Assessment of bone mineral density in postmenopausal and senile osteoporosis using quantitative CT

The authors analyzed bone mineral density in 213 patients from January 1988 to September 1989. Bone mineral density of the vertebral body in the osteoporosis group of patients was compared with that in the normal group to investigate the correlation between bone mineral density and age distribution, and to estimate fracture threshold in the osteoporosis group. It was found that men, by linear regression, lose an average of 0.91% of bone per year, and women, by cubic regression, lose an average of 1.14% per year, accelerating at menopause. In the osteoporotic group, bone mineral density of men decreased an average of 29.7% compared with the non-osteoporotic group; that of women decreased an average of 29.9%. There was no difference between sexes. The fracture threshold of the osteoporotic patient was estimated to be about 90 mg/cm3.