抄録
The incidence and time-related changes in cardiovascular diseases (intracerebral hemorrhage, cerebral infarction, myocardial infarction) were prospectively studied in the two study-populations which were recruited from Hisayama residents, aged 40 or over, in 1961 (first cohort) and in 1973-74 (second cohort), respectively. Cases which had developed into cardiovascular diseases were clinically or pathologically ascertained. The prevalence of hypertension and its manifestation on electrocardiogram decreased in the second cohort, while subjects with hypercholesterolemia or obesity increased.
The average annual incidence of intracerebral hemorrhage was 3.1/1, 000, and that of cerebral infarction was 9.0/1, 000 for men of the first cohort during follow-up (1961-70), while 1.2/1, 000 and 5.5/1, 000 for men of the second (1974-83), respectively, the difference being significant. Cerebral infarction for women was also reduced in the second cohort with the average annual incidence of 3.8/1, 000 from 6.1/1, 000 for the first (p<0.05). Intracerebral hemorrhage for men and myocardial infarction for both sexes did not diminish in the recent population. This evidence is ascribable to the drop of the prevalence of hypertension. The mortality figures from intracerebral hemorrhage and cerebral infarction during 24-year follow-up of the Hisayama study, which were based on death certificates, were corrected by pathological diagnosis. Death rates by intracerebral hemorrhage for men steeply declined throughout the period, which was similar to those of the whole Japan.
Mortality from intracerebral hemorrhage for women, however, was much less than that of the whole Japan from the initiation of the study, keeping almost the same level through the studyperiod. Vital statics of Japan revealed that mortality from cerebral infarction slightly increased until early or middle 1970's, and decreased afterwards. Corrected mortality from cerebral infarction by pathological diagnosis for Hisayama residents, however, constantly showed a down-ward trend and this was accelerated since late 1970's. Based on the results obtained from the study, the quality and reliability of death certificate information was discussed.
