Strategy for the Prevention of Cardiovascular Diseases in East Asian Countries Based on the Experience of Japan

Cardiovascular disease is a major cause of morbidity and mortality in East Asian countries as well as in western countries. However, it is a characteristic specific to East Asia that stroke is more prevalent than coronary heart disease (CHD). In 1965, Japan had the highest stroke mortality rate in the world, but the rate has since declined substantially: the age-adjusted stroke mortality rate fell by around 80% from 1965 to 1990. Risk factors for stroke in Asian countries include hypertension, smoking and diabetes. Hypercholesterolaemia is not a strong risk factor for stroke or even for ischemic stroke, but it is a risk factor for CHD in Asian countries as well as in western counties. Therefore, the control of blood pressure and diabetes and cessation of smoking are crucial for preventing stroke and disability in the elderly. During the last four decades in Japan, the blood pressure level has fallen among both sexes and in all age groups: the systolic blood pressure (SBP) of men 60–69 years of age fell by 16mmHg from 1965 to 1990. This is estimated to have reduced stroke mortality by around 50% because, based on Japanese cohort studies, an SBP reduction of 1mmHg may lead to a 3% reduction in the incidence of stroke. Similarly, a 1% reduction in the incidence of smoking may lead to a 1.3% reduction in the incidence of stroke, so the 20% reduction of the smoking rate during this period is estimated to have led to a 26% reduction in the incidence of stroke. In addition, the significant reduction in salt consumption over this time period, by at least 10–15g per day, has substantially reduced blood pressure among the Japanese population. Lowering blood pressure by reducing salt intake, promoting smoking cessation and preventing diabetes are therefore key strategies for preventing stroke and disability in the elderly.