Relationship between serum osteocalcin levels and carotid intima-media thickness in Chinese postmenopausal women

Objective: Serum osteocalcin has been shown to be closely related to metabolic risk factors. Therefore, the aim of our study was to evaluate the association between serum osteocalcin levels and subclinical atherosclerosis in Chinese postmenopausal women. Methods: A total of 1,319 postmenopausal women (age range, 41-78 y) without any history of cardiovascular disease or carotid plaque were analyzed. Electrochemiluminescence immunoassay was used to measure total serum osteocalcin levels. B-mode ultrasound measurement of carotid intima-media thickness (C-IMT) was used to evaluate subclinical atherosclerosis. Participants within the upper quartile of C-IMT measurements (>= 0.65 mm) were classified as having increased C-IMT in the present study. C-IMT association with metabolic parameters was assessed by Spearman correlation analysis, whereas that with serum osteocalcin was assessed by multiple stepwise regression adjusted for potential confounders. Results: The overall median (interquartile range) level of osteocalcin was 20.51 (16.71-24.98) ng/mL, and that of C-IMT was 0.60 (0.55-0.65) mm. Four hundred sixteen (31.5%) participants had increased C-IMT. Participants with increased C-IMT had significantly lower serum osteocalcin levels than those who had C-IMT lower than 0.65 mm (19.77 [16.17-24.52] vs 20.84 [16.92-25.39] ng/mL, P = 0.01). Serum osteocalcin level was significantly and negatively correlated with C-IMT (r = -0.107, P < 0.01) and was identified as an independent factor that significantly influenced C-IMT (standardized beta = -0.117, P < 0.01). Conclusions: Serum osteocalcin level is negatively associated with subclinical atherosclerosis in Chinese postmenopausal women.