Abstract-The aim of this study was to determine the magnitude and significance of the associations among coronary artery calcium (CAC) and systolic blood pressure, diastolic blood pressure, pulse pressure, and mean arterial pressure. Women 50 to 59 years of age at baseline in the Women's Health Initiative clinical trial of conjugated equine estrogen underwent computed tomography scanning of the chest after the end of the trial. Blood pressures were measured twice with the participant in the seated position using a conventional mercury sphygmomanometer. The study included 1064 women with a mean age of 55.1 (2.8) years. The prevalence of a CAC score Ͼ0, Ն10, and Ͼ100 was 47%, 39%, and 19%, respectively. There was a linear association between the log-odds of any CAC and systolic blood pressure, whereas there was a curvilinear and inverse association with diastolic blood pressure. For any value of diastolic blood pressure, the probability of CAC increased with higher levels of systolic blood pressure, whereas for any given value of systolic blood pressure, the probability of any CAC decreased with higher levels of diastolic blood pressure. Also, a pulse pressure Ն55 mm Hg was associated with a higher odds (1.95; 95% CI, 1.24 to 3.06) for having any CAC, whereas individuals with isolated systolic hypertension had a 73% higher odds for CAC Ͼ0 (95% CI, 1.03 to 2.90; Pϭ0.04).In postmenopausal women, higher levels of pulse pressure and systolic blood pressure were strong determinants of CAC, whereas diastolic blood pressure was inversely related. Key Words: calcium Ⅲ coronary Ⅲ pulse pressure Ⅲ women Ⅲ coronary artery disease Ⅲ atherosclerosis Ⅲ postmenopausal I n a regulated process similar to skeletal bone formation, 1 calcium is deposited in atherosclerotic plaques. 2 With the advent of computed tomography (CT), these calcified atheromatous plaques can be detected throughout the vasculature. 3 Moreover, because of decreases in the acquisition time required to obtain the images, these calcium deposits can also be visualized in the coronary arteries. 4 The extent of calcified coronary atherosclerotic plaques is highly correlated with both the total atheromatous plaque burden 5 and the percentage of stenosis 6 in that vascular bed as well as being a strong and independent predictor of incident coronary heart disease (CHD) events in both men and women. 7,8 Coronary artery calcium (CAC) is increasingly advocated as a component of individual cardiovascular disease (CVD) risk stratification procedures. 9 Accordingly, knowledge of the differential associations between risk factors for CAC and CHD is clinically relevant. Previous studies have found significant associations among several CVD risk factors (age, male sex, cigarette smoking, diabetes, and family history) of CHD and the presence and extent of CAC, 10,11 whereas the associations for different cholesterol fractions are more modest. 12 Notably, hypertension has been shown to be strongly associated with the presence of CAC. 13 However, previous reports have not typical...