Sex influences the association between appendicular skeletal muscle mass to visceral fat area ratio and non-alcoholic steatohepatitis in patients with biopsy-proven non-alcoholic fatty liver disease

Sarcopenic obesity is regarded as a risk factor for the progression and development of non-alcoholic fatty liver disease (NAFLD). Since male sex is a risk factor for NAFLD and skeletal muscle mass markedly varies between the sexes, we examined whether sex influences the association between appendicular skeletal muscle mass to visceral fat area ratio (SVR), that is, an index of skeletal muscle mass combined with abdominal obesity, and the histological severity of NAFLD. The SVR was measured by bioelectrical impedance in a cohort of 613 (M/F = 443/170) Chinese middle-aged individuals with biopsy-proven NAFLD. Multivariable logistic regression and subgroup analyses were used to test the association between SVR and the severity of NAFLD (i.e. non-alcoholic steatohepatitis (NASH) or NASH with the presence of any stage of liver fibrosis). NASH was identified by a NAFLD activity score >= 5, with a minimum score of 1 for each of its categories. The presence of fibrosis was classified as having a histological stage >= 1. The SVR was inversely associated with NASH in men (adjusted OR 0 center dot 62; 95 % CI 0 center dot 42, 0 center dot 92, P = 0 center dot 017 for NASH, adjusted OR 0 center dot 65; 95 % CI 0 center dot 43, 0 center dot 99, P = 0 center dot 043 for NASH with the presence of fibrosis), but not in women (1 center dot 47 (95 % CI 0 center dot 76, 2 center dot 83), P = 0 center dot 25 for NASH, and 1 center dot 45 (95 % CI 0 center dot 74, 2 center dot 83), P = 0 center dot 28 for NASH with the presence of fibrosis). There was a significant interaction for sex and SVR (P (interaction) = 0 center dot 017 for NASH and P (interaction) = 0 center dot 033 for NASH with the presence of fibrosis). Our findings show that lower skeletal muscle mass combined with abdominal obesity is strongly associated with the presence of NASH only in men.