[Epidemiological survey of cerebro-cardiovascular diseases at Iwamizawa in Hokkaido (author's transl)].
Since 1969, we have investigated epidemiological studies of cerebro-cardiovascular diseases in the suburbs of Iwamizawa city in Hokkaido, the northernmost island of Japan. Cross-sectional surveys of 1,092 persons, equivalent to 90.3% of inhabitants over 40 years of age, revealed that the prevalence of hypertension amounted to 34%, and that the prevalence of abnormal ECG, CTR, fundi, albuminuria, glucosuria and overweight in the hypertensive group were significantly higher than in the normotensive group. After a 5-year cohort follow-up study concerning the incidence of strokes and heart attacks, age was found to be the highest risk factor in both incidents and hypertension was the second highest in cerebrovascular accidents, but not so high in heart attacks. In addition, we measured plasma renin activity (PRA) as a risk factor. On the basis of our observations, it is evident that the casual PRA of the rural Japanese population in Hokkaido, who usually excrete sodium more than 200 mEq per day, is valuable for our study. PRA was inversely proportional to systolic blood pressure in the normotensives and total group, but no correlation was found in the hypertensives alone. Observing 13 renin-determined accidents (8 strokes & 5 heart attacks) prospectively, incidence of strokes and heart attacks occurred more frequently in the high- and low-renin subgroups than in the normal-renin subgroup. Based on multivariate analysis, the following conclusion was drawn: systolic pressure, high renin, diastolic pressure and low renin, in this sequence, contribute largely toward the discrimination of cerebro-cardiovascular accident from no cerebro-cardiovascular accident. Thus it was suggested that the casual PRA was useful to predict the occurrence of vascular complications, in addition to the existence of hypertension. It has been said that the mortality rate of CVA in Hokkaido is less than the average of the rest of northern parts in Japan. By the vital statistics and our survey, it was clear that seasonal variation of the death rate from CVA and heart attack, which increases in the winter season, is weaker in Hokkaido than in Honshu. It is of interest to speculate that it is due to better-equipped heating in houses in Hokkaido than in other northern parts of Honshu.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002561:Cerebrovascular Disorders / Q000378:metabolism / Q000401:mortality*; D002648:Child; D003081:Cold Climate; D003327:Coronary Disease / Q000378:metabolism / Q000401:mortality*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine; D014798:Vital Statistics
D012964:Sodium; D012083:Renin