0.01).

CONCLUSIONS

Sarcopenia is significantly associated with mortality in patients with LC. BCAA supplementation might be associated with improved survival of such patients.

Clinical relevance of sarcopenia in patients with cirrhosis

The most commonly recognized complications in cirrhotic patients include ascites, hepatic encephalopathy, variceal bleeding, susceptibility for infections, kidney dysfunction, and hepatocellular carcinoma; however, severe muscle wasting or sarcopenia are the most common and frequently unseen complications which negatively impact survival, quality of life, and response to stressor, such as infections and surgeries. At present, D'Amico stage classification, Child-Pugh, and MELD scores constitute the best tools to predict mortality in patients with cirrhosis; however, one of their main limitations is the lack of assessing the nutritional and functional status. Currently, numerous methods are available to evaluate the nutrition status of the cirrhotic patient; nevertheless, most of these techniques have limitations primarily because lack of objectivity, reproducibility, and prognosis discrimination. In this regard, an objective and reproducible technique, such as muscle mass quantification with cross-sectional imaging studies (computed tomography scan or magnetic resonance imaging) constitute an attractive index of nutritional status in cirrhosis. Sarcopenia is part of the frailty complex present in cirrhotic patients, resulting from cumulative declines across multiple physiologic systems and characterized by impaired functional capacity, decreased reserve, resistance to stressors, and predisposition to poor outcomes. In this review, we discuss the current accepted and new methods to evaluate prognosis in cirrhosis. Also, we analyze the current knowledge regarding incidence and clinical impact of malnutrition and sarcopenia in patients with cirrhosis and their impact after liver transplantation. Finally, we discuss existing and potential novel therapeutic approaches for malnutrition in cirrhosis, emphasizing the recognition of sarcopenia in an effort to reduced morbidity related and improved survival in cirrhosis.

Post-liver transplantation sarcopenia in cirrhosis: a prospective evaluation

BACKGROUND AND AIM

Pre-transplant sarcopenia (reduced skeletal muscle mass) predicts poor outcome in cirrhosis. In contrast, whether muscle mass increases post-orthotopic liver transplantation (OLT) is not known and was studied prospectively.

METHODS

Consecutive patients who underwent a comprehensive nutritional evaluation in a liver transplant nutrition clinic were included. Core abdominal muscle area was measured on abdominal computed tomography obtained pre- and post-OLT. Age- and gender-based controls were used to define sarcopenia. Measures of body composition pre-transplant were correlated with computed tomography measurements. Predictors and clinical impact of post-OLT change in muscle area were examined. In three subjects post-OLT and three controls, expression of genes regulating skeletal muscle mass were quantified.

RESULTS

During the study period, 53 patients (M:F 41:12; age 56.9 ± 7.5 years) were followed up after OLT for 19.3 ± 9 months. Five patients died and another five had acute graft rejection. Pre-OLT sarcopenia was present in 33 (66.2%). Pre-transplant clinical characteristics including Child's score, MELD score, and nutritional status or post-transplantation immunosuppression regimen did not predict post-transplant change in muscle mass. New onset post-OLT sarcopenia developed in 14 patients. Loss of muscle mass post-OLT increased risk of diabetes mellitus and a trend toward higher mortality. Skeletal muscle expression of myostatin was higher and that of ubiquitin proteasome proteolytic components lower post-OLT than in controls.

CONCLUSIONS

Post-transplantation sarcopenia is common and could not be attributed to pre-transplant characteristics or the type or duration of post-OLT immunosuppression. Post-transplant sarcopenia contributes to adverse consequences and strategies targeting myostatin may be beneficial.

Severe muscle depletion predicts postoperative length of stay but is not associated with survival after liver transplantation

Muscle depletion or sarcopenia is associated with increased mortality in patients with cirrhosis; how it affects mortality after liver transplantation requires further study. In this study, we aimed to establish whether sarcopenia predicts increased morbidity or mortality after liver transplantation. We analyzed 248 patients with cirrhosis who had a computed tomography (CT) scan including the third lumbar vertebra before liver transplantation. Data were recovered from medical charts, the skeletal muscle cross-sectional area was measured with CT, and sarcopenia was defined with previously published sex- and body mass index-specific cutoffs. One hundred sixty-nine patients (68%) were male, and the mean age at transplantation was 55 ± 1 years. The etiologies of cirrhosis were hepatitis C virus (51%), alcohol (19%), autoimmune liver diseases (15%), hepatitis B virus (8%), and other etiologies (7%). Sarcopenia was present in 112 patients (45%), and it was more frequent in males (P = 0.002), patients with ascites (P = 0.02), and patients with higher bilirubin levels (P = 0.05), creatinine levels (P = 0.02), international normalized ratios (P = 0.04), Child-Pugh scores (P = 0.002), and Model for End-Stage Liver Disease scores (P = 0.002). The median survival period after liver transplantation was 117 ± 17 months for sarcopenic patients and 146 ± 20 months for nonsarcopenic patients (P = 0.4). Sarcopenic patients had longer hospital stays (40 ± 4 versus 25 ± 3 days; P = 0.005) and a higher frequency of bacterial infections within the first 90 days after liver transplantation (26% versus 15%, P = 0.04) in comparison with nonsarcopenic patients. In conclusion, sarcopenia is one of the most common complications in patients with cirrhosis and is predictive of longer hospital stays and a higher risk of perioperative bacterial infections after liver transplantation, but it is not associated with increased mortality.

