Is sarcopenia associated with hepatic encephalopathy in liver cirrhosis? A systematic review and meta-analysis

Background/purpose: Hepatic encephalopathy (HE), a major neuropsychiatric complication in advanced liver disease, is associated with poor prognosis. Sarcopenia, characterized by a decline in muscle mass, strength, and physical performance, is prevalent in liver cirrhosis. This study aims to explore whether sarcopenia is associated with HE in cirrhotic patients. Methods: PubMed and EMBASE were searched for relevant cohort and case-control studies investigating the association between sarcopenia and HE up to July 2018. Data of patients' characteristics, definition of low muscle mass, and protocols of grading/diagnosing HE were retrieved. The primary outcome was estimated by a pooled odds ratio (OR) and its 95% confidence interval (CI), using a random effect model. Results: The meta-analysis enrolled 6 studies, comprising 1795 patients. Sarcopenia was positively associated with the presence of HE (OR 2.74 with a 95% CI, 1.87 to 4.01). The association was less likely to be influenced by differences in research designs, focused study outcomes, muscle mass measurements, and protocols of grading/diagnosing HE. There was lack of evidence supporting higher serum ammonia levels in patients with sarcopenia. Conclusion: In patients with liver cirrhosis, there is a significant association between sarcopenia and HE. A greater number of prospective studies are necessary to clarify whether the association remains even after adjusting relevant confounders and to suggest effective prevention of HE in patients with coexisting sarcopenia. Keywords: Liver, Malnutrition, Skeletal muscle, Neurology, Ammoni