Sarcopenia is the main constituent of malnutrition and is a frequent complication of chronic liver diseases, which affects up to 70% of patients with advanced liver diseases. It has been associated with adverse clinical outcomes and prognosis, including poor quality of life, development of other complications and reduction in survival rate of non-transplant patients and transplant recipients. Chronic liver disease causes alteration in glucose metabolism, lipid oxidation, ketogenesis and protein catabolism, leading to the loss of adipose and muscle tissue. In addition, inadequate nutrients intake and limited or lack of physical activity perpetuate the reduction of muscle mass. Recently, the roles and mechanisms of muscle growth-related hormones, hyperammonemia-mediated signaling pathways and gut microbiota have been recognized. In view of its impact in chronic liver disease, sarcopenia can be considered as a powerful prognostic factor and a useful additional tool in the global assessment of patients with advanced liver disease. Rational nutritional intervention, appropriate physical exercise, effective ammonia lowering strategies, hormone supplements and targeted molecular therapy (use of myostatin blockers), and liver transplantation, may improve sarcopenia, but still needs more studies for validation.
肌肉减少症是营养不良的主要组成成分，是慢性肝脏病的常见并发症，影响高达70%的晚期肝病患者，与不良临床结局和预后相关，影响患者的生活质量、发生其他并发症的风险、非移植患者和移植者术后的生存率等。慢性肝脏病引起糖代谢改变、脂肪氧化、酮体生成和蛋白质分解，导致脂肪和肌肉组织减少，加上营养物质摄入不足，身体活动受限或缺乏，使肌肉质量下降。近来，肌肉生长相关激素、高氨血症介导的信号传递通路、肠道菌群在其中发挥的作用及机制逐渐被认识。肌肉减少症是一个强有力的预后预测指标，可用于晚期肝病的整体评估。合理的营养干预、适当的运动、有效的降氨处理措施、补充激素和靶向分子治疗（如使用肌肉生长抑制素阻断剂）、肝移植等可能改善肌肉减少症，但尚需更多深入研究进一步证实。.
Keywords: Liver disease; Malnutrition; Sarcopenia.