Which Fractures Are Associated with Low Appendicular Bone Mass in Elderly Women?

Abstract

OBJECTIVE: To determine which types of fractures have an increased incidence in elderly women with low appendicular bone mass. DESIGN: Prospective cohort study. SETTING: Four clinical centers in the United States (Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; Monangehela Valley, Pennsylvania); and one coordinating center in San Francisco, California. SUBJECTS: Ambulatory, nonblack women (9704) aged 65 years or more who were recruited from population-based listings. MEASUREMENTS: We measured bone mass at the distal and proximal radius and calcaneus using single-photon absorptiometry. Fractures were verified radiographically. Associations were calculated as age-adjusted hazard ratios (with 95% Cls) per standard deviation decrease in bone mass. MAIN RESULTS: During a mean follow-up of 2.23 years, 841 nonspinal fractures occurred in 753 women. The risks for fractures of the wrist, foot, humerus, hip, rib, toe, leg, pelvis, hand, and clavicle were significantly related to reduced bone mass (P less than 0.05). These fractures represented 74% of nonspinal fractures. The overall hazard ratio for the occurrence of one or more of these fractures was 1.65 (Cl, 1.49 to 1.82) at the distal radius. In a subsample of the cohort, vertebral fractures were also related to low bone mass. Fractures of the ankle, elbow, finger, and face, however, were not associated with bone mass at any measurement site; the overall hazard ratio for these fractures was 1.12 (Cl, 0.96 to 1.30) at the distal radius. CONCLUSION: Most types of fractures have an increased incidence in elderly women with low bone mass.