Obesity, Hepatic Steatosis, and Their Impact on Fat Infiltration of the Trunk Musculature Using Unenhanced Computed Tomography

Objectives: The aim of the study was to assess whether hepatic steatosis predicts muscle fat content independent of body mass index (BMI). Methods: Regions of interest were drawn over several trunk muscles and over the right lobe of the liver to obtain the computed tomography (CT) density in 100 subjects with unenhanced CT studies of the abdomen and pelvis. Univariate and multivariate linear regression were used to examine the associations between BMI and hepatic steatosis and between BMI and trunk muscle density. Results: Body mass index was associated with trunk muscle fat (P < 0.05) and hepatic steatosis (P < 0.05). Computed tomography density of the liver correlated with that of each trunk muscle (P < 0.05). After adjusting for age, sex, and BMI, hepatic steatosis was associated with increased trunk muscle fat content in the psoas only. Conclusions: The association between muscle fat in most trunk muscles and hepatic steatosis is due to underlying BMI. However, hepatic steatosis predicted psoas muscle fat content independent of BMI (P < 0.05).