Serum osteoprotegerin and carotid intima–media thickness in acute/chronic coronary artery diseases

Osteoprotegerin (OPG) plays a key role in atherosclerosis progression and plaque destabilization. We investigated the relationship between intima–media thickness of the common carotid artery (CCA-IMT; an early marker of atherosclerosis) and OPG levels in patients with acute coronary syndrome (ACS) and chronic coronary artery disease (CAD). We studied 133 consecutive patients, mean age 65 ± 9 years, referred to our department for coronary angiography. They were evaluated for cardiovascular risk factors, OPG levels and CCA-IMT and accordingly divided in two subgroups: ACS and chronic CAD. Except for age, the two groups were similar according to conventional cardiovascular risk factors. The chronic CAD group showed a CCA-IMT lower than the ACS group (0.86 ± 0.15 vs. 0.94 ± 0.22 mm, P = 0.027); there were no differences regarding the extension of coronary atherosclerosis on angiograms. The OPG levels were higher in chronic CAD patients than in ACS patients (5.36 ± 3.06 vs. 3.85 ± 2.96 pmol/l, P = 0.004). Moreover, the CCA-IMT was significantly correlated with the age of the patients (r = 0.5; P < 0.001). OPG values were not related either to age or to the CCA-IMT. At analysis of covariance, when adjusting the groups for age, the comparison of the two groups lost statistical significance for CCA-IMT (P = 0.41), whereas the OPG values remained significant after the correction (P = 0.001). OPG levels are higher in chronic CAD patients. CCA-IMT confirmed its importance in predicting CAD, showing significantly higher values in the patients in the ACS group as compared with those in the chronic CAD group.