Introduction and objectives: The high level of metabolic activity present in visceral adipose tissue is associated with the development of atherothrombosis. Subcutaneous adipose tissue secretes larger quantities of the adipocytokines leptin and adiponectin than visceral adipose tissue. Epicardial adipose tissue secretes inflammatory mediators, and the resulting proinflammatory activity is greater than that associated with subcutaneous adipose tissue. The aim of this study was to compare adiponectin and leptin expression in human epicardial and subcutaneous adipose tissue.
Methods: Samples of both epicardial and subcutaneous adipose tissue were taken from 46 patients who were undergoing heart surgery, coronary artery bypass surgery, or aortic or mitral valve replacement. Levels of protein and gene expression of leptin and adiponectin were assessed immunohistochemically and by RT-PCR, respectively. Levels of mRNA expression in the 2 adipose tissue types were compared by real-time quantitative PCR.
Results: Significant differences were found between adiponectin and leptin mRNA expression in epicardial and subcutaneous adipose tissue, with epicardial adipose tissue exhibiting lower levels of adiponectin and leptin expression. Moreover, adiponectin and leptin mRNA expression in epicardial adipose tissue was higher in women than men.
Conclusions: Adiponectin and leptin expression is lower in epicardial than in subcutaneous adipose tissue. Moreover, there are differences in adiponectin and leptin expression in epicardial adipose tissue between women and men.