Sarcopenia Among Patients With Nonalcoholic Fatty Liver Disease (NAFLD) Is Associated With Advanced Fibrosis

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) and sarcopenia can be associated with advanced liver disease. Our aim was to assess the association between sarcopenia and the risk of fibrosis among patients with NAFLD.METHODS: We used the National Health and Nutrition Examination Survey (2017-2018). NAFLD was defined by transient elastography without other causes of liver disease or excessive alcohol use. Significant fibrosis (SF) and advanced fibrosis (AF) were defined by liver stiffness greater than 8.0 kPa and greater than 13.1 kPa, respectively. Sarcopenia was defined using the Foundation for the National Institutes of Health definition.RESULTS: Of the total cohort (N [ 2422), 18.9% had sarcopenia, 9.8% had obese sarcopenia, 43.6% had NAFLD, 7.0% had SF, and 2.0% had AF. Moreover, 50.1% had neither sarcopenia nor NAFLD, 6.3% had sarcopenia without NAFLD, 31.1% had NAFLD without sarcopenia, and 12.5% had NAFLD with sarcopenia. Compared with individuals without NAFLD or sarcopenia, individuals with sarcopenic NAFLD had higher rates of SF (18.3% vs 3.2%) and AF (7.1% vs 0.2%). In the absence of sarcopenia, compared with individuals without NAFLD, individuals with NAFLD have a significantly increased risk of SF (odds ratio, 2.18; 95% CI, 0.92-5.19). In the presence of sarcopenia, NAFLD was associated with an increased risk of SF (odds ratio, 11.27; 95% CI, 2.79- 45.56). This increase was independent of metabolic components. The proportion of SF that is attributable to the interaction of NAFLD and sarcopenia was 55% (attributable proportion, 0.55; 95% CI, 0.36-0.74). Increased leisure time physical activity was associated with a lower risk of sarcopenia.CONCLUSIONS: Patients with sarcopenic NAFLD are at risk for SF and AF. Increased physical activity and a healthy diet targeted to improve sarcopenic NAFLD could reduce the risk of significant fibrosis.