Cardiovascular disease (CVD) and osteoporosis are major causes of morbidity and mortality among elderly people. The two conditions have generally been considered unrelated. However, studies have indicated that arterial calcification is an active, organise d, regulated process similar to bone mineralization. Thus, there may be links between bone metabolism and vascular calcification, but data based on large longitudinal studies are very sparse.
In the Tromsø study, a large population-based study, bone mine ral density (BMD) was measured in 5716 subjects at baseline in 1994/95 and 7 years later. The examination also included carotid ultrasonography and measurements of e.g., weight, blood pressure and non-fasting serum lipids. These data may enable us to exam ine whether subjects with osteoporosis are at risk developing atherosclerosis and visa versa.
The main objective of this population-based study is to describe how osteoporosis and cardiovascular diseases are interrelated.
Thus, we will examine whether subjects with low BMD, and subjects who loose bone rapidly at increased risk of stroke and myocardial infarction and whether the presence and type of carotid artery plaque (an non-invasive measure of generalized atherosclerosis) is related to the risk of future fractures. Furthermore, does the loss of bone minerals differ in subjects with hard carotid artery plaques and subjects with soft or no plaques?
We will also investigate relationships between risk factors for cardiovascular diseases (e.g., blood pressure, lipid profile at baseline (1994/1995), high glycated hemoglobin and microalbuminuria) and BMD and fracture risk within the following 7 years. A related question is whether changes in BMD from baseline to 2001 are related to changes in risk these factors.
The study may identify subjects at increased risk of both diseases. Moreover, modifiable risk factors that link the two diseases may be identified.