Bone mineral density and bone loss measured at the radius to predict the risk of nonspinal osteoporotic fracture.

摘要

Low bone mineral density (BMD) and, probably, the rate of bone loss (RBL) are associated with the risk of osteoporotic fractures. To estimate the risk of nonspinal fracture in osteoporotic women, we measured BMD and RBL in a prospective study (average follow-up, 5.38 years) in 656 postmenopausal women. The women were considered in three groups: group A (whole population), group B (women under the age of 65 years) and group C (women over the age of 65 years). At the beginning of the study, BMD was measured at the distal radius (DR) and at the proximal radius (PR) using a single-energy densitometer. BMD measurements made 2 years previously in the same patients were used to calculate RBL. Then patients were checked annually for nonspine fracture due to minor trauma. During follow-up, 121 nonspinal fractures were detected. Women with fractures were older and had lower BMD. With the Cox regression, age-corrected BMD at both DR and PR predicts fracture risk in groups A and B but not in group C. After correction for potential confounders, DR still predicts fractures in groups A and B whereas PR predicts fractures only in group B. In group C, only the RBL at the PR was predictive of the fracture risk as well as in the other two groups. Specific types of fractures are predictable in the whole population at the wrist. In conclusion, radial BMD predicts the risk of nonspine fractures except in women over the age of 65 years. The RBL at the PR is an effective predictor of fracture risk also in women over the age of 65 years.