Adiponectin levels in carotid plaques from atherosclerotic patients.

Adiponectin is a circulating adipocytokine with important metabolic effects. It reduces the expression of adhesion molecules on endothelial cells and exerts anti-inflammatory effects thereby protecting against atherosclerosis. Adiponectin was previously detected by immunohistochemistry in injured rat carotid artery and by ELISA in human coronary plaques. We measured adiponectin levels by ELISA in 52 human carotid plaques (American Heart Association [AHA] type V-VIII), in their respective adjacent regions (AHA type II-IV) and in 8 fetal carotids (healthy controls). Adiponectin levels were higher in atherosclerotic lesions than in control tissue (see Figure). In addition, adiponectin level was higher in the region adjacent to the plaque (low grade lesion) than in the plaque. Adiponectin levels were correlated in these two tissues (Pearson coefficient 0.330 p=0.017). Because adiponectin is expressed also in endothelial cells, the increased adiponectin levels in atherosclerotic lesions may be due to increased adiponectin expression. Lastly we have set-up a real time PCR method to measure adiponectin mRNA expression in plaques, in their respective adjacent region and in fetal carotids to verify this hypothesis. These studies are now in progress. Bibliography: Karaduman et al. Clin Endocrinol. 2006;64:196-202.