Association of bone metabolism markers with coronary atherosclerosis and coronary artery disease in postmenopausal women

This study aimed to evaluate the association of bone metabolism markers with coronary atherosclerosis and coronary artery disease (CAD) in postmenopausal women. Based on the findings of coronary angiography, 111 women with CAD and 116 women without CAD were recruited. Serum calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), osteocalcin, N-terminal propeptide of type I procollagen (P1NP) and C-terminal cross-linked telopeptide of type I collagen (CTX) were measured. The Gensini score was used to assess the severity of coronary atherosclerosis. Compared with women with serum calcium <= 2.29 mmol/L, women with serum calcium > 2.29 mmol/L had a 2.63-fold increased risk of CAD after adjusting for multiple cardiovascular risks, PTH and 25OHD [odds ratio (OR) = 2.91, 95% confidence interval (CI) 1.35-6.28]. In the fully adjusted model plus PTH and 25OHD, the risk of CAD increased 1.87-fold with every 1-SD increment of serum calcium (OR = 1.87, 95% CI 1.21-2.88). To further analyze the potential strong confounding effect of albumin, the absolute levels of calcium were replaced by their albumin-corrected values in the regression model. Compared with women with albumin-corrected calcium <= 2.27 mmol/L, women with albumin-corrected calcium > 2.27 mmol/L had a 2.36-fold increased risk of CAD in the fully adjusted model plus PTH and 25OHD (OR = 2.36, 95% CI 1.13-4.92). The risk of coronary atherosclerosis as defined by Gensini score > 0 increased 1.73-fold with every 1-SD increment of serum calcium in the fully adjusted model plus PTH and 25OHD (OR = 1.73, 95% CI 1.09-2.73). However, albumin-corrected calcium was not associated with coronary atherosclerosis either as a categorical variable or as a continuous variable in all models. No significant association of PTH, 25OHD, osteocalcin, CTX and P1NP with CAD or coronary atherosclerosis was found in this study. Higher serum calcium levels were independently associated with CAD in postmenopausal women.