Post-liver transplantation sarcopenia in cirrhosis: a prospective evaluation

BACKGROUND AND AIM

Pre-transplant sarcopenia (reduced skeletal muscle mass) predicts poor outcome in cirrhosis. In contrast, whether muscle mass increases post-orthotopic liver transplantation (OLT) is not known and was studied prospectively.

METHODS

Consecutive patients who underwent a comprehensive nutritional evaluation in a liver transplant nutrition clinic were included. Core abdominal muscle area was measured on abdominal computed tomography obtained pre- and post-OLT. Age- and gender-based controls were used to define sarcopenia. Measures of body composition pre-transplant were correlated with computed tomography measurements. Predictors and clinical impact of post-OLT change in muscle area were examined. In three subjects post-OLT and three controls, expression of genes regulating skeletal muscle mass were quantified.

RESULTS

During the study period, 53 patients (M:F 41:12; age 56.9 ± 7.5 years) were followed up after OLT for 19.3 ± 9 months. Five patients died and another five had acute graft rejection. Pre-OLT sarcopenia was present in 33 (66.2%). Pre-transplant clinical characteristics including Child's score, MELD score, and nutritional status or post-transplantation immunosuppression regimen did not predict post-transplant change in muscle mass. New onset post-OLT sarcopenia developed in 14 patients. Loss of muscle mass post-OLT increased risk of diabetes mellitus and a trend toward higher mortality. Skeletal muscle expression of myostatin was higher and that of ubiquitin proteasome proteolytic components lower post-OLT than in controls.

CONCLUSIONS

Post-transplantation sarcopenia is common and could not be attributed to pre-transplant characteristics or the type or duration of post-OLT immunosuppression. Post-transplant sarcopenia contributes to adverse consequences and strategies targeting myostatin may be beneficial.

Muscle wasting: a nutritional criterion to prioritize patients for liver transplantation

PURPOSE OF REVIEW

Cirrhosis is the result of the progression of necroinflammatory liver diseases leading to fibrosis, portal hypertension, and a catabolic state, which might cause muscle wasting or sarcopenia. In this review, we analyze the methods for muscularity assessment, the incidence and clinical impact of muscle wasting, and potential novel therapeutic strategies in cirrhosis. Finally, we evaluate the value of muscle wasting inclusion to conventional systems for liver transplant prioritization.

RECENT FINDINGS

Muscle wasting is present in up to 45% of patients with cirrhosis and is associated with higher risk of sepsis-related death rather than liver failure mortality. Despite the fact that muscle wasting is not included in the scores for prognosis in cirrhotic patients, as in the case of Model for End-Stage Liver Disease (MELD) or Child-Pugh, its presence should alert clinicians to the same extent as other complications do, such as ascites, hepatic encephalopathy, or variceal bleeding. Two studies have shown increased mortality risk after liver transplantation in patients with muscle wasting, whereas one study did not. Modification of MELD to include muscle wasting is associated with a modest improvement in the prediction of mortality in patients with cirrhosis.

SUMMARY

Muscle wasting is a frequent complication in cirrhosis and contributes to increased risk of sepsis-related mortality. The impact on mortality of muscle wasting after liver transplantation is controversial and needs further study. The MELD-sarcopenia score is associated with improvement in mortality prediction; however, prior to the widespread use of this composite score, validation in larger cohorts of patients with cirrhosis is necessary.

