Sarcopenia and chronic liver diseases.

INTRODUCTION: Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which is commonly associated with various chronic diseases, including chronic liver diseases. Growing lines of evidence indicate that sarcopenia not only correlates with the clinical outcomes and survival of patients undergoing liver transplant, but also serves as a prognostic factor for candidates of liver transplantation and patients with hepatocellular carcinoma. Areas covered: In this review, we conducted a narrative review and search of literature from PubMed, Ovid MEDLINE, and the Cochrane Library database up to August 2018. Studies relevant to the emerging data of sarcopenia and chronic liver diseases were examined and discussed. Expert commentary: Although sarcopenia has been shown to play a vital role in the outcomes of cirrhotic patients with or without liver transplant, its impact on non-cirrhotic patients remains unclear and deserves future research efforts. To develop an effective and practical measurement of sarcopenia has become an urgent issue in the management of patients with chronic liver diseases. ABBREVIATIONS: HCC: hepatocellular carcinoma; L3SMI: third lumbar vertebra skeletal muscle index; NAFLD: nonalcoholic fatty liver disease; VAT: visceral adipose tissue; PMA: psoas muscle area; LT: liver transplantation; AUC: area under the curve; LC: liver cirrhosis; SPPB: short physical performance battery; HU: Hounsfield units; ASM: appendicular skeletal muscle; SMI: skeletal muscle index; FLI: fatty liver index; PCLD: polycystic liver disease; DEXA: dual energy X-ray absorptiometry; BCAAs: branched-chain amino acids; BIA: bioelectrical impedance analysis; CT: computed tomography; OS: overall survival; CSA: cross-sectional area; NASH: nonalcoholic steatohepatitis; TPMT: transversal psoas muscle thickness; IMAC: intramuscular adipose tissue content; LDLT: living donor liver transplantation; PMI: psoas muscle mass index; PMTH: psoas muscle thickness by height; TPA: total psoas area; OLT: orthotopic liver transplantation; 6MWD: Six-minute walk distance; HRQOL: health-related quality of life; SMA: skeletal muscle area.