Low total osteocalcin levels are associated with the risk of cardiovascular events among women with hyperglycaemia: a 7.6-year prospective study.

Purpose: To investigate the association between circulating osteocalcin and incident cardiovascular diseases in a community-based cohort, and further assess whether the association differs by different glycemic stages. Methods: This cohort study included 1428 participants (626 men and 802 women) aged 50–80 years, without baseline cardiovascular diseases, and with osteocalcin data available. Circulating total osteocalcin levels were measured by electrochemiluminescence immunoassay. Multivariate Cox proportional hazards models were used to assess the relationship between osteocalcin levels and different glycemic stages with cardiovascular events. Results: At baseline, 437 participants were normoglycaemia and 991 participants were hyperglycaemia. Median circulating osteocalcin levels were 16.43 (13.34–20.19) and 21.66 (17.95–26.11) ng/mL in men and women, respectively. During a mean follow-up of 7.6 years, 144 cases of cardiovascular diseases occurred (10.1%). The risk of incident cardiovascular diseases linearly increased with a decrease in baseline osteocalcin quartiles (quartile 1 versus quartile 4: hazard ratio 2.44, 95% confidence interval 1.07–5.55) in women, while not in men (P_{interaction on sex} = 0.028). Subgroup analyses showed that the association was more predominant in participants with baseline hyperglycaemia. Besides, the joint effect of baseline decreased osteocalcin levels and hyperglycaemia resulted in higher risks of future cardiovascular diseases. Conclusions: Low baseline osteocalcin levels were associated with high risks of cardiovascular diseases in middle-aged and elderly women, which were more predominant among those with baseline hyperglycaemia. [ABSTRACT FROM AUTHOR]