Background. New assumption concerning association of osteocalcin and Vascular calcification has emerged in reaction to observations that the mechanism of vascular calcification resembles that of bone mineralization, thus linking bone and the vasculature. However, studies reported contrasting results about the association between osteocalcin and atherosclerosis. This study was designed to evaluate capacity relationships among different forms of circulating osteocalcin and cardiovascular risk markers in male with coronary atherosclerosis. Methods. A cross-sectional study was conducted on 58 male patients, divided into two groups according to the severity of coronary artery disease (CAD), as determined by coronary angiography assessment: Early coronary atherosclerosis (ECA), n=20, patients with mild CAD (<50% stenosis in any major epicardial arteries), and late coronary atherosclerosis (LCA), n=38, patients with severe, multivessel CAD (>50% stenosis in at least one or more major epicardial arteries). The healthy control (HC) group included 26 healthy male subjects. Carboxylated (cOC) and ucOC were measured using ELISA technique. Results. We observed significantly lower ucOC levels in both stages of cardiovascular disease (CVD) (ECA and LCA) compared to the HC group (2.34±2.23 and 2.48±1.60 vs 6.65±1.78 ng/mL, P<0.01). ucOC was inversely correlated with an increasing number of cardiovascular risk factors (CVRFs). Moreover, ucOC levels were markedly reduced in high-fasting plasma glucose (FPG) groups (IFG and T2DM-threshold level), compared to the normal FPG group (NG). cOC levels were higher in the IFG group, compared to the normal FPG group (8.50±4.76 vs 7.13±3.13 ng/mL, p=0.008) possibly predicting such condition

Conclusions. In the present study, patients with coronary atherosclerosis, regardless of the onset of stenosis, showed lower ucOC levels which were inversely correlated with an increasing number of CVRFs. Moreover, ucOC levels were markedly reduced in high-FPG groups. Serum ucOC may be considered as a potential biomarker for coronary atherosclerosis disease and therefore its measurement may help to establish preventive and therapeutic approaches. Moreover, cOC may be associated with a high alert for diabetes at the IFG stage, but not when the disease progresses to diabetes.