Diseases and Causes of Death in the Aged

Based on the Hisayama Study

Abstract

Biophysical and biochemical characteristics of the aged were studied in a general population sample of 1, 621 or 2, 190 Hisayama residents aged 40 or over, which were screened at 1961 or 1978, respectively. The cause-specific mortality was compared between the earlier (1961-69) and the later cohort (1974-82) of the study during the initial 8 year of surveillance. This could allow us to estimate the changing pattern of the diseases in the aged over a 13-year period. In addition, 769 consecutive autopsy-cases of the Hisayama residents were examined to elucidate clinical and pathologic features of the diseases in the senescence. Body-mass index for both sexes decreased with advancing age-decade, and this trend was more proiment for males. Reduction in weight of brain, liver or kidneys of the autopsied cases aged 30 or over, was in progress with a decade of increasing age. Changes in blood chemical constituents by age-decade varied according to sex, namely, each constituent had its own pattern of ageing by sex. Systolic blood pressure developed a tendency to increase with progressing age, but a standard deviation of averaged systolic pressure became larger in the aged group. This variation was due to the difference in age-related changing pattern of systolic pressure each by each. An impact of hypertension as a risk factor for cardiovascular disease was less significant in the senescence, but systolic hypertension was not necessarily innocent for the development of cardiovascular disease in the elderly subjects. The frequency of deaths from cerebral stroke, heart diseases, or malignant neoplasms increased stepwise with advancing age-decade in both sexes. Recently, a total mortality in the residents of 7th, 8th and 9th decades, however, declined in the community of Hisayama. This was in part due to the reduction of the incidence of cerebral stroke in the aged population. Clinical pictures of cerebral storke, myocardial infarction, or malignant neoplasma were sometimes latent and unusual in the patients above the age of 70 years when compared with those below 70. The incidence of recurrent episodes of cerebral stroke was not so much in the old patients, but multiple ischemic lesions on the brain severely affected a daily activity of the patients. The frequency of double cancers increased with advancing agedecade and 10.2% of the autopsy-cases with malignant neoplasms aged 80 years or over. Vascular or senile dementia was found in 3.8% of the total consecutive autopsies, respectively, and senility was noted only in 1.2%. Pneumonia in the senescence was significant as an underlying cause of death and is likely to have a great influence on life expectancy of the aged.