Serum osteoprotegerin and osteopontin levels are associated with arterial stiffness and the presence and severity of coronary artery disease

Background: Osteopontin (OPN) and osteoprotegerin (OPG) have recently emerged as key factors in both vascular remodeling and development of atherosclerosis. Arterial stiffness has an independent predictive value for cardiovascular events. We evaluate the relationship between OPG, OPN serum levels and vascular function in coronary artery disease (CAD) patients. Methods: The study population was consisted of 409 subjects (280 with CAD and 129 without CAD). Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. OPG and OPN levels were measured, as markers of vascular remodeling and calcification, by ELISA. Gensini score was used to evaluate the extent of CAD. Results: CAD patients, compared to those without CAD, had higher OPG (3.91 +/- 1.87 pmol/l vs. 2.88 +/- 1.32 pmol/l, p<0.001) and logOPN levels (1.81 +/- 0.18 ng/ml vs. 1.71 +/- 0.24 ng/ml, p<0.001) and impaired PWV (8.94 +/- 2.21 m/s vs. 8.28 +/- 1.91 m/s, p=0.006). Furthermore, PWV was associated with serum OPG levels (r=0.19, p<0.001) and with serum logOPN levels (r=0.10, p=0.049). Multivariate linear regression analysis revealed that increased OPG (p=0.013) and logOPN (p=0.006) levels are associated with 3-vessel CAD and Gensini score (p=0.04 for OPG and p=0.09 for OPN), independently of other known cardiovascular risk factors. Conclusion: The present study revealed that serum OPG and OPN levels are positively associated with arterial stiffness, and with the extent of CAD. These preliminary results suggest that OPG and OPN levels are significantly correlated with vascular function contributing to the pathogenesis of atherosclerosis in CAD. Further studies are needed to explore the mechanisms of action of OPG and OPN in CAD. (C) 2012 Elsevier Ireland Ltd. All rights reserved.