Hip fractures, which strike 250,000 Americans a year, most of them women, are among the most devastating problems of old age. But a study published in the New England Journal of Medicine says there is much women can do to reduce their risk.
The four-year study, led by Dr. Steven R. Cummings, an epidemiologist at the University of California School of Medicine in San Francisco, followed more than 9,500 white women over 65 who had never had a hip fracture. It found that the more risk factors a woman had, the higher her chance of a broken hip.Overall, a white woman has a 1-in-6 chance of a hip fracture over her lifetime, and a black woman has a 1-in-20 chance.
In addition to low bