The discrepancy of aromatase expression in epicardial adipose tissue between CHD and non-CHD patients.

Abstract

Epicardial adipose tissue (EAT) aromatase converts androstenedione and other adrenal androgens into oestrogens. The locally produced oestradiol (E2) may have cardiovascular protective effects. Little is known about the relationship between EAT aromatase level and coronary heart disease (CHD). Here, we compared EAT aromatase levels in CHD versus non-CHD patients and assessed the relationship between EAT aromatase levels and lesion degree in the coronary arteries. EAT and blood specimens were obtained from patients undergoing thoracotomy prior to cardiopulmonary bypass. Serum E2 levels were obtained from our hospital laboratory. EAT aromatase expression was determined by RT-qPCR and ELISA assays. All patients underwent coronary angiography and the level of coronary lesions was evaluated with the SYNTAX score. Compared with non-CHD patients, CHD patients had lower EAT aromatase mRNA and protein levels. In the CHD patients, EAT aromatase and oestrogen levels negatively correlated with the severity of coronary artery disease. Our data revealed that reduced EAT aromatase levels correlated with coronary atherosclerotic lesions. Reduced EAT aromatase protein levels may aggravate the severity of atherosclerosis. Future studies should investigate the mechanisms regulating aromatase expression in epicardial fat.