[A 10-year field surveillance in Hinohara Village of Tokyo Prefecture from 1981 to 1990]

We conducted a surveillance to clarify the relationship between risk factors for diseases of adulthood and lifestyle in a Japanese rural community, Hinohara Village, a small village outside of Tokyo. The survey, carried out from 1981 to 1990 among residents aged 40 and over, comprised physical examination and blood chemistry with a questionnaire about dietary intake. Mean systolic blood pressure significantly decreased (p < 0.0001) from 140.9 mmHg in 1981 to 132.3 mmHg in 1990, whereas mean serum total cholesterol, mainly of male examinees, increased (p < 0.0001) from 181.4 mg/dl in 1981 to 191.7 mg/dl in 1990. Dietary salt intake significantly decreased (p < 0.0001) from 14.3 g/day in 1981 to 12.1 g/day in 1990. Adjusted mortality rate per 1,000 residents from cerebrovascular disease in this village decreased from 1.80 in 1981 to 0.50 in 1990. In contrast to its decline, the mortality rates from heart disease, bronchitis/pneumonia and neoplasms were 0.40, 0.35 and 0.55 in 1981 and increased to 1.25, 1.10 and 0.64 in 1990. The prevailing practice of maintaining a low-salt diet might cause the decrease of systolic blood pressure, which in turn was thought to decrease the mortality rate from cerebrovascular diseases. Although our previous study before 1981 suggested that total cholesterol was one of the preventive factors against cerebrovascular disease, in the present study a preventive effect of cholesterol was not substantiated. In contrast, cholesterol is a possible risk factor for ischemic heart disease. Thus, a changing pattern of risk factors of diseases of adulthood was observed in this village.