1Columbia University College of Physicians and Surgeons, New York, NY
2Colorado Center for Bone Research, Lakewood
3University of California, San Diego, La Jolla
4Synarc, Portland, Ore
6Merck & Co Inc, West Point, Pa
Context: Large segments of the population at risk for osteoporosis and fracture have not been evaluated, and the usefulness of peripheral measurements for short-term prediction of fracture risk is uncertain.
Objectives: To describe the occurrence of low bone mineral density (BMD) in post- menopausal women, its risk factors, and fracture incidence during short-term follow-up.
Design: The National Osteoporosis Risk Assessment, a longitudinal observational study initiated September 1997 to March 1999, with approximately 12 months of subsequent follow-up.
Setting and Participants: A total of 200160 ambulatory postmenopausal women aged 50 years or older with no previous osteoporosis diagnosis, derived from 4236 primary care practices in 34 states.
Main Outcome Measures: Baseline BMD T scores, obtained from peripheral bone densitometry performed at the heel, finger, or forearm; risk factors for low BMD, de- rived from questionnaire responses; and clinical fracture rates at 12-month follow-up.
Results: Using World Health Organization criteria, 39.6% had osteopenia (T score of –1 to –2.49) and 7.2% had osteoporosis (T score ⱕ−2.5). Age, personal or family history of fracture, Asian or Hispanic heritage, smoking, and cortisone use were as- sociated with significantly increased likelihood of osteoporosis; higher body mass in- dex, African American heritage, estrogen or diuretic use, exercise, and alcohol con- sumption significantly decreased the likelihood. Among the 163979 participants with follow-up information, osteoporosis was associated with a fracture rate approxi- mately 4 times that of normal BMD (rate ratio, 4.03; 95% confidence interval [CI], 3.59-4.53) and osteopenia was associated with a 1.8-fold higher rate (95% CI, 1.49-2.18).
Conclusions: Almost half of this population had previously undetected low BMD, including 7% with osteoporosis. Peripheral BMD results were highly predictive of frac- ture risk. Given the economic and social costs of osteoporotic fractures, strategies to identify and manage osteoporosis in the primary care setting need to be established and implemented.