Serum levels of osteocalcin in relation to glucose metabolism and carotid atherosclerosis in Chinese middle-aged and elderly male adults: the Shanghai Changfeng Study.

BACKGROUND

The role of osteocalcin (OCN) in atherogenesis is unclear. We investigated the association between OCN and carotid atherosclerosis in Chinese middle-aged and elderly male adults and further determined whether OCN is independently associated with the carotid atherosclerosis in euglycemic subgroup.

METHODS

A total of 1077 male participants (mean age, 61.3 years) were enrolled from the Changfeng Study. A total of 638 subjects with normal glucose tolerance (NGT) were included in the subgroup analysis. A standard interview, anthropometric measurements and laboratory analyses were performed for each participant. Bilateral carotid intima-media thicknesses (CIMTs) were measured using ultrasonography, and the presence of carotid plaques was assessed. The circulating OCN was measured using electrochemiluminescence immunoassay.

RESULTS

OCN was 18.5 ± 7.5 ng/ml in this male population. Both impaired glucose regulation (IGR) and new diagnosed diabetes (NDD) groups had significantly lower OCN levels compared with the NGT group (17.7 ± 0.4 ng/ml, and 17.4 ± 0.6 ng/ml vs 19.2 ± 0.3 ng/ml, respectively). Multivariate linear stepwise regression analysis demonstrated that triglyceride (TG) (standardized β=-0.065, p=0.042) and fasting blood glucose (FBG) (standardized β=-0.063, p=0.034) were independently and inversely associated with serum OCN. In the NGT subgroup analysis, compared with subjects with OCN in the first quartile, subjects with OCN in the fourth quartile had decreased prevalence of carotid plaque. After adjusting for conventional CVD risk factors, male participants with OCN in the fourth quartile had a 0.57-fold decreased risk of carotid plaques relative to those in the lowest quartile.

CONCLUSION

These results suggest that OCN is independently associated with carotid atherosclerosis in male individuals with NGT and that OCN may be implicated in not only glucose metabolism but also atherosclerosis.