Superficial vs Deep Subcutaneous Adipose Tissue: Sex-Specific Associations With Hepatic Steatosis and Metabolic Traits

Context: Subcutaneous adipose tissue (SAT) is not homogeneous, as the fascia scarpa separates the deep SAT (dSAT) from the superficial SAT (sSAT). Objective: The aim of this study is to evaluate the sex-specific associations of sSAT and dSAT with hepatic steatosis and metabolic syndrome in overweight individuals. Methods: We recruited 285 individuals with a body mass index (BMI) greater than or equal to 27 and aged 55 to 81 years. Abdominal magnetic resonance imaging was performed around level L4 to L5 to measure visceral adipose tissue (VAT), dSAT, and sSAT volumes. The amount of hepatic fat was quantified by MR spectroscopy. Results: Men had significantly higher volumes of VAT (122.6 [cm.sup.3] vs 98.7 [cm.sup.3], P < .001) and had only half the volume of sSAT compared to women adjusted for BMI (50.3 [cm.sup.3] in men vs 97.0 [cm.sup.3] in women, P < .001). dSAT correlated significantly with hepatic fat content in univariate analysis (standardized [beta] = .190, P < .05), while VAT correlated significantly with hepatic steatosis in a multivariate model, adjusted for age, alcohol use, and other abdominal fat compartments (standardized [beta] = .184, P = .037). Moreover, dSAT in men correlated negatively with HDL cholesterol (standardized [beta] = -0.165, P = .038) in multivariate analyses. In women with a BMI between 30 and 40, in a multivariate model adjusted for age, alcohol use, and other abdominal fat compartments, VAT correlated positively (standardized [beta] = -.404, P = .003), and sSAT negatively (standardized [beta] = -.300, P = .04) with hepatic fat content. Conclusion: In men, dSAT is associated with hepatic steatosis and adverse metabolic traits, such as lower HDL cholesterol levels, whereas in women with obesity sSAT shows a beneficial relation with respect to hepatic fat content. Key Words: liver steatosis, fat distribution, metabolic syndrome, obesity