The association between serum osteocalcin levels and metabolic syndrome in Koreans

The association between serum osteocalcin levels and metabolic syndrome (MS) in Korean individuals was investigated. Serum osteocalcin levels are significantly lower in subjects with MS than in those without the disease, regardless of glucose metabolism. Introduction Osteocalcin was recently shown to affect energy metabolism. In the present study, we investigated the possible association between serum osteocalcin concentrations and MS. Methods A cross-sectional community-based survey was conducted. Serum osteocalcin, type 1 collagen C-telopeptide (CTX) and total alkaline phosphatase (ALP) concentrations were determined in 567 subjects. MS was defined according to NCEP-ATP III criteria. Results Serum osteocalcin concentrations were significantly lower in subjects with MS than those without MS in postmenopausal women (18.923 +/- 7.685 vs 22.513 +/- 7.344 ng/ml, P<0.001) and marginally lower in subjects with MS than those without MS in men (14.550 +/- 5.090 vs 16.125 +/- 4.749 ng/ml, P=0.086) after adjustment for age and BMI. Further controlling with CTX or ALP did not affect this association in postmenopausal women; however, controlling with osteocalcin abolished the association between CTX and MS. Significant differences in serum osteocalcin levels by MS status were noted in subjects with normal glucose tolerance as well as those with abnormal glucose tolerance (P=0.032 and P<0.001, respectively). Compared with subjects with the highest quartile of osteocalcin, those in the lower quartile groups (Q1-Q3) had significantly increased risks of MS (ORs=5.18, CIs=1.15-23.42) in men. In postmenopausal women, the ORs for MS were significantly higher in the lowest quartile than in the highest quartile (ORs=5.25, CIs=2.42-11.36). Conclusions These findings suggest that osteocalcin is associated with MS, independently of glucose metabolism.