1958 Volume 24 Issue 1 Pages 15-33,A2
Although the incidence of deaths resulting from heart disease in Japan is still considerably lower than the of some foreigh countries, a continuous rise in the numer of such deaths is discernible over recent years.
In order to determine the prevalence level and what factors are responsible for this trend, , the need for systematic epidemiological studies is indicated. In carrying out such a project, careful methodological consideration. should be given to the techniques suitable for the survey as well as to the time, place and person preferably to be selected for studies.
The results, using death statistics, X-ray and electrocardiogramme as the indices of the studies, reported as follows:
1. Age: all three indices indicate that as age increases, the prevalence of heart disease increases proportionally.
2. Sex: death statistics and E.C.G. show that a higher percentage of men suffer from heart discase, while X-ray reveal that the percentage of hypertrophy is higher in female than in male especially in rural district.
3. Urban & rural relations: death statistics and X-ray show a higher prevalence of the disease in urban area, while E.C.G. indicate a higher percentage of prevalence in rural district. In the case of abnormal P-wave and arythomia, however, the percentage is found higher in urban area than in rural district.
4. Diet: death statistics and E.C.G. indicate a higher prevalence among overweight-persons, though X-ray indicate a higher rate of hyphertrophy among underweight-persons.
5. Nationality: there is no marked difference in the percentage of abnorma lity in E. C. G. among occidentals living in Japan and Japanese people. It is likely that the similarity in diet ar d in climate plays a greater rule than the difference in nationality.
6. Profession: in the case of those who d: ed with hypertension, a greater numer of fi3herma-n had heart disease than the other profession. This might again indicate this strong influence or diet.
7. Season: the six years average figure of the death rate from heart disease in Nov. & Dec. and also in May & June than in Aug. & Sep. indicating the intimate relationship between the occurrence of death from heart discase and the maladaptation to the changing climate.