Physiological and biochemical changes in ageing--based on a population survey in a Japanese community, Hisayama

Biophysical and biochemical characteristics of the aged were studied in a general population sample of 1,621, 2,008 or 2,146 Hisayama residents aged 40 or over, which were screened at 1961, 1973-74 or 1983, respectively. In addition, 769 consecutive autopsy-cases of the Hisayama residents were examined to elucidate age-related reduction in weight of various organs. Body-mass index for both sexes decreased with advancing age-decade, and this trend was more prominent for males. A slight acceleration in the biennial changes in body-mass index for males was found during the fifth decade of life and a slight attenuation during the seventh decade, although the magnitude of the change is small. 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. Both systolic and diastolic blood pressures rose with increasing age until the 7th decade. Thereafter, systolic pressure continued to rise while diastolic pressure began to drop in advanced age for both sexes. A standard deviation of average systolic pressure in both borderline cases and normotensives became larger along the time-course in the aged. This variation is probably due to the difference in age-related changing pattern of systolic pressure each by each, particularly in borderline hypertensives. Changes in blood chemical constituents by age-decade varied according to sex, namely, each constituent had its own pattern of ageing by sex. Based on the results from the present study, basic morphology or physiology related to ageing was discussed.