The specific goals are to determine if bone marrow density is correlated with coronary artery and aortic calcification (CAC) and, if so, to determine the contribution of common genes or shared environments to this association in families. The investigators will next assess genetic heritability and non-genetic contributions to variability in vascular calcification determinants of CAC in these families. They will assess the individual and joint contributions of lipid oxidation to bone marrow density and vascular calcification. Using the extensive genotyping that will be available, they will perform a genome wide scan of coronary artery and aortic calcification. These results will complement the similar analyses obtained on the bone-related phenotypes. Finally, they will determine if chromosomal regions linked to variation in bone marrow density are also linked to variation in vascular calcification or to another possible joint determinant such as CAC (or to lipid oxidation).