1993 年 3 巻 2 号 p. 63-70
In Japan recently there has been a rapid change in living and eating patterns along with accelerated urbanizations in rural communities. This provides an unique opportunity to observe a critical "natural experiment" of change in both risk factors and disease. Data on blood pressures and time trends were obtained in population-based surveys conducted in rural Japan ; the first survey from 1963-66, the second from 1972-75, and the third from 1980-83. This report describes the population trends over 20 years for blood pressure distributions and its related factors. Between the 1960s and the 1970s, the prevalence of a higher blood pressure level declined although no remarkable shift of the blood pressure distribution was observed. However, between the 1970s and the 1980s, there was a significant downward shift of the blood pressure distribution. The decline in blood pressure between the 1960s and 1970s was primarily related to a fall in the prevalence of elevated blood pressure, attributable in turn to the greater use of anti-hypertensive medications and improved blood pressure control. In contrast, the large downward shift in the whole blood pressure destributions between the 1970s and the 1980s was attributable partly to improved hypertension control and apparently also to changes in environmental factors of associated behaviors that affected the whole distribution. The correlation between blood pressure and relative weight index was weak in the 1960s but became stronger in the 1970s and the 1980s. The significant blood pressure trend in a whole population are consistent with the reported decline in stroke incidence in this population. J Epidemiol, 1993; 3 : 63-70.
