A team from the USA investigated the occurrence of low bone mineral density (BMD) in postmenopausal women, its risk factors, and fracture incidence during short-term follow-up.
The National Osteoporosis Risk Assessment was initiated in September 1997 to March 1999, with approximately 12 months of subsequent follow-up.
A total of 200,160 ambulatory postmenopausal women, aged 50 years or older, with no previous osteoporosis diagnosis were included in the study. The patients were derived from 4236 primary care practices in 34 states.
Baseline BMD T scores, obtained from peripheral bone densitometry performed at the heel, finger, or forearm, were measured. In addition, risk factors for low BMD derived from questionnaire responses, and clinical fracture rates at 12-month follow-up were assessed.
Using World Health Organization criteria, 39.6% were found to have osteopenia (T score of -1 to -2.49) and 7.2% had osteoporosis (T score ≤ -2.5).
The researchers found that age, personal or family history of fracture, Asian or Hispanic heritage, smoking, and cortisone use were all associated with significantly increased likelihood of osteoporosis.
|Prevalence of condition:|
| Journal of the American Medical Association |
Conversely, higher body mass index, African American heritage, estrogen or diuretic use, exercise, and alcohol consumption significantly decreased the likelihood.
Among the 163,979 participants with follow-up information, osteoporosis was associated with a fracture rate approximately 4 times that of normal BMD. Osteopenia was associated with a 1.8-fold higher rate of fracture.
Dr Ethel S. Siris, of the Columbia University College of Physicians and Surgeons, New York, said on behalf of her colleagues, "Almost half of this population had previously undetected low BMD, including 7% with osteoporosis.
"Peripheral BMD results were highly predictive of fracture 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," she concluded.