Sarcopenia in the Cirrhotic Patient: Current Knowledge and Future Directions

Sarcopenia and frailty: An in-depth analysis of the pathophysiology and effect on liver transplant candidates

Cirrhosis represents the end stage of chronic liver disease, significantly reducing life expectancy as it progresses from a compensated to a decompensated state, leading to serious complications. Recent improvements in medical treatment have created a shift in cirrhosis management. Various causes, including hepatitis viruses, alcohol consumption, and fatty liver disease, contribute to cirrhosis and are closely linked to liver cancer. The disease develops through hepatocyte necrosis and regeneration, resulting in fibrosis and sinusoidal capillarization, leading to portal hypertension and complications such as ascites, hepatic encephalopathy, and organ dysfunction. Cirrhosis also holds an increased risk of hepatocellular carcinoma. Diagnosing cirrhosis involves assessing fibrosis scores through blood tests and measuring liver stiffness through elastography. Liver transplantation is the definitive treatment for end-stage liver disease and acute liver failure.

Dynamic skeletal muscle loss and its predictive role on 90-day mortality in patients with acute-on-chronic liver failure

Background

Low skeletal muscle mass is an independent risk factor for increased mortality in patients with acute-on-chronic liver failure (ACLF). However, no study has evaluated the temporal changes in muscle mass during the course of ACLF. Therefore, this study aimed to investigate the dynamic changes in muscle mass and their prognostic role in patients with ACLF.

Methods

A retrospective analysis was conducted on consecutive patients with ACLF who underwent two or more abdominal computed tomography examinations within 90 days of admission. The percentage change rates of the skeletal muscle index at the third lumbar vertebra (L3-SMI) were calculated as (L3-SMIfinal - L3-SMIinitial)/(L3-SMIinitial) × 100%.

Results

A total of 154 patients with ACLF were included. During the course of ACLF, the percentage change rates of L3-SMI at 2-7, 8-14, 15-30, 31-60, and 61-90 days were - 0.83 ± 4.43, -3.76 ± 4.40, -7.30 ± 5.89, -10.10 ± 7.45, and - 5.53 ± 9.26, respectively. Significant reductions in L3-SMI were noted in patients with severe conditions compared to other patients at 2-7 days and 15-30 days. Moreover, the rate of decrease in L3-SMI in patients with a lower respiratory quotient (RQ) was significantly greater than that in patients with a normal RQ at 2-7 days and 15-30 days. Additionally, high muscle loss (HR 2.059; 95% CI 1.122-3.780, p = 0.020), rather than pre-existing sarcopenia (HR 1.430; 95% CI 0.724-2.826, p = 0.303) at baseline, was independently associated with 90-day mortality.

Conclusion

Deterioration in muscle mass is associated with disease severity and poor nutritional status and serves as a more effective predictor of adverse short-term outcomes in patients with ACLF. These findings underscore the importance of dynamic evaluation of muscle loss and emphasize the necessity of reversing muscle loss in patients with ACLF.

Pathophysiological-Based Nutritional Interventions in Cirrhotic Patients with Sarcopenic Obesity: A State-of-the-Art Narrative Review

In recent decades, following the spread of obesity, metabolic dysfunction has come to represent the leading cause of liver disease. The classical clinical presentation of the cirrhotic patient has, therefore, greatly changed, with a dramatic increase in subjects who appear overweight or obese. Due to an obesogenic lifestyle (lack of physical activity and overall malnutrition, with an excess of caloric intake together with a deficit of proteins and micronutrients), these patients frequently develop a complex clinical condition defined as sarcopenic obesity (SO). The interplay between cirrhosis and SO lies in the sharing of multiple pathogenetic mechanisms, including malnutrition/malabsorption, chronic inflammation, hyperammonemia and insulin resistance. The presence of SO worsens the outcome of cirrhotic patients, affecting overall morbidity and mortality. International nutrition and liver diseases societies strongly agree on recommending the use of food as an integral part of the healing process in the comprehensive management of these patients, including a reduction in caloric intake, protein and micronutrient supplementation and sodium restriction. Based on the pathophysiological paths shared by cirrhosis and SO, this narrative review aims to highlight the nutritional interventions currently advocated by international guidelines, as well as to provide hints on the possible role of micronutrients and nutraceuticals in the treatment of this multifaceted clinical condition.

Frailty in end-stage liver disease: Understanding pathophysiology, tools for assessment, and strategies for management

Frailty and sarcopenia are frequently observed in patients with end-stage liver disease. Frailty is a complex condition that arises from deteriorations across various physiological systems, including the musculoskeletal, cardiovascular, and immune systems, resulting in a reduced ability of the body to withstand stressors. This condition is associated with declined resilience and increased vulnerability to negative outcomes, including disability, hospitalization, and mortality. In cirrhotic patients, frailty is influenced by multiple factors, such as hyperammonemia, hormonal imbalance, malnutrition, ascites, hepatic encephalopathy, and alcohol intake. Assessing frailty is crucial in predicting morbidity and mortality in cirrhotic patients. It can aid in making critical decisions regarding patients' eligibility for critical care and transplantation. This, in turn, can guide the development of an individualized treatment plan for each patient with cirrhosis, with a focus on prioritizing exercise, proper nutrition, and appropriate treatment of hepatic complications as the primary lines of treatment. In this review, we aim to explore the topic of frailty in liver diseases, with a particular emphasis on pathophysiology, clinical assessment, and discuss strategies for preventing frailty through effective treatment of hepatic complications. Furthermore, we explore novel assessment and management strategies that have emerged in recent years, including the use of wearable technology and telemedicine.

