Cardiovascular disease and osteoporosis.

Cardiovascular disease (CVD) and osteoporosis (OP) are public health problems with numerous epidemiological links and important economic consequences. Recent studies have demonstrated that CVD and cardiovascular mortality are associated with reduced bone mineral density (BMD) and bone fractures. These two conditions may be sustained by similar or common pathophysiological mechanisms and risk factors. There are several matrix proteins, such as type 1 collagen, proteoglycan, osteopontin, and osteonectin, which are found in bone and vascular matrix components. Matrix proteins play an important role both in bone formation and in the development of atherosclerosis. Estrogens also play a role in both CVD and OP through their effects on cytokines, such as IL-1, IL-6 and TNF-alpha and osteoprotegerin (OPG). The lack of estrogens induces an increase in these cytokines and a decrease in OPG, both implicated in the mechanisms of bone loss and atherogenesis. An additional link between CVD and OP seems to be related to the action of some drugs, such as bisphosphonates, statins and raloxifene. Several studies suggest that the mechanism of action of these drugs at cellular level may not be mutually exclusive, acting either in bone or in atherosclerotic plaque. However, further studies are necessary to define the relationship between CVD and OP more specifically and to understand the complex interaction of similar or common risk factors and genetic or molecular determinants.