Assessment of bone mineral density with dual energy X-ray absorptiometry in pre- and post-menopausal women

Background: Osteoporosis is a chronic disease that contributes substantially to decrease physical activity and decline in the quality of life. Osteoporosis can be diagnosed easily with the use of dual-energy X-ray absorptiometry (DXA) equipment. The aim of this study was to investigate the magnitude of bone loss on proximal femur and lumbar spine LS in pre- and post-menopausal women from Isfahan Osteoporosis Diagnosis Center (IODC) since 2005. Materials and Methods: Bone mineral density (BMD) measurements using DXA have been performed at IODC. 185 pre-menopausal and 174 early post-menopausal women were selected randomly. A Norland XR46 system was used for the investigations. The student Nest was done to find the difference between the T-scores of the femoral neck (FN) and lumbar spine (LS) in pre- and post-menopausal women. Results: Mean BMDs for the FN and LS in pre-menopausal women were 0.859 +/- 0.136 and 1.012 +/- 0.161 and in post-menopausal women were 0.816 +/- 0.119 and 0.919 +/- 0.140, respectively. Long-term BMD CVs of 1.0% and 1.2% for the LS and FN were found, respectively. The differences between the FN and LS for pre- and post-menopausal women were t = -9.02, p < 0.05 and t = -3.50, P < 0.05, respectively. Conclusion: In spite of, the reported lower BMD T-scores for the LS compared with the FN for women, we found that the FN had significantly lower T-score than LS for both pre- and post-menopausal women.