Background: Not only obesity but also sarcopenia is associated with NAFLD. The influence of altered body composition on the pathophysiology of NAFLD has not been fully elucidated. The aim of this study is to determine whether skeletal muscle mass to visceral fat area ratio (SV ratio) affects NAFLD pathophysiology.
Methods: A total of 472 subjects were enrolled. The association between SV ratio and NAFLD pathophysiological factors was assessed in a cross-sectional nature by stratification analysis.
Results: When the SV ratio was stratified by quartiles (Q 1-Q 4), the SV ratio showed a negative relationship with the degree of body mass index, HOMA-IR, and liver stiffness (Q 1, 8.9 ± 7.5 kPa, mean ± standard deviation; Q 2, 7.5 ± 6.2; Q 3, 5.8 ± 3.7; Q 4, 5.0 ± 1.9) and steatosis (Q 1, 282 ± 57 dB/m; Q 2, 278 ± 58; Q 3, 253 ± 57; Q 4, 200 ± 42) measured by transient elastography. Levels of leptin and biochemical markers of liver cell damage, liver fibrosis, inflammation and oxidative stress, and hepatocyte apoptosis were significantly higher in subjects in Q 1 than in those in Q 2, Q 3, or Q 4. Moreover, fat contents in femoral muscles were significantly higher in subjects in Q 1 and the change was associated with weakened muscle strength. In logistic regression analysis, NAFLD subjects with the decreased SV ratio were likely to have an increased risk of moderate-to-severe steatosis and that of advanced fibrosis.
Conclusions: Decreased muscle mass coupled with increased visceral fat mass is closely associated with an increased risk for exacerbating NAFLD pathophysiology.
Keywords: Liver fibrosis; Liver steatosis; Non-alcoholic fatty liver disease; Pathophysiology; Skeletal muscle mass to visceral fat area ratio.