Abstract
Introduction: We have recently shown that in high cholesterol-fed rabbits, the sensitivity
of epicardial adipose tissue to changes in dietary fat is higher than that of subcutaneous
adipose tissue. Although the effects of diabetes on epicardial adipose tissue thickness have
been studied, the influence of diabetes on profile of epicardial free fatty acids (FFAs) has
not been studied. The aim of this study is to investigate the effect of diabetes on the FFAs
composition in serum and in the subcutaneous and epicardial adipose tissues in patients
undergoing coronary artery bypass graft (CABG). Methods: Forty non-diabetic and twenty
eight diabetic patients candidate for CABG with >75% stenosis participated in this study.
Fasting blood sugar (FBS) and lipid profiles were assayed by auto analyzer. Phospholipids
and non-estrified FFA of serum and the fatty acids profile of epicardial and subcutaneous
adipose tissues were determined using gas chromatography method. Results: In the
phospholipid fraction of diabetic patients’ serum, the percentage of 16:0, 18:3n-9, 18:2n-6
and monounsaturated fatty acids (MUFAs) was lower than the corresponding values of the
non-diabetics; whereas, 18:0 value was higher. A 100% increase in the amount of 18:0 and
35% decrease in the level of 18:1n-11 was observed in the diabetic patients’ subcutaneous
adipose tissue. In epicardial adipose tissue, the increase of 18:0 and conjugated linolenic
acid (CLA) and decrease of 18:1n-11, 3 (20:5n-3) and 22:6n-3 were significant; but, the
contents of arachidonic acid and its precursor linoleic acid were not affected by diabetes.
Conclusion: The fatty acids’ profile of epicardial and subcutaneous adipose tissues is not
equally affected by diabetes. The significant decrease of 16:0 and 3 fatty acids and
increase of trans and conjugated fatty acids in epicardial adipose tissue in the diabetic
patients may worsen the formation of atheroma in the related arteries.