Decreased ovarian function and premenopausal obesity are likely the primary determinants of early coronary atherosclerosis as measured by calcification on EBCT. Aortic calcification occurs earlier than coronary calcification, may predict coronary calcification, and is expected to be the best marker of risk associated with traditional factors in these younger women. Preliminary data indicate that changes in coronary and aortic calcification can be observed over short periods of time in these women. A period of diminishing estrogen levels is the optimum time to observe changes in endothelial function which likely precede measurable atherosclerosis and thus may be the earliest markers for disease potential. Vascular stiffness, a marker for the biologic aging of the vascular system, is highly correlated with measures of insulin sensitivity which is altered in women at mid-life in conjunction with increases in central adiposity. Racial differences in disease prevalence and the relative importance of certain risk factors are likely.