Cardiovascular Disease A Brief Review of Epidemiological Studies on Ischemic Heart Disease in Japan

Abstract

The age-adjusted death rate from ischemic heart disease in Japan is the lowest among developed countries and the rates have decreased since 1970. The incidences of myocardial infarction in selected populations ranged between 0.12 and 2.56 per 1,000 for middle-aged males, and between 0.00 and 1.52 per 1,000 for females. The incidences of sudden death within 24 hours were from 0.00 to 1.58 per 1,000 for males and from 0.00 to 0.76 per/1,000 for females. The incidences in Japanese populations appeared to be far below those in Western populations. In the Cox proportional hazard regression model, hypertension and smoking were selected as independent risk factors for myocardial infarction in an agricultural district. It was noteworthy that the level of serum cholesterol was not associated with development of myocardial infarction in rural areas. No positive relation between dietary fat and serum cholesterol was observed in school children, suggesting that growth, sexual maturation and others might be confounding variables between them. The levels of serum cholesterol for females were more affected by menopause than those of blood pressures and body mass index. Although some polymorphisms in selected candidate genes appeared to be associated with some serum lipids and apolipoproteins, the effect of individual RFLP on the inter-individual variations in serum traits was relatively subtle in comparison with that of lifestyle factors.

Past History of Obesity (Overweight by WHO Criteria) Is Associated With an Increased Risk of Nonfatal Acute Myocardial Infarction-A Case-Control Study in JPN-

“…There are several reports showing that obesity is a CAD risk factor in Japan, 6,7,[13][14][15][16]20 as it is in Western countries; [1][2][3][4][5][6] however, there are some that show obesity is not a risk factor among the Japanese population. 21,22 The failure of obesity as a CAD risk factor in those studies may be partly explained by the low prevalence of obesity among Japanese.…”

Hypertension control and medication increase in primary care

“…10 Coronary artery disease was not related in our study probably because of the much lower prevalence of coronary artery disease in Japan. 22 The results of these studies suggest that the presence of other risk factors in hypertensive patients is not an important factor in whether physicians increase medication for treated patients. Our study showed that younger physicians were more likely to increase medication.…”

Treatment of Hyperlipidemia from Japanese Evidence

“…On the other hand, several epidemiological studies failed to show a positive relationship between serum TC and CHD incidence 29,30) . A 15.5-year rural community-based cohort study in Niigata, which was conducted in 1977, has shown no relationship between serum TC and the occurrence of myocardial infarction 29) .…”

“…A 15.5-year rural community-based cohort study in Niigata, which was conducted in 1977, has shown no relationship between serum TC and the occurrence of myocardial infarction 29) . There is a variation in the serum TC levels between rural and urban areas, and CHD mortality may be higher in the urban population than in the rural population 30,31) .…”