Liver Transplantation: Protocol for Recipient Selection, Evaluation, and Assessment

Liver transplantation (LT) is the definitive therapy for patients with end-stage liver disease, acute liver failure, acute-on-chronic liver failure, hepatocellular carcinoma, and metabolic liver diseases. The acceptance of LT in Asia has been gradually increasing and so is the expertise to perform LT. Preparing a patient with cirrhosis for LT is the most important aspect of a successful LT. The preparation for LT begins with the first index decompensation for a patient with cirrhosis. Patients planned for LT should undergo a thorough screening for infections, and a complete cardiac, pulmonology, and psychosocial evaluation pre-LT. In this review, we discuss the indications and contraindications of LT and the evaluation and assessment of patients with liver disease planned for LT.

Evaluation and Management of Nutritional Consequences of Chronic Liver Diseases

Liver diseases are the major predisposing conditions for the development of malnutrition, sarcopenia, and frailty. Recently, the mechanism of the onset of these complications has been better established. Regardless of the etiology of the underlying liver disease, the clinical manifestations are common. The main consequences are impaired dietary intake, altered macro- and micronutrient metabolism, energy metabolism disturbances, an increase in energy expenditure, nutrient malabsorption, sarcopenia, frailty, and osteopathy. These complications have direct effects on clinical outcomes, survival, and quality of life. The nutritional status should be assessed systematically and periodically during follow-up in these patients. Maintaining and preserving an adequate nutritional status is crucial and should be a mainstay of treatment. Although general nutritional interventions have been established, special considerations are needed in specific settings such as decompensated cirrhosis, alcohol-related liver disease, and metabolic-dysfunction-associated fatty liver disease. In this review, we summarize the physiopathology and factors that impact the nutritional status of liver disease. We review how to assess malnutrition and sarcopenia and how to prevent and manage these complications in this setting.

Sarcopenia in cirrhosis: Prospects for therapy targeted to gut microbiota

Decreased muscle mass and function, also known as sarcopenia, is common in patients with cirrhosis and is associated with a poor prognosis. Although the pathogenesis of this disorder has not been fully elucidated, a disordered gut-muscle axis probably plays an important role. Decreased barrier function of the gut and liver, gut dysbiosis, and small intestinal bacterial overgrowth (SIBO) can lead to increased blood levels of ammonia, lipopolysaccharides, pro-inflammatory mediators, and myostatin. These factors have complex negative effects on muscle mass and function. Drug interventions that target the gut microbiota (long-term use of rifaximin, lactulose, lactitol, or probiotics) positively affect most links of the compromised gut-muscle axis in patients with cirrhosis by decreasing the levels of hyperammonemia, bacterial translocation, and systemic inflammation and correcting gut dysbiosis and SIBO. However, although these drugs are promising, they have not yet been investigated in randomized controlled trials specifically for the treatment and prevention of sarcopenia in patients with cirrhosis. No data exist on the effects of fecal transplantation on most links of gut-muscle axis in cirrhosis; however, the results of animal experimental studies are promising.

[Sarcopenia in chronic liver diseases]

BACKGROUND

Sarcopenia is a progressive and generalized disorder of the skeletal musculature that involves the loss of skeletal muscle mass and function. Patients with chronic liver disease frequently have sarcopenia in advanced stages of the disease; however, there is an increased prevalence of sarcopenia not only in liver cirrhosis but also in earlier stages of disease, e.g., in non-alcoholic fatty liver disease (NAFLD).

RESULTS

Sarcopenia is an independent prognostic risk factor for morbidity and mortality in patients with liver cirrhosis. The pathogenesis of sarcopenia is multifactorial and in chronic liver diseases a lower oral energy intake, altered ammonia metabolism, hormonal imbalances and a chronic low-grade inflammatory state are important. When the screening test is positive, determination of the muscle strength, e.g., measurement of hand grip strength, is recommended for the diagnostic approach. Lower muscle strength leads to further measurement of muscle mass to confirm the diagnosis of sarcopenia. In patients with chronic liver disease abdominal imaging by computed tomography or magnetic resonance imaging is particularly suitable for this. The severity of sarcopenia is classified by the physical performance. Therapeutic strategies for the treatment of sarcopenia include nutritional therapy as well as exercise therapy.

CONCLUSION

Patients with chronic liver diseases frequently have sarcopenia. This is an independent prognostic risk factor. Therefore, sarcopenia should be considered in the diagnostics and therapeutic approaches.