[Postmenopausal bone loss: results of a topographic study by X-ray absorptiometry]

Bone density was determined in six areas (head, arms, thorax, spine, legs, and pelvis) using total body dual photon X-ray absorptiometry. Values were compared with the conventional anterior-posterior lumbar spine (L2-L4) absorptiometry measurement in 20 young females (25 +/- 4.2 years), 41 perimenopausal females (51 +/- 2 years), and 39 postmenopausal females (time since menopause 2.7 +/- 1.9 years). The two older groups were of similar age and physical characteristics. Total body bone mineral density and leg bone mineral density were significantly lower in the perimenopausal women than in the younger women, but this difference was no longer apparent after adjustment for height. Postmenopausal women exhibited diffuse bone loss with a particularly marked decrease in the lumbar spine measurement. Lumbar bone mineral density was significantly correlated with bone mineral densities at other sites; correlation coefficients ranged from r = 0.56 for the head to r = 0.83 for the total skeleton. However, one third of females with a lumbar measurement predictive of a high fracture risk had normal bone mineral density at another site, and vice versa. Our findings show that postmenopausal bone loss affects the entire skeleton and that measurements should be performed at several sites in order to identify high-risk women at cessation of menses.