Fatty Acid Composition of Epicardial and Subcutaneous Human Adipose Tissue

Abstract

Epicardial adipose tissue has special properties that distinguish it from the more widely studied depots of adipose tissue. We undertook this study to investigate regional differences between epicardial and subcutaneous adipose tissue fat composition, as well as associations between these measures and metabolic variables. Epicardial and subcutaneous peripheral adipose tissue were collected during coronary artery bypass grafting from 42 patients (ages 37-65) with coronary artery disease (CAD). The fatty acid composition of adipose tissue was determined by gas liquid chromatography (GLC). The saturated fatty acids, including myristic acid (14:0), palmitic acid (16:0), and stearic acid (18:0), were higher, and the unsaturated fatty acids, including palmitoleic acid (16:1n-7), oleic acid (18:1n-9), linoleic acid (18:2n-6), and linolenic acid (18:3n-3), were lower than the subcutaneous adipose tissue. The presence of hypertension was positively correlated with the 16:1n-7 (r = 0.407, P = 0.032) and 18:1n-11(r = 0.370, P = 0.027), and negatively correlated with 18:1n-9 (r = -0.367, P = 0.036) and 18:2n-6 (r = -0.446, P = 0.006) contents of epicardial adipose tissue after adjustment for body mass index. Regional differences may be observed in fatty acid composition, suggesting a depot specific impact of stored fatty acids on adipocyte function and metabolism.