The present study, a follow-up study for 669 aged examinees of a health check performed in July 1983 in a rural area in Fukushima Prefecture, was conducted to clarify the relationship between relative weight and mortality among aged individuals living in a Japanese rural area. Using the standard body weights calculated from Japanese mean body weights by sex, age class (60-69 and 70 or more) and height cited from the data of the Ministry of Health and Welfare from 1966, mortalities during the five year follow-up were compared among four groups different in relative weight at baseline.
The results are as follows.
1) The mortalities in the group of ‘Relative weight≤-10%’, the leanest group among the four groups, were highest in both sexes, 52.8per 1000 person-years for males and 33.2per 1000 person-years for females. On the other hand, those in the group of ‘+10%≤Relative weight<+20%’ were lowest in both sexes, 23.1per 1000 person-years for males and 7.0per 1000 person-years for females. In females, the difference in the mortality between these two groups was statistically significant at the 0.05 level, provided age structures in both groups were taken into consideration.
2) In both sexes, the mortalities of cancer and cerebrovascular diseases in the group of ‘Relative weight≤-10%’ were highest among the four groups, whereas such mortalities in the group of ‘+10%≤ Relative weight<+20%’ were lowest. However, the differences controlled for age in the mortality of these diseases between the two groups were not significant at the 0.05 level in both sexes. The relation of relative weight to mortality for heart diseases was similar to that for cancer and cerebrovascular diseases in females, but the relationship between relative weight and heart disease mortality was not clear in males.
3) The prevalences of hypertension, heart diseases, cerebrovascular diseases, diabetes mellitus or other major chronic diseases in the group with a relative weight≤-10% were not high as compared with those in all other groups at baseline.
4) These results suggest that leanness without manifest chronic diseases should also be considered as an important health problem in aged individuals living in Japanese rural areas.
