Frailty is a decline in functional reserve across multiple physiological systems. A key component of frailty is sarcopenia, which denotes a loss of skeletal muscle mass and impaired contractile function that ultimately result in physical frailty. Physical frailty/sarcopenia are frequent and contribute to adverse clinical outcomes before and after liver transplantation. Frailty indices, including the liver frailty index, focus on contractile dysfunction (physical frailty), while cross-sectional image analysis of muscle area is the most accepted and reproducible measure to define sarcopenia. Thus, physical frailty and sarcopenia are interrelated. The prevalence of physical frailty/sarcopenia is high in liver transplant candidates and these conditions have been shown to adversely impact clinical outcomes including mortality, hospitalisations, infections, and cost of care both before and after transplantation. Data on the prevalence of frailty/sarcopenia and their sex- and age-dependent impact on outcomes are not consistent in patients on the liver transplant waitlist. Physical frailty and sarcopenic obesity are frequent in the obese patient with cirrhosis, and adversely affect outcomes after liver transplantation. Nutritional interventions and physical activity remain the mainstay of management before and after transplantation, despite limited data from large scale trials. In addition to physical frailty, there is recognition that a global evaluation including a multidisciplinary approach to other components of frailty (e.g., cognition, emotional, psychosocial) also need to be addressed in patients on the transplant waitlist. Recent advances in our understanding of the underlying mechanisms of sarcopenia and contractile dysfunction have helped identify novel therapeutic targets.

虚弱是指多个生理系统的功能储备下降。虚弱的一个关键组成部分是肌肉减少症，它表示骨骼肌质量损失和收缩功能受损，最终导致身体虚弱。身体虚弱/肌肉减少症很常见，会导致肝移植前后的不良临床结果。虚弱指数，包括肝脏虚弱指数，重点关注收缩功能障碍（身体虚弱），而肌肉区域的横截面图像分析是定义肌肉减少症最被接受和可重复的措施。因此，身体虚弱和肌肉减少症是相互关联的。肝移植候选人中身体虚弱/肌肉减少症的患病率很高，这些情况已被证明会对临床结果产生不利影响，包括移植前后的死亡率、住院率、感染和护理费用。在肝移植候补名单上的患者中，关于虚弱/肌肉减少症的患病率及其对结果的性别和年龄依赖性影响的数据并不一致。肥胖肝硬化患者经常出现身体虚弱和肌肉减少性肥胖，并对肝移植后的结果产生不利影响。尽管大规模试验的数据有限，但营养干预和身体活动仍然是移植前后管理的支柱。除了身体虚弱之外，人们认识到还需要对移植候补名单上的患者进行全面评估，包括对虚弱的其他组成部分（例如认知、情感、社会心理）进行多学科方法。 我们对肌肉减少症和收缩功能障碍的潜在机制的理解的最新进展有助于确定新的治疗靶点。