The Coronary Artery Risk Development in Young Adults (CARDIA) Study is focused on understanding what factors within the environment and individual trigger, promote and influence the development of cardiovascular disease (CVD) in black and white men and women living in the United States. The amount of calcified coronary plaque and the change in calcified plaque burden over five years will provide insight and opportunities for answering the basic design question of CARDIA 'Why do some individuals develop clinical CVD and others do not' through better understanding of the preclinical stages of atherosclerosis. Although calcified coronary plaque as measured by cardiac computed tomography (CT) is but one expression of a multifaceted pathologic process, it provides definitive evidence of the presence and extent of the disease in the blood vessels where plaque rupture occurs and the result is often myocardial infarction and CVD death.The CARDIA baseline exam 1985-86 created a study cohort of 5,115 men and women aged 18-35 in four communities across the United States with equal representation of black and white ethnic groups and gender. The baseline examination consisted of questionnaires on sociodemographic characteristics, health behaviors, and psychological factors; an exercise treadmill test; resting electrocardiography; a diet history assessment; anthropometry; pulmonary function testing; and resting blood pressure. Fasting blood measurements included total cholesterol and its subfractions, insulin, glucose, liver enzymes and other serum chemistry measurements, and hematology. A total of 6 exam cycles have been completed to date, the most recent being the year 15 exam completed in 2001. Retention of the surviving cohort was 90, 86, 81, 79, and 74 percent at each of the respective follow-up examinations. In these exams traditional measures of CVD risk have been measured using the same methods to further our understanding of age and secular trends on these factors. Additional tests and instruments have been used to further enhance our understanding of CVD in young adults and are detailed in the year 15 protocol publicly available at the CARDIA website www.doom.uab.edu/cardia. Measurement of calcified atherosclerotic plaque with cardiac CT was a major component of the year 15 exam and a focus of the primary scientific objectives.
