The Leg Fat to Total Fat Ratio Is Associated with Lower Risks of Non-Alcoholic Fatty Liver Disease and Less Severe Hepatic Fibrosis: Results from Nationwide Surveys (KNHANES 2008–2011)

BACKGROUND: The prevalence of non-alcoholic fatty liver disease (NAFLD) has rapidly increased worldwide. The aim of this study was to investigate whether there is an independent relationship between regional fat distribution, especially leg fat mass, and the presence of NAFLD using nationally representative data in Korea. METHODS: This cross-sectional study analyzed data from 14,502 participants in the Korea National Health and Nutrition Examination Survey 2008 to 2011. Total fat mass, leg fat mass, and appendicular skeletal muscle mass were measured by dual-energy X-ray absorptiometry. Validated NAFLD prediction models and scoring systems for hepatic fibrosis were used. RESULTS: The leg fat to total fat (LF/TF) ratio showed a negative relationship with many factors, including body mass index, waist circumference, blood pressure, fasting blood glucose, and liver enzyme levels. When the LF/TF ratio and indices of hepatic steatosis were stratified by quartiles, the LF/TF ratio showed a negative correlation with the scoring systems that were used. The LF/TF ratio showed better accuracy in predicting NAFLD than total fat mass or leg fat mass alone. After adjusting for various traditional and lifestyle factors, a low LF/TF ratio remained a risk factor for NAFLD. Among NAFLD subjects, the LF/TF ratio showed a negative relationship with hepatic fibrosis. CONCLUSION: A lower LF/TF ratio was markedly associated with a higher risk of hepatic steatosis and advanced hepatic fibrosis using various predictive models in a Korean population. Therefore, the LF/TF ratio could be a useful anthropometric parameter to predict NAFLD or advanced hepatic fibrosis.