The relation between blood pressure and mortality due to coronary heart disease among men in different parts of the world

Background: Elevated blood pressure is known to be a risk factor for death from coronary heart disease (CHD). However, it is unclear whether the risk of death from CHD in relation to blood pressure varies among populations. Methods: In six populations in different parts of the world, we examined sy stolic and diastolic blood pressures and hypertension in relation to long-t erm mortality from CHD, both with and without adjustment for variability in blood pressure within individual subjects. Blood pressure was measured at base line in 12,031 men (age range, 40 to 59 years) who were free of CHD. D uring 25 years of follow-up, 1291 men died from CHD. Results: At systolic and diastolic blood pressures of about 140 and 85 mm H g, respectively, 25-year rates of mortality from CHD (standardized for age) varied by a factor of more than three among the populations. Rates in the United States and northern Europe were high (approximately 70 deaths per 10 ,000 person-years), but rates in Japan and Mediterranean southern Europe we re low (approximately 20 deaths per 10,000 person-years). However, the rela tive increase in 25-year mortality from CHD for a given increase in blood p ressure was similar among the populations. The overall unadjusted relative risk of death due to CHD was 1.17 (95 percent confidence interval, 1.14 to 1.20) per 10 mm Hg increase in systolic pressure and 1.13 (95 percent confi dence interval, 1.10 to 1.15) per 5 mm Hg increase in diastolic pressure, a nd it was 1.28 for each of these increments after adjustment for within-sub ject variability in blood pressure. Conclusions: Among the six populations we studied, the relative increase in long-term mortality due to CHD for a given increase in blood pressure is s imilar, whereas the absolute risk at the same level of blood pressure varie s substantially. These findings may have implications for antihypertensive therapy in different parts of the world. (N Engl J Med 2000;342:1-8.).