Abstract 4265: Epicardial Adipose Tissue-Derived Adipokines In Obesity And Coronary Artery Disease
Introduction: Pro- and anti-inflammatory products of adipose tissue (adipokines), especially of epicardial fat that surrounds the coronary arteries, may affect vascular homeostasis. Hypothesis: Obesity and/or coronary artery disease (CAD) are associated with alterations in epicardial adipokines.
Methods: Fasting blood samples and epicardial and subcutaneous fat samples were collected from Caucasian, non-diabetic patients undergoing CABG (CAD group, n=29) or valve replacement (control group, n=17). Adipokine levels were determined in serum and supernatant of adipose tissue organ cultures (0.1 g/ml of media for 24h at 37 °C/5% CO2) by 2-site ELISAs.
Results: Epicardial fat secreted significantly higher amounts of leptin (551 vs 126 pg/g/h), adiponectin (52.2 vs 30.5 ng/g/h) and interleukin-6 (2.22 vs 0.54 ng/g/h) compared to thoracic subcutaneous tissue, all p < 0.001. Epicardial adiponectin release was suppressed in the presence of obesity and CAD (figure⇓). In a multivariate model with sex, age, CAD status and BMI as independent variables, BMI was the only independently significant predictor of epicardial adiponectin (p = 0.01). No additive effect of obesity and CAD was noted. Epicardial adiponectin also correlated with HDL-cholesterol (r = 0.36, p = 0.03) and triglycerides (r = −0.356, p = 0.03). Subcutaneous and systemic adiponectin followed similar trends. Epicardial leptin and interleukin-6 were unrelated to obesity and CAD.
Conclusion: Release of adiponectin, an anti-inflammatory mediator, by epicardial fat is closely related to obesity and CAD. The consequences of this to the neighbouring myocardium and coronary arteries deserve further investigation.