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

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. We aimed to evaluate the relations of total body fat and body fat distribution with NAFLD in the general US population. 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. 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). 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.