Both epidemiologic and clinical research in coronary heart disease have increased our awareness that some risk factors for disease such as obesity, hypertension, and hypercholesterolemia may be partially determined by genetic factors or habits which are formed in infancy, childhood, and adolescence. Studies to date also suggest that some of the coronary heart disease risk factors do not change dramatically before the late teenage years and that differences in characteristics by sex or race are most pronounced after this time. However, relatively little work has been done to identify the characteristics of young adult life which may be precursors to or coincident with the increase in risk factors prior to middle age. While major increases in certain risk factors occur in young adulthood in conjunction with significant changes in life style, the interrelationships among these risk factors and changes have not been rigorously investigated.

Cross-sectional data, for example, suggest that weight gain is pronounced during the late teens through age 30, particularly in males, and that a linear relationship exists between weight and lipoprotein fractions at these ages. The reasons for and consequences of this increase in adiposity need further investigation. The interaction of life events, behavior, and changes in physical activity and dietary intake that may influence weight gain and lipoprotein levels should be determined, as well as the importance of weight gain in relationship to risk factor changes during this age span.

Investigators have examined the consistency of blood pressure levels in children to determine whether "tracking" occurs into the teenage years. The results of these studies have raised other interesting and important questions. Is there evidence for "tracking" of other coronary risk factors? Does "tracking" persist into young adult life, a time during which dramatic changes in life style are often taking place? The study will contribute to our understanding of the development of atherosclerosis and will help to determine an optimal strategy for prevention before individual life style patterns become well established. The Working Group on Heart Disease Epidemiology in 1978 recommended the study with highest priority. The study was approved by the National Heart, Lung, and Blood Advisory Council in November 1982. The Request for Proposals was released in December 1982.