Lipid profile of epicardial adipose tissue in obese individuals – preliminary data

With its endocrine and metabolic activity, visceral adipose tissue (VAT) is more than a storage organ. Research shows that VAT has a role in the development of cardiovascular disorders. The influence of epicardial adipose tissue (EAT, a subset of VAT) morphology on cardiovascular function and health is still limited (1). Furthermore, the data on the content of lipids and their metabolites in the EAT depending on the amount of VAT are scarce or non-existent. The aim of this pilot study was to characterize lipids and their metabolites in EAT in relation to visceral obesity. EAT from 6 obese and 6 non-obese subjects (based on waist circumference) was collected post-mortem and homogenized in 20mM ammonium acetate buffer using Dounce homogenizer. Lipid extraction from the homogenate was performed with Blight and Dyer’s two-phase method (2). Both polar and nonpolar phases were imaged in positive and negative imaging mode on Bruker UltrafleXtreme MALDI-TOF device in the 200-1500 m/z range. The matrices used were dihydrobenzoic acid and 9-aminoacridine, respectively. Collected data were analyzed using R statistical software with FELLA and KEGGREST packages. Out of 106 determined putative metabolites, C08320 – Lignoceric acid was 2.37 times more abundant in the obese group (p=0.0396). Out of the 106 molecules, 13.5% were upregulated, 11.9% were downregulated in the obese group and the rest were unchanged compared to the non-obese group. FELLA enrichment revealed alteration in fatty acid biosynthesis and degradation accompanied with upregulation in glycosphingolipid biosynthesis. Preliminary data indicate a metabolic difference in EAT of obese patients. None of the subjects suffered from Gaucher’s disease, so it may be assumed that lignoceric acid is exogenous in nature (from food). This also explains upregulation in glycosphingolipid biosynthesis, lignoceric acid being one of its precursors. The preliminary data showed some changes in EAT of obese patients which are potentially food-related. Larger groups are necessary to draw more definite conclusions.