Carotid intima-media thickness and bone turnover: the role of C-terminal telopeptide of type I collagen.

Osteoporosis and vascular disease are commonly found together in elderly people. Several common mechanisms and risk factors have been suggested to contribute to the development of osteoporosis and atherosclerosis. The present cross-sectional study was performed to determine whether the degree of bone turnover is correlated to carotid intima-media thickness (CCA-IMT), as a marker of subclinical atherosclerosis. We selected 50 outpatients (mean age 71.7 +/- 12.3), underwent to eco-Doppler evaluation of extracranial carotid tract, without history of calcium and/or vitamin D supplementation, or antireabsorptive therapy. CCA-IMT was measured by high-resolution B-mode ultrasonography. Bone turnover was evaluated by analysing serum levels of C-terminal telopeptide of type I collagen (sCTX), and bone-specific alkaline phosphatase. We also evaluated the vitamin D status by determination of the serum concentration of 25-hydroxyvitamin D [25(OH)D]. We found a prevalence of hypovitaminosis D [serum 25(OH)D levels <30 ng/mL, mean value 10.7 +/- 5.8] of 91.8%, and an increased bone resorption, with mean sCTX levels higher than reference values (mean 1.18 +/- 0.57 ng/mL). A significant positive correlation was found between CCA-IMT and age (r = 0.480, P = 0.001), erythrocyte sedimentation rate (ESR: r = 0.438, P = 0.001), high-sensitivity C-Reactive Protein (HsCRP: r = 0.482, P = 0.011), serum creatinine (r = 0.305, P = 0.031), and sCTX (r = 0.389, P = 0.006). In a multivariate linear regression, CCA-IMT was independently predicted by age (beta = 0.34, P = 0.001), ESR (beta = 0.37, P = 0.005), and sCTX (beta = 0.32, P = 0.006). The preliminary results of our study seem to indicate that after adjustment for established cardiovascular risk factors, sCTX independently predict an increased CCA-IMT in the elderly population.