The atherosclerotic process begins in childhood and advances through adult life when occlusive vascular disease results in coronary heart disease, stroke and peripheral vascular disease. Although risk factors have been established in adult populations, risk factors when measured in childhood have not been directly related to morbidity and mortality from occlusive atherosclerotic disease. The ultrasonographic measurement of carotid artery intimal-medial thickness (IMT) in adults is related not only to the risk for stroke but also to the severity of atherosclerotic disease in the coronary arteries. In 1970, a population of school age children and adolescents was first examined in Muscatine, Iowa, and since then has been followed to examine the predictive value of childhood risk factor levels for cardiovascular disease. See also Study 906 (Muscatine Heart Study).