Bone changes occurring spontaneously and caused by estrogen in early postmenopausal women: a local or generalised phenomenon?

Regional values of bone mineral content and bone mineral density were calculated from total body dual photon absorptiometry scans of 52 early postmenopausal women treated with oestrogen for one year and of 52 similar women treated with placebo. The six regions were head, arms, chest, spine, pelvis, and legs. In addition, bone mineral density of the lumbar spine was measured by dual photon absorptiometry and bone mineral content of the forearm by single photon absorptiometry, using separate special purpose scanners. All regions were unchanged after one year of treatment with oestrogen, excluding the lumbar spine, for which values rose. Values for all regions except the lumbar spine fell significantly in the placebo group. The rates of loss ranged from 2% to 8%, with no significant differences among the regions. It is concluded that loss of bone in the early menopause is a generalised phenomenon, affecting all parts of the skeleton. Furthermore, oestrogen prophylaxis for loss of bone is effective in all parts of the skeleton. Finally, it is suggested that the measurement of bone mineral content in the forearm should be used for clinical follow up of bone changes, as this method is superior to others in the ratio of change to precision.