Summary: We assessed the association between the rate of forearm bone loss and non-vertebral fracture. Bone loss at the distal forearm predicted fractures, independently of baseline BMD, but not independently of follow-up BMD in women. The BMD level where an individual ends up is the significant predictor of fracture risk.
Introduction: Bone loss may predict fracture risk independently of baseline BMD. The influence of follow-up BMD on this prediction is unknown. The aim of this study was to assess the association between bone loss and fracture risk in both sexes in a prospective population-based study.
Methods: We included 1,208 postmenopausal women (50 to 74 years), and 1,336 men (55 to 74 years) from the Tromsø Study, who had repeated distal and ultra-distal forearm BMD measurements. Non-vertebral fractures were registered from 2001 to 2005.
Results: A total of 100 women and 46 men sustained fractures during the follow-up time. Independent of baseline BMD, the RR associated with distal site bone loss of 1 SD %/year was 1.23 (1.01-1.50) for low-trauma fractures (excluding hand, foot, skull & high-trauma) and 1.32 (1.07-1.62) for osteoporotic fractures (hip, wrist and shoulder). However, bone loss did not predict fracture after adjusting for follow-up BMD. The BMD level where an individual ends up became the significant predictor of fracture risk and not the rate of bone loss. Follow-up BMD at ultra-distal site was associated with low-trauma fractures in both sexes. While ultra-distal site BMD changes were not associated with fracture risk in both sexes.
Conclusion: Bone loss at the distal forearm predicted non-vertebral fractures, independently of baseline BMD, but not independently of follow-up BMD, in women. The BMD level where an individual ends up is the significant predictor of fracture risk and not the rate of bone loss.