Context: For women, impact of cardiovascular risk factors measured in young adulthood, particularly favorable (low-risk) profile, on mortality has been difficult to assess due to low short-term death rates.
Objective: To assess the relationship of baseline coronary risk factor status to mortality from coronary heart disease (CHD), cardiovascular diseases (CVDs), and all causes in young women.
Design: Prospective cohort study.
Setting and participants: A total of 7302 women aged 18 to 39 years without prior CHD or major electrocardiographic abnormalities screened between 1967 and 1973 for the Chicago Heart Association Detection Project in Industry. Risk groups were defined using national guidelines for values of systolic and diastolic blood pressure, serum cholesterol level, body mass index, presence of diabetes, and smoking status. Participants were divided into 4 groups: low risk, 0 risk factors high but 1 or more unfavorable, 1 only risk factor high, and 2 or more risk factors high.
Main outcome measures: All-cause mortality, CHD mortality, and CVD mortality; hazard ratio of outcome measures comparing low-risk group with other groups.
Results: Only 20% met low-risk criteria; 59% had high levels of 1 or more risk factors. During an average follow-up of 31 years, there were 47 CHD deaths, 94 CVD deaths, and 469 deaths from all causes. The age-adjusted CVD death rate per 10,000 person-years was lowest for low-risk women and increased with the number of risk factors, ie, 1.5, 1.7, 5.0, and 9.1 for low-risk; 0, 1, and 2 or more risk factors high, respectively. Multivariate-adjusted CVD mortality hazard ratio for low-risk women was 0.19 (95% confidence interval, 0.08-0.45) compared with women with 2 or more risk factors high. Similar patterns were observed for CHD and all-cause mortality and for both blacks and whites.
Conclusion: For women with favorable levels for all 5 major risk factors at younger ages, CHD and CVD are rare; long-term and all-cause mortality are much lower compared with others.