NEW YORK - More women should be getting tested for osteoporosis, a devastating bone disease that can lead to debilitating fractures, according to results from the largest U.S. study of osteoporosis risk factors, which was led by a physician from Columbia University College of Physicians & Surgeons.
The study of more than 200,000 women from 34 states found that almost half of women over age 50 who visit primary care doctors in the United States are at some risk for osteoporosis. The women had been patients of more than 4,000 primary care doctors between Fall 1997 and Spring 1999.
"Despite excellent diagnostic tools and safe therapies, osteoporosis and low bone density remain underdiagnosed," says Dr. Ethel Siris, the Madeline C. Stabile Professor of Clinical Medicine and lead author of the study. Dr. Siris is also director of the Toni Stabile Center for the Prevention and Treatment of Osteoporosis at Columbia Presbyterian Medical Center of NewYork-Presbyterian Hospital.
The findings of the study, called the National Osteoporosis Risk Assessment and which was sponsored by Merck & Co., are being published in the Dec. 12 issue of the Journal of the American Medical Association.
"The implications of the study should be meaningful to all women," Dr. Siris says. "As women age, they should work with their doctors to prevent osteoporosis, to get evaluated for it using bone mineral density measurement, and to get treated appropriately, if diagnosed with the disease."
Osteoporosis is a thinning of the bone that occurs because of exaggerated bone loss, which often happens after menopause. To prevent bone loss associated with osteoporosis, women should have enough calcium and vitamin D in their diets, stop smoking, and engage in physical exercise, Dr. Siris says. A variety of medications also are available to prevent and treat osteoporosis. A woman in her 70s who has osteoporosis also should "fall-proof" her house. For example, she should install a grab bar in the bathroom to prevent a fall that could lead to a fracture, which occurs in patients with osteoporosis because bones become brittle and frail.
To be included in the National Osteoporosis Risk Assessment, women had to be more than 50 years old, menopausal, and not previously diagnosed with osteoporosis. The researchers measured the bone mineral density of the forearm, finger, or heel of each woman in the study using a Food and Drug Administration-approved device. The physicians who participated in the research did so to learn more about the frequency and risk factors of osteoporosis to better treat patients in their practices.
"Physicians 20 years ago would say osteoporosis was an inevitable part of aging for women," Dr. Siris explains. "It has been only 10 years since there have been greater awareness of and more therapies for osteoporosis. It is taking time for the message to reach all doctors."
The investigators collected an enormous amount of health information from the women, such as medication and hormone use, alcohol consumption, smoking status, fracture history, and mother's history of osteoporosis. They also asked the women to answer a questionnaire about fractures and other medical issues one year after their initial evaluation. The JAMA article analyzes the baseline and one-year of follow-up data. The researchers plan to do additional follow-up studies.
The researchers found that risk factors for osteoporosis for the women in the study were increasing age, a personal or family history of fracture, Asian or Hispanic heritage, smoking, and the use of glucocorticoids, any of a group of steroid hormones from the adrenal gland that are used to treat a variety of medical conditions.
High body mass index, African American heritage, estrogen or diuretic use, exercise, and alcohol consumption decreased the likelihood of osteoporosis among the women in the study. Body mass index is a measure of weight to height and is associated with body fat and health risk.
From the bone density measurement, the investigators characterized the women as being normal or having either osteoporosis or osteopenia, a precursor condition to osteoporosis. They found that 39.6 percent of the 200,160 women in the study had osteopenia and 7.2 percent had osteoporosis, which translates to nearly 50 percent having some risk for osteoporosis.
Although the gold standard to measure bone mineral density is dual X-ray absorptiometry (DXA) of the hip and spine, or the central skeleton, the study found that measurements of bone mineral density at peripheral sites (such as the forearm, finger and heel) can predict future fracture risk. Among the 163,979 participants who underwent peripheral measurement and provided one year of follow-up information, osteoporosis was associated with a fracture rate four times that expected in normal women; osteopenia had fracture rate nearly twice that of normals. Fractures of the hip, wrist, rib, and spine were included in the rate.
The researchers acknowledge that the population of women in the study is not a representative sample of women in the United States. The women in the study had primary care physicians, chose to participate, and were not randomly selected to mirror the socioeconomic and general health of U.S. women. The study also had a smaller percentage of minorities than exist in the country, although the actual number of African American, Asian, Hispanic, and Native American women who participated was larger than in previous studies. Future studies will further analyze risk factors and ethnicity.
According to the National Osteoporosis Foundation:
- Osteoporosis affects 28 million Americans, 80 percent of whom are women.
- One in two women over age 50 will have an osteoporosis-related fracture in her lifetime.
- Women can lose up to 20 percent of their bone mass in the five to seven years following menopause, putting them at risk for osteoporosis.
- Osteoporosis is responsible for more than 1.5 million fractures annually in the United States, including 300,000 hip fractures and approximately 700,000 vertebral fractures, 250,000 wrist fractures, and 300,000 fractures at other sites.
- In 1995, the estimated cost in hospitals and nursing homes for osteoporotic and associated fractures was $13.8 billion. The cost today is much greater.
- Osteoporosis is often called a silent disease because bone loss occurs without symptoms. People most often become aware they have osteoporosis when a bump or fall causes a fracture.
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Journal
JAMA