News Release

Study: osteoporosis doubles risk of fractures in nursing homes

Peer-Reviewed Publication

University of North Carolina at Chapel Hill

CHAPEL HILL -- Doctors have known for years that osteoporosis boosts the risk of bone fractures, especially among elderly women who live at home. Now, the first large study to examine fracture rates of women living in nursing homes found that low bone mineral density -- especially among residents who are more active -- also puts those women at a higher risk of fractures.

A report on the research appears in the current issue of the Journal of the American Medical Association. Conducted at the University of Maryland School of Medicine in Baltimore, the study showed that women who had bone density levels below the nursing home average were more than twice as likely to suffer a fracture than women with higher-than-average bone density levels. The risk was more than three times greater for residents with low bone density who also had the ability to move around independently.

"Activity is good, but nursing home residents with better mobility are also more vulnerable to falls," said lead researcher Dr. Sheryl Zimmerman, associate professor of epidemiology and social work at the University of North Carolina at Chapel Hill School of Public Health. "Mobility and low bone mineral density work together to dramatically increase the risk of fracture."

Zimmerman also co-directs the Program on Aging at the Cecil G. Sheps Center for Health Services Research. Her study involved more than 1,400 white women from 47 randomly selected nursing homes across Maryland. Researchers found that 80 percent of the women had osteoporosis, which means that they had low bone mineral density and weak, brittle bones. Those with the lowest levels of bone density had the greatest fracture rates.

"Hip fractures are a very debilitating injury for elderly nursing home residents," said Dr. Jay S. Magaziner, professor of epidemiology and director of the division of gerontology at the University of Maryland's department of epidemiology and preventive medicine. "A quarter of those who suffer a hip fracture die within a year, and more than half of the survivors never regain the level of functioning they had before the fracture." Using a van equipped with special equipment to test bone mineral density, researchers traveled to nursing homes to measure bone density in study volunteers' arms. Eighteen months later, they reviewed medical records of the participants to determine the number of new fractures. A total of 223 osteoporosis-related fractures occurred among 180 women in the study. Some women had more than one injury. Seventy-percent of the fractures resulted from falls.

The study focused on white women because they comprise two-thirds of the U.S. nursing home population, and the incidence of osteoporosis-related fractures is highest among elderly white women. All women who volunteered for the study were over age 65.

"Nursing home fractures are often associated with frailty and illness, but bone mineral density is not always considered to be an important factor," said Dr. Julie M. Chandler, associate director of epidemiology at Merck Research Laboratories. "Our research shows that bone mineral density is a main contributor to the fracture risk in nursing homes."

Investigators hope the data will help doctors and caregivers prevent fractures among nursing homes residents.

"In addition to evaluating a resident's bone strength, we should also consider their level of activity," said Zimmerman. "Although further study is needed, medications and dietary supplements to improve bone density or prevent bone loss may offer some protection. Patients who are more mobile may benefit from exercises to improve strength and balance and reduce the risk falling."

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Merck Research Laboratories and the National Institute on Aging supported the study.

Note: Zimmerman can be reached at (919) 962-6417.
Contact: David Williamson, (919) 962-8596.


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