摘要：To relate the morbidity trends with changes in risk factors for stroke and coronary heart disease between the 1960's and the 1980's, the data of disease surveillance and population surveys of risk characteristics in a northeast rural community of Japan (1965 census population 7, 030) are combined. Between 1964 and 1987, the incidence of all stroke declined about 70% for both men and women aged 40-69. A decline in the stroke incidence was also observed for men and women aged 70 and over in the 1980's. There was about a 50% decline in the prevalence of stroke patients and the number of “bed-ridden” patients with severe disability among men and women aged 40 and over between the 1970's and the 1980's. The incidence of coronary heart disease did not change significantly and was lower than that for stroke. There was an over 10 mmHg systolic and 4 mmHg diastolic blood pressure decline for men and women aged 40-69, primarily in the second decade. The blood pressure decline may have been in part due to increased use of antihypertensive medication which was observed from the first decade. However, part of the blood pressure decline may be attributed to changes in related behaviors and environmental factors such as decreased salt intake and the improvement of working conditions, since the substantial decline occurred in the second decade. Between the 1960's and the 1980's, daily average salt intake decreased from 20 g to 14 g for men aged 40-59. Animal fat intake doubled from 4.5% to 9.6%. The most of the increase of fat intake was seen in the first decade due to an increased intake of meat, eggs and dairy products. Mean serum cholesterol increased 22 mg/dl to the 1980's mean level of 179 mg/dl in men aged 40-69, and 29 mg/dl to 192 mg/dl in women age 40-69. The increase of serum cholesterol level paralleled the increased intake of animal fat. A cohort of men and women aged 40-69 were followed from 1963-1966 to 1973 (2, 257 persons) to examine risk factors of stroke. According to multivariate regression analyses, blood pressure levels and end organ effects in the electrocardiogram and fundus photographs were significantly associated with the incidence of cerebral hemorrhage and infarction. Serum total cholesterol was inversely associated with cerebral hemorrhage. Reliable estimates of risk factors for coronary heart disease in this population was not obtained because of the small number of cases. Surveillance and risk factor surveys are continuing in order to clarify trends in cardiovascular diseases in the rural Japanese population in the future.
