Sex-related association of NAFLD and liver fibrosis with body fat distribution in the general US population

Background: Few population-based studies have investigated the association between body fat distribution and the risk of nonalcoholic fatty liver disease (NAFLD) and significant liver fibrosis. Objectives: We aimed to evaluate the relations of total body fat and body fat distribution with NAFLD in the general US population. Methods: This is a cross-sectional, population-based study based on the 2017-2018 cycle of the NHANES. Participants aged 18-59 y without known liver conditions or significant alcohol consumption were studied by DXA and vibration-controlled transient elastography to assess body composition and liver steatosis and fibrosis, respectively. Multivariable logistic regression analysis was performed to evaluate the contribution of BMI and android:gynoid ratio (A:G ratio) to the prevalence of liver steatosis and fibrosis in males and females. Results: Weighted prevalence of steatosis was 41.5% and 29.9% among the 1115 males and 1113 females included in the study, respectively, whereas 7.0% of males and 4.0% of females had elastographic evidence of significant liver fibrosis. After adjustment for age, race-Hispanic origin, diabetes, cigarette smoke, and BMI, a higher A:G ratio was associated with increased odds of steatosis in both males (OR: 1.79; 95% CI: 1.07, 2.99; P = 0.029) and females (OR: 1.95; 95% CI: 1.11, 3.41; P = 0.023). Conversely, a significant association between A:G ratio and liver fibrosis was identified in females (OR: 2.09; 95% CI: 1.11, 3.97; P = 0.026), but not in males (OR: 0.56; 95% CI: 0.29, 1.08; P = 0.078). Conclusions: Independently from BMI, an android fat deposition pattern is associated with increased prevalence of NAFLD in both sexes, whereas the effect on fibrosis was only evident in females.