Risk factors for coronary heart disease in men 18 to 39 years of age

Background: Few studies have evaluated the long-term predictive capacity of risk factors for death from coronary heart disease in men younger than 40 years of age. Objective: To assess the predictive capacity and discriminatory ability of major coronary risk factors in predicting death from coronary heart disease in young men. Design: Prospective cohort study with 20 years of follow-up. Setting: 84 companies in the Chicago area that participated in the Chicago Heart Association Detection Project in Industry (1967-1973). Participants: 11 016 men 18 to 39 years of age (mean age, 29.7 years) at baseline were the primary focus of this report; 8955 men 40 to 59 years of age at baseline served as a reference group. Measurements: The main end point was death from coronary heart disease. Results: All major risk factors - age, serum cholesterol level, systolic blood pressure, and cigarette smoking - were significantly associated with death from coronary heart disease over 20 years in young men. Relative risks for the major risk factors were of generally similar magnitude in young and middle-aged men. Receiver-operating characteristic curves for the best predictive model yielded an area under the curve of 0.82, indicating that standard risk factors were highly predictive of long-term outcome in young men. Conclusions: Major coronary disease risk factors, many of which are modifiable, are strong contributors to prediction of future risk, even in young men. These data may help in formulating appropriate strategies to identify young men at heightened risk for death from coronary heart disease in later adulthood.