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 cm3 vs 98.7 cm3, P < .001) and had only half the volume of sSAT compared to women adjusted for BMI (50.3 cm3 in men vs 97.0 cm3 in women, P < .001). dSAT correlated significantly with hepatic fat content in univariate analysis (standardized ß = .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 ß = .184, P = .037). Moreover, dSAT in men correlated negatively with HDL cholesterol (standardized ß = -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 ß = -.404, P = .003), and sSAT negatively (standardized ß = -.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.

Noninvasive Quantitative Assessment of Hepatic Steatosis by Proton Magnetic Resonance Spectroscopy Among Adult Patients Receiving Home Parenteral Nutrition.

BACKGROUND: Intestinal failure-associated liver disease is a frequent complication in patients with chronic intestinal failure (CIF), with steatosis as a dominant feature in adults. Proton magnetic resonance spectroscopy (1H-MRS) is a noninvasive method to quantify liver fat content (LFC). In this study, LFC was assessed with 1H-MRS, taking into account the possible accumulation of paramagnetic components of home parenteral nutrition (HPN) that may disturb these measurements. METHODS: LFC was measured in 15 adult CIF patients who had been receiving HPN for >6 months. 1H-MR spectra were obtained with a 3 Tesla magnetic resonance (MR) system, with a method correcting for the presence of paramagnetic ions. Patients with low (<5%) versus high (≥5%, steatosis) LFC were compared with nonparametric statistical tests. RESULTS: 1H-MRS analysis revealed steatosis in 5 patients (median, 10.3%), while 10 patients had normal LFC (median, 0.9%). In all patients, the 1H-MRS results indicated the presence of various amounts of paramagnetic constituents in the liver. Patients with steatosis had higher alanine aminotransferase values than patients without steatosis (median, 60 vs 28 U/L). Unexpectedly, in the steatosis group, the frequency of HPN use was lower, with significant lower total HPN and carbohydrate calories. In 1 patient, MR spectra were of inferior quality, with broadened resonances after infusion with a ferric compound. CONCLUSION: 1H-MRS enables reliable noninvasive assessment of LFC in patients receiving long-term HPN, if correcting for possible accumulation of paramagnetic components in the liver. However, LFC determination by 1H-MRS is not recommended after a recent ferric compound infusion.