[Trends, risk factors, and prevention of ischemic heart disease in Japan]

The mortality from ischemic heart disease has increased steadily in most industrialized countries from the 19th century up to 1970. In some developed countries, such as the U.S.A. and Australia, it started to decrease in the nineteen seventies and accelerated recently. However, it has increased in some East European countries, such as Rumania, Poland and Hungary. The mortality had been extraordinarily low and the age standardized rate declined since the nineteen seventies in our country as in the U.S.A. These finding strongly suggests the possibility of prevention of ischemic heart disease worldwide. Among the risk factors, hypertension has gradually decreased due to treatment and lower intake salt in Japan. However, the compliance of antihypertensive treatment could be improved and the average intake of salt further decreased. The frequency of hypercholesterolemia was quite low for many years, but increased recently in Japan. However, the national average level of serum cholesterol is probably close to 200 mg/dl, and the new cholesterol level data will be revealed by the national survey in 1990. The world-famous high figure of smoking among Japanese men has been declining for these 20 years down to 61.2% in 1988, along with an exceptionally low rate for women in industrialized countries. The average figure of body weight by stature was in line with the desirable body weight for Japanese and the average intake of lipids has leveled off recently according to the National Nutrition Survey. After all it can be concluded that incidence of ischemic heart disease could be reduced further, even in Japan.