Body Weight, Cardiovascular Risk Factors, and Coronary Mortality

Abstract

Background Body weight is closely related to several known cardiovascular risk factors, but it may also have an independent effect on the risk of coronary heart disease (CHD). In this study, we analyzed the association between body mass index (BMI) and smoking, serum cholesterol, and blood pressure at baseline, as well as how BMI and the other risk factors are related to CHD mortality. Methods and Results A total of 16 113 men and women aged 30 to 59 years were examined in eastern Finland in either 1972 or 1977. Serum cholesterol and blood pressure had a positive association and smoking had a negative association with BMI. During the 15-year prospective follow-up, mortality from CHD was positively associated with BMI. The BMI-associated risk ratio of CHD mortality, adjusted for age and study year, estimated from the Cox proportional hazards model was 1.04 (per kg/m²) (P<.001) among men. Inclusion of smoking in the model increased the risk ratio for BMI, whereas inclusion of serum cholesterol and blood pressure decreased it. In the model that included age, study year, and all three major cardiovascular risk factors, the BMI-associated risk ratio was 1.03 (P=.027). Among women, the BMI-associated risk ratio of CHD mortality adjusted for age and study year was 1.05 (P=.023) and the multifactorial adjusted risk ratio was 1.03 (P=.151). Conclusions Obesity is an independent risk factor for CHD mortality among men and also contributes to the risk of CHD among women. Part of the BMI-associated risk of CHD mortality is mediated through other known cardiovascular risk factors. By preventing overweight, a substantial part of CHD mortality may be prevented.