Background: Sarcopenia is diagnosed with the skeletal muscle index (SMI) or the sarcopenia index (SI). We previously reported that the ratio of skeletal muscle mass to body fat mass (SF ratio) was a novel index of sarcopenia in patients with non-alcoholic fatty liver disease (NAFLD). The aim of this retrospective study was to evaluate sarcopenia with these indices in patients with NAFLD.
Methods: One hundred and fifty-six consecutive patients with biopsy-proven NAFLD and alanine aminotransferase (ALT) >40 IU/L were enrolled. Liver function and body composition were evaluated in 121 patients after 12 months. We evaluated the relationship between histological findings, changes in liver function, and the SMI, SI, and SF ratio.
Results: Of the 156 patients enrolled, 13.5% and 26.3% were diagnosed with sarcopenia with the SMI and SI. In patients with hepatic fibrosis stage <2, the SI and the SF ratio were significantly greater than in patients with fibrosis stage ≥2. There was no difference in SMI between groups. In the cohort assessed at baseline and 12 months later, transaminase activity and SMI decreased significantly, and the SF ratio increased over time. A multivariate analysis revealed the presence of the PNPLA3 G allele and an increase in SF ratio (odds ratio, 7.406) as predictive factors of ALT reduction >30% from baseline.
Conclusions: Due to the high prevalence of obesity, we should consider both skeletal muscle mass and body fat mass in the diagnosis and treatment of NAFLD. The SF ratio could be a useful index in sarcopenic NAFLD.
Keywords: NAFLD; PNPLA3; SF ratio; SI; sarcopenia.
© 2019 The Japan Society of Hepatology.