We measured the bone mineral density (BMD) of the cortical and cancellous bone of the lumbar spine in women by using QCT to evaluate the influence of the aging process and menopause on both bones.

The BMD of cancellous and cortical bone in L1, L2 and L3 was assessed by QCT in 510 patients from 1997 to 1999.

The rate of cancellous bone loss was more markedly increased than that of cortical bone with aging process and menopause, while the density of cortical bone was more effective to whole bone density. Cortical bone density and whole bone mineral density were higher in L3 than L1 vertebra. On the contrary, the cancellous bone density was higher in L1.

The BMD of cancellous bone decreased a lot more than that of cortical bone in postmenopausal women. We conclude that preventing cancellous bone loss is of the utmost importance for the prevention of osteoporosis after menopause.