Sarcopenia is a complex multifactorial syndrome which could be present in older age (primary sarcopenia) or earlier in chronic disease (secondary sarcopenia). Even if in patients with chronic liver disease an association among sarcopenia and poor clinical outcomes is well known, the data available about the prevalence of sarcopenia in patients with liver cirrhosis, non-alcoholic fatty liver disease and hepatocellular carcinoma are very variable according to the populations in object and, furthermore, few data are available regarding the use of muscular ultrasound to detect this condition. The aim of this study is to define the prevalence of sarcopenia in patients with liver cirrhosis, non-alcoholic fatty liver disease and hepatocellular carcinoma in follow-up at our center and the clinical outcomes associated with this condition, and to determine the reliability of muscular ultrasound to diagnose the condition of sarcopenia through a comparison with other validated techniques such as computed tomography, magnetic resonance imaging and dual-energy X-ray absorptiometry.

Inclusion Criteria:

• Ability to express informed consent
• Diagnosis of liver cirrhosis or non-alcoholic fatty liver disease or hepatocellular carcinoma based on clinical characteristics, biochemical serum tests and liver imaging examination or liver histologic examination if available

Exclusion Criteria:

• inability to express informed consent
• pregnancy
• presence of a concomitant oncologic disease different from hepatocellular carcinoma
• presence of a concomitant gastrointestinal disease able to influence the absorption and digestion of nutrients (e.g. inflammatory bowel disease, celiac disease, short-bowel syndrome, congenital defects of metabolism)
• presence of a concomitant gastrointestinal or neurologic disease able to influence the ability of feeding (e.g. dysphagia, parkinson disease, neuromuscular diseases, diseases of the autonomic nervous system, cognitive impairment or dementia)
• chronic kidney disease from stage 3 B (IIIB) according to Kidney Disease: Improving Global Outcomes (KDIGO) classification (eGFR <45ml/min/1.73m2)
• chronic heart failure from stage Ney York Heart Association (NYHA) II
• concomitant infection from Mycobacterium Tuberculosis or human immunodeficiency virus or chronic parasitic infections