[Noninvasive study of the bone using single- and dual-photon densitometry: effects of age and menopause on bone density of normal and osteoporotic female population].

The assessment of bone status is so far usually performed by means of the relatively simple methods of radiographs and radiogrammetry, which are not always able to give a correct information about bone mineral content (B.M.C.) especially in cases of cortical osteoporosis. Among the other non-invasive methods, single- and dual-photon absorptiometry are of particular interest for their relatively low cost, precision, accuracy and repetitibility, giving the patient a very slight dose of radioactivity. Dual-photon device, in particular, offers the possibility to investigate B.M.C. in the bones surrounded with large amount of tissue, even in obese people. To assess bone status of feminine population, we have analyzed 238 patients, divided into 3 groups (normal pre- and post-menopausal women, and osteoporotic) measuring their radius and lumbar spine B.M.C. with single- and dual-photon absorptiometry. As a result, B.M.C. of both measuring sites appears closely correlated with age, and with the duration of menopause. In our group, cortical bone density showed a postmenopausal rate of loss higher than the trabecular. Vertebral measurements, too, were more closely correlated with age when corrected for body surface area. Osteoporotic group showed a B.M.C. significantly lower than the age-matched group of normal women both in spine and in radius: in conclusion, all these findings stress the importance of a widespread population surveillance in order to individuate and treat the patients at risk of spontaneous fractures.