Myostatin inhibits proliferation and insulin-stimulated glucose uptake in mouse liver cells

Although myostatin functions primarily as a negative regulator of skeletal muscle growth and development, accumulating biological and epidemiological evidence indicates an important contributing role in liver disease. In this study, we demonstrate that myostatin suppresses the proliferation of mouse Hepa-1c1c7 murine-derived liver cells (50%; p < 0.001) in part by reducing the expression of the cyclins and cyclin-dependent kinases that elicit G1-S phase transition of the cell cycle (p < 0.001). Furthermore, real-time PCR-based quantification of the long noncoding RNA metastasis associated lung adenocarcinoma transcript 1 (Malat1), recently identified as a myostatin-responsive transcript in skeletal muscle, revealed a significant downregulation (25% and 50%, respectively; p < 0.05) in the livers of myostatin-treated mice and liver cells. The importance of Malat1 in liver cell proliferation was confirmed via arrested liver cell proliferation (p < 0.05) in response to partial Malat1 siRNA-mediated knockdown. Myostatin also significantly blunted insulin-stimulated glucose uptake and Akt phosphorylation in liver cells while increasing the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS), a protein that is essential for cancer cell proliferation and insulin-stimulated glucose transport. Together, these findings reveal a plausible mechanism by which circulating myostatin contributes to the diminished regenerative capacity of the liver and diseases characterized by liver insulin resistance.

Treatment to improve nutrition and functional capacity evaluation in liver transplant candidates

OPINION STATEMENT

Liver transplantation is the definitive therapy for cirrhosis, and malnutrition is the most frequent complication in these patients. Sarcopenia or loss of muscle mass is the major component of malnutrition in cirrhotics and adversely affects their outcome. In addition to the metabolic consequences, functional consequences of sarcopenia include reduced muscle strength and deconditioning. Despite nearly universal occurrence of sarcopenia and its attendant complications, there are no established therapies to prevent or reverse the same. Major reasons for this deficiency include the lack of established standardized definitions or measures to quantify muscle mass, as well as paucity of mechanistic studies or identified molecular targets to develop specific therapeutic interventions. Anthropometric evaluation, bioelectrical impedance analysis, and DEXA scans are relatively imprecise measures of muscle mass, and recent data on imaging measures to determine muscle mass accurately are likely to allow well-defined outcome responses to treatments. Resurgence of interest in the mechanisms of muscle loss in liver disease has been directly related to the rapid advances in the field of muscle biology. Metabolic tracer studies on whole body kinetics have been complemented by direct studies on the skeletal muscle of cirrhotics. Hypermetabolism and anabolic resistance contribute to sarcopenia. Reduced protein synthesis and increased autophagy have been reported in cirrhotic skeletal muscle, while the contribution of the ubiquitin-proteasome pathway is controversial. Increased plasma concentration and skeletal muscle expression of myostatin, a TGFβ superfamily member that causes reduction in muscle mass, have been reported in cirrhosis. Hyperammonemia and TNFα have been reported to increase myostatin expression and may be responsible for sarcopenia in cirrhosis. Nutriceutical interventions with leucine enriched amino acid mixtures, myostatin antagonists and physical activity hold promise as measures to reverse sarcopenia. There is even less data on muscle function and deconditioning in cirrhosis and studies in this area are urgently needed. Even though macronutrient replacement is a major therapeutic goal, micronutrient supplementation, specifically vitamin D, is expected to improve outcomes.

Posttransplant sarcopenia: an underrecognized early consequence of liver transplantation

Liver transplantation is believed to reverse the clinical and metabolic abnormalities of cirrhosis. Reduced skeletal muscle mass or sarcopenia contributes to increased mortality and adverse consequences of cirrhosis. Failure of reversal of sarcopenia of cirrhosis after liver transplantation is not well recognized. Six temporally, geographically, and methodologically distinct follow-up studies in 304 cirrhotics reported conflicting data on changes in indirect measures of skeletal muscle mass after transplantation. Distinct measures of body composition but not skeletal muscle mass were used and did not focus on the clinical consequences of sarcopenia after transplantation. A number of studies reported an initial rapid postoperative loss of lean mass followed by incomplete recovery with a maximum follow-up of 2 years. Posttransplant sarcopenia may be responsible for metabolic syndrome and impaired quality of life after liver transplantation. Potential reasons for failure to reverse sarcopenia after liver transplantation include use of immunosuppressive agents [mammalian target of rapamycin (mTOR) and calcineurin inhibitors] that impair skeletal muscle growth and protein accretion. Repeated hospitalizations, posttransplant infections, and renal failure also contribute to posttransplant sarcopenia. Finally, recovery from muscle deconditioning is limited by lack of systematic nutritional and physical-activity-based interventions to improve muscle mass. Despite the compelling data on sarcopenia before liver transplantation, the impact of posttransplant sarcopenia on clinical outcomes is not known. There is a compelling need for studies to examine the mechanisms and consequences of sarcopenia post liver transplantation to permit development of therapies to prevent and reverse this disorder.

