The seven countries study: 2,289 deaths in 15 years

Area of Science:

• Epidemiology
• Cardiovascular Disease Research
• Public Health

Background:

• Cardiovascular disease (CVD) poses a significant global health challenge, with varying mortality rates observed across different geographic regions.
• Understanding the interplay of lifestyle and physiological factors contributing to CVD mortality is crucial for effective public health interventions.

Purpose of the Study:

• To investigate the cohort and individual risk factors associated with all-causes and coronary heart disease (CHD) mortality across diverse international populations.
• To examine the predictive power of baseline characteristics, including serum cholesterol, blood pressure, smoking, body weight, and physical activity, on mortality outcomes.

Main Methods:

• Analysis of data from 15 cohorts comprising 11,579 men aged 40-59 without pre-existing cardiovascular disease, followed for 15 years.
• Statistical modeling to assess the influence of cohort-level and individual-level risk factors on all-causes and CHD mortality rates across seven countries in four regions.

Main Results:

• Cohort differences in all-causes mortality were primarily explained by coronary mortality variations, with mean blood pressure being a significant explanatory factor.
• Serum cholesterol and blood pressure accounted for three-quarters of the variance in coronary death rates between cohorts.
• Individually, age, serum cholesterol, blood pressure, and smoking were significant predictors of coronary death in most regions, while relative weight was not consistently significant.
• Age, blood pressure, and smoking were significant predictors of all-causes death across all regions except Japan.

Conclusions:

• Blood pressure and serum cholesterol are critical determinants of coronary heart disease mortality at both cohort and individual levels.
• While lifestyle factors like smoking are important, regional variations in mortality highlight the complex interplay of genetics, environment, and socioeconomic factors.
• Public health strategies targeting blood pressure and cholesterol management are essential for reducing cardiovascular disease burden globally.