Roles of human epicardial adipose tissue in coronary artery atherosclerosis

This study examined the adipocytokine-vascular interactions and link between epicardial adipose tissue and coronary artery atherosclerosis. Thirty-four patients undergoing open heart surgery were chosen randomly, and divided into group I (non-coronary artery disease group) and group II (coronary artery disease group). Blood samples were taken through peripheral vein prior to surgery. Plasma levels of a panel of proteins (adiponectin, IL-10, TNF-α) were detected by using ELISA. Epicardial adipose tissue was taken near the proximal tract of the right coronary artery and subcutaneous adipose was taken from the leg before cardiopulmonary bypassing, adiponectin and CD68 + were detected by using RT-PCR and immunohistochemistry. Our results showed that plasma adiponectin level was significantly lower in the group II as compared with group I (P<0.05). There were no differences in plasma concentration (IL-10, TNF-α, tatal-chol, HDL-chol, LDL-chol) between group I and group II. The number of CD68+ cells in epicardial adipose tissue of group II was significantly higher than that in subcutaneous adipose tissue. Adiponectin mRNA expression was 6 fold higher in subcutaneous adipose tissue than in epicardial adipose tissue of group II (P<0.01). Furthermore, the level of adiponectin mRNA in the epicardial adipose tissue in group II was also significantly lower than in group I (P<0.05). We are led to conclude that inflammation that occurs locally in epicardial adipose tissue of CAD contributes to the pathogenesis of coronary artery disease.