Background: The aim of this retrospective study was to determine the effect of skeletal muscle and body fat on liver function in patients with nonalcoholic fatty liver disease (NAFLD) diagnosed by liver biopsy.
Methods: Among the 219 patients with NAFLD enrolled in this study was a cohort of 139 patients who had their body composition measured with Inbody720 at baseline and at ≥ 1 year postbaseline, to elucidate the relationship between liver function and changes in skeletal muscle and body fat mass. Multivariate analysis was used to identify factors influencing low skeletal muscle mass index (SMI, defined as 7 kg/m2 in men, and 5.7 kg/m2 in women) and the skeletal muscle mass to body fat mass ratio (SF ratio).
Results: Of the 219 patients enrolled, 27 (12.3%) had a low SMI. Patient age (> 70 years) and female gender were identified as risk factors for low SMI. Hepatic fibrosis was not associated with SMI. In the cohort followed up at baseline and 12 months later, transaminase activity, body fat mass, and SMI significantly decreased over time. Changes in the SF ratio were significantly associated with changes in liver function. An increase in the SF ratio [hazard ratio (HR) 10.99 in men, 6.849 in women] was a predictor of reduced ALT, independent of age and other backgrounds.
Conclusions: In the patients with NAFLD, SMI was decreased, even in the early stages of NAFLD. Therapeutic strategies for NAFLD require a reduction in body fat mass and the maintenance of skeletal muscle is also needed.
Keywords: Body fat mass; NAFLD; SF ratio; SMI.