Background and objective: Recent information has highlightened the impact of HA metabolism alterations in vascular permeability through its actions on endothelial glycocalyx and the importance of HA-cell interactions in cell behavior of arterial endothelial and smooth muscle cells. Therefore hyaluronan is thought to involve in pathophysiology of atherosclerosis. The aim of this study is to investigate the association of plasma hyaluronidase activity with atherosclerosis in non-diabetic patients with stable coronary artery disease. Methods: In the present study we used plasma hyaluronidase measurement as an indicator of hyaluronan metabolism and activity. A total of 162 subjects undergoing to coronary angiography were divided into two groups according to presence or absence of coronary artery disease, and their serum hyaluronidase activity were measured. Results: Serum hyaluronidase activities were 3797±670.62 mU/L and 2838±417.67 mU/L for patients with CAD (n:109) and control patients without CAD (n:53), respectively. Serum hyaluronidase activity in patients with coronary artery disease (CAD) were significantly higher than control subjects without CAD (p<0.001). Conclusion: In the present study hyaluronidase activity was found to be associated with coronary artery disease reflecting the role of hyaluronan in atherosclerosis. We believe that the demonstration of relationship between serum hyaluronidase activity and atherosclerosis represents a remarkable finding highlighting the potential role of hyaluronan in pathophysiology of atherosclerosis (Tab. 2, Fig. 3, Ref. 28). Full Text (Free, PDF) www.bmj.sk.