R. Nuti et al., TOTAL-BODY, SPINE, AND FEMUR DUAL X-RAY ABSORPTIOMETRY IN SPINAL OSTEOPOROSIS, Calcified tissue international, 53(6), 1993, pp. 388-393
The aim of this study was to evaluate the ability of dual x-ray absorp
tiometry (DXA) to discriminate between normal and osteoporotic patient
s. A total of 152 postmenopausal women entered the study: 73 (aged 61.
2 +/- 8 years) had established postmenopausal osteoporosis with one or
more vertebral crushes on lateral X-ray of spine, and 79 (aged 59.3 /- 7.8 years) had no vertebral fractures. Measurements of bone mineral
content (BMC) in grams, bone mineral density (BMD) in g/cm2 and body
composition (lean and fat mass in grams) of total body, lumbar spine (
L2-L4), and femur (neck, trochanter, Ward's triangle) were carried out
with a LUNAR DPX densitometer. In all sites, BMD values of osteoporot
ic patients were significantly lower than those of the control subject
s. The higher Z-score was found for total body density (- 2.14) follow
ed by L2-L4 (- 2.0), femoral neck (- 1.93), Ward's triangle (- 1.69),
and trochanter (- 1.4). Only the trochanter Z-score was significantly
different compared with the other sites. A fracture threshold was dete
rmined for each site from osteoporotic patients and normal controls: w
ith a sensitivity set at 90%, the best specificity was obtained at the
lumbar spine and total body sites (89% and 84%, respectively). BMD va
lues were highly related to lean and fat body mass, but bone loss with
age was unrelated to soft tissue change. In conclusion, BMD measureme
nts at different skeletal sites enable detection of spinal osteoporosi
s although sensitivity for femoral areas was less with respect to tota
l body and L2-L4 BMD values.