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.