Change in skeletal muscle mass is associated with hepatic steatosis in nonalcoholic fatty liver disease

The association between nonalcoholic fatty liver disease (NAFLD) and sarcopenia is known. We aimed to determine the association between skeletal muscle mass changes and NAFLD status. This retrospective single-center study analyzed patients who underwent health screening twice between November 2009 and December 2017, with a temporal gap of 6 ± 0.5 years. The degree of sarcopenia was assessed using appendicular skeletal muscle mass (ASM) adjusted for weight and body mass index (BMI). Changes in hepatic steatosis and fibrosis status were evaluated using noninvasive serum markers. Patients with a decrease in ASM/BMI (n = 353) had increased hepatic steatosis index (HSI) and fatty liver index (FLI) scores during 6 years (p < 0.05). The baseline sarcopenia group had a greater elevation in NAFLD fibrosis score (NFS) over 6 years than those without baseline sarcopenia. ASM changes over 6 years showed a negative correlation with variations in HSI (β = − 0.96 in ASM/Weight and -28.93 in ASM/BMI) and FLI (β = − 5.44 in ASM/Weight and − 167.12 in ASM/BMI). Subgroup analyses showed similar results according to sex and age. Sarcopenia may worsen steatosis and vice versa. Skeletal muscle status can be used to predict the course of NAFLD and establish individualized treatment strategies.