Body size and risk for clinical fractures in older women. Study of Osteoporotic Fractures Research Group.

Background: Small body size predicts hip fractures in older women.

Objective: To test the hypothesis that small body size predicts the risk for other clinical fractures.

Design: Prospective cohort study.

Setting: Population-based listings in four areas of the United States.

Patients: 8059 ambulatory nonblack women 65 years of age or older.

Measurements: Weight, weight change since 25 years of age, body mass index, lean body mass and percent body fat, and nonspine fractures during 6.4 years of follow-up.

Results: Compared with women in the highest quartile of weight, women in the lowest quartile had relative risks of 2.0 (95% CI, 1.5 to 2.8) for hip fractures, 2.3 (CI, 1.1 to 4.7) for pelvis fractures, and 2.4 (CI, 1.5 to 3.9) for rib fractures. Adjustment for total-hip bone mineral density eliminated the elevated risk. Results were similar for other body size measures. Smaller body size was not a risk factor for humerus, elbow, wrist ankle, or foot fractures.

Conclusions: Total body weight is useful in the prediction of hip, pelvis, and rib fractures when bone mineral density has not been measured.