Utility and validation of bone mineral density measurements at forearm in predicting trabecular microarchitecture and central-site osteoporosis in aging Indian postmenopausal women-a promising surrogate?

Objective: The objective of this paper was to present the results of our study of the utility of bone mineral density (BMD) measurements at various segments of distal forearm in predicting central-site osteoporosis and deteriorated trabecular microarchitecture.

Methods: This was a cross-sectional study and BMD at the femoral neck, lumbar spine, and distal forearm were assessed using the dual-energy X-ray absorptiometry (DXA) scanner and bone microarchitecture at lumbar spine by trabecular bone score (TBS). The utility of forearm BMD in predicting osteoporosis as well as the deteriorated TBS was assessed by a receiver operating characteristic analysis.

Results: A total of 352 postmenopausal women with mean (SD) age of 60.7 (6.8) years were included. The odds of having osteoporosis at femoral neck [odds ratio (OR) = 14.1, 95% confidence interval (CI): 7.8-25.2] and lumbar spine (OR = 7.5, 95% CI: 4.6-12.1) was highest with the mid-distal radius. A derived -score cut off ≤ -1.6, -1.9, and -1.7 at any segment of the forearm was elucidated to predict osteoporosis at the central-site, femoral neck, and lumbar spine, respectively, with sensitivity of 80%-88% and specificity of 60%-70%. The -scores at all three forearm segments ≤ -1.2 showed fair performance in predicting degraded trabecular microarchitecture. The -scores thus derived were further validated in cohort of 360 Bengali postmenopausal women.

Conclusion: BMD assessment at the forearm may be utilized in prediction of trabecular microarchitecture and central site osteoporosis at the femoral neck and lumbar spine in postmenopausal women.