Impact of Visceral Fat on the Metabolic Syndrome and Nonalcoholic Fatty Liver Disease

Visceral fat has been reported to be associated with nonalcoholic fatty liver disease (NAFLD) and the metabolic syndrome (MetS). We assessed the prevalence of both NAFLD and the MetS, measured visceral fat thickness (VFT), and estimated the physical activity indexes of 224 relatively healthy hospital workers. We also investigated the associations between both VFT and physical activity index and each of NAFLD and the MetS. The MetS was diagnosed according to the guidelines outlined by the Adult Treatment Panel III, and NAFLD was diagnosed by ultrasonography. Subjects with hepatitis B and C infections and those reporting moderate alcohol consumption were excluded from the study. The prevalence of the MetS was 11.6% and that of NAFLD was 41.5%. Many subjects with the MetS had NAFLD (73.1%), and some subjects with NAFLD (20.4%) also had several components of the MetS (p=0.001). VFT was significantly increased by both the addition of components of the MetS and the severity of NAFLD (p<0.001). In addition, VFT was independently associated with NAFLD (odds ratio [OR], 1.10; 95% confidence interval [CI], 1.02-1.19) in subjects with more than 2 components of the MetS. In contrast, habitual physical activity was reversely associated with NAFLD (OR, 0.29; 95% CI, 0.10-0.87). In conclusion, an increased visceral fat content and reduced physical activity could be not only biological markers but also therapeutic targets in the treatment of NAFLD and the MetS.