The nutritional management of hepatic encephalopathy in patients with cirrhosis: International Society for Hepatic Encephalopathy and Nitrogen Metabolism Consensus

Nitrogen metabolism plays a major role in the development of hepatic encephalopathy (HE) in patients with cirrhosis. Modulation of this relationship is key to the management of HE, but is not the only nutritional issue that needs to be addressed. The assessment of nutritional status in patients with cirrhosis is problematic. In addition, there are significant sex-related differences in body composition and in the characteristics of tissue loss, which limit the usefulness of techniques based on measures of muscle mass and function in women. Techniques that combine subjective and objective variables provide reasonably accurate information and are recommended. Energy and nitrogen requirements in patients with HE are unlikely to differ substantially from those recommended in patients with cirrhosis per se viz. 35-45 kcal/g and 1.2-1.5g/kg protein daily. Small meals evenly distributed throughout the day and a late-night snack of complex carbohydrates will help minimize protein utilization. Compliance is, however, likely to be a problem. Diets rich in vegetables and dairy protein may be beneficial and are therefore recommended, but tolerance varies considerably in relation to the nature of the staple diet. Branched chain amino acid supplements may be of value in the occasional patient intolerant of dietary protein. Increasing dietary fiber may be of value, but the utility of probiotics is, as yet, unclear. Short-term multivitamin supplementation should be considered in patients admitted with decompensated cirrhosis. Hyponatremia may worsen HE; it should be prevented as far as possible and should always be corrected slowly.

CONCLUSION

Effective management of these patients requires an integrated multidimensional approach. However, further research is needed to fill the gaps in the current evidence base to optimize the nutritional management of patients with cirrhosis and HE.

MuRF-1 and p-GSK3β expression in muscle atrophy of cirrhosis

BACKGROUND

Chronic diseases, including cirrhosis, are often accompanied by protein-energy malnutrition and muscle loss, which in turn negatively affect quality of life, morbidity and mortality. Unlike other chronic conditions, few data are available on the molecular mechanisms underlying muscle wasting in this clinical setting.

AIMS

To assess mechanisms of muscle atrophy in patients with cirrhosis.

METHODS

Nutritional [subjective global assessment (SGA) and anthropometry] and metabolic assessment was performed in 30 cirrhotic patients awaiting liver transplantation. Rectus abdominis biopsies were obtained intraoperatively in 22 cirrhotic patients and in 10 well-nourished subjects undergoing elective surgery for non-neoplastic disease, as a control group. Total RNA was extracted and mRNA for atrogenes (MuRF-1, Atrogin-1/MAFbx), myostatin (MSTN), GSK3β and IGF-1 was assayed.

RESULTS

A total of 50% of cirrhotic patients were malnourished based on SGA, while 53% were muscle-depleted according to mid-arm muscle area (MAMA<5th percentile). MuRF-1 RNA expression was significantly increased in malnourished cirrhotic patients (SGA-B/C) vs. well-nourished patients (SGA-A) (P = 0.01). The phosphorylation of GSK3β was up-regulated in cirrhotic patients with hepatocellular carcinoma (HCC) vs. patients without tumour (P < 0.05).

CONCLUSIONS

Muscle loss is frequently found in end-stage liver disease patients. Molecular factors pertaining to signalling pathways known to be involved in the regulation of muscle mass are altered during cirrhosis and HCC.

Satellite cell functional alterations following cutaneous burn in rats include an increase in their osteogenic potential

BACKGROUND

Significant consequences of severe burn include skeletal muscle atrophy and heterotopic ossification (HO). The cellular mechanisms underlying either of these conditions are not known. Whether the functionality of satellite cells stem cells resident in skeletal muscle is affected by changes in circulatory factors following burn was determined to better understand their role in atrophy and HO.

MATERIALS AND METHODS

Serum (20%) from sham-treated animals or burned animals (40% total body surface area full-thickness burn) was used to culture satellite cells isolated from either sham or burn animals. Satellite cells were separated based on fiber type (i.e., fast-twitch or slow-twitch in some cases). To gain greater insight into the potential role for satellite cells in controlling muscle mass following burn, the effect of serum taken from burn animals on satellite cell proliferation, migration, and myogenic differentiation was evaluated. Osteogenic differentiation was assessed to evaluate the potential of satellite cells to contribute to HO.

RESULTS

Burn serum (BS) increased the proliferative capacity of cells from fast-twitch muscle, and the migratory capacity of satellite cells taken from both fast- and slow-twitch muscles. BS increased both the myogenic and osteogenic differentiation of satellite cells taken from both sham and burn animals.

CONCLUSIONS

The unexpected increase in myogenic functionality of satellite cells with BS is difficult to rectify, given the degree of atrophy that occurs. However, the increased osteogenic capacity of satellite cells with BS suggests they may play a role in burn-induced HO.