RESUMO
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, w3 (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 w3 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.
RESUMO
BACKGROUND: We have shown that the fatty acid profile of epicardial adipose tissue (EAT) in patients with obstructed coronary vessels is different from that of the subcutaneous adipose tissue (SAT). The diversity and amount of fatty acids in the adipose tissue can be affected by the component of the lipids in diet. As a result, this study investigated the influence of a high cholesterol regime on EAT and subcutaneous adipose tissue fatty acids profile in rabbits. METHODS: Sixteen New Zealand white rabbits were randomly divided into two equal groups. The control group received a normal standard diet, whereas the test group was fed with the high cholesterol regime for 2 months. At the end of this period, the rabbits were anesthetized, 1-5 mg of EAT and SAT were removed, and their fatty acids content was determined. RESULTS: The high cholesterol regime caused a significant increase in low-density lipoprotein (LDL) and triglycerides levels and a marked decrease in high-density lipoprotein (HDL) concentration. After 2 months, in the EAT, fatty acids 16:0 and 18:1t and saturated fatty acid (SFA) showed a significant increase (P<0.05), whereas, fatty acids 12:0, 18:1, 18:2, and 18:3, monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), ω3, and ω6 had a significant decrease (P<0.05). In SAT, fatty acids 18:3, 20:4, 22:6, MUFA, and ω3 decreased and PUFA, SFA, and ω6 significantly increased (P<0.05). CONCLUSION: Consumption of a high cholesterol regime for 2 months resulted in a significant increase in atherogenic fatty acids and a decrease in antiatherogenic ones in the EAT. EAT is very sensitive to lipid changes of the regime comparing to SAT.
