Sarcopenia in chronic liver diseases: a translational overview.

Introduction: Sarcopenia refers to a progressive and generalized muscle mass and strength loss. In liver diseases, it has been related to worse outcomes and high risk of decompensations.

Areas Covered: Sarcopenia is caused by a set of cellular processes in the muscle such as denervation, mitochondrial dysfunction, endotoxemia and inflammation; which are manifested through the alteration of several proteolytic pathways such as lysosomal, proteasomal and caspase systems. In autophagy, myostatin and oxidative stress; such as hyperammonemia, contributes importantly to liver sarcopenia through loss of muscle mass already demonstrated in and models. In addition, hormones and the regulation of the intestinal microbiota, influence in a not less important magnitude. In the clinical setting, early identification of sarcopenia has been established as a mandatory item to prevent progression of muscle mass loss; however, diagnostic methods have extreme variation according to methodology, population, etiology and severity of liver disease. Reversing sarcopenia should be an integral therapeutic strategy.

Expert Opinion: Clinical and nutritional interventions should be adapted to liver injury etiology and stage of disease, each of them shares a similar sarcopenia development pathway. There are specific biomarkers that condition or exacerbate loss of skeletal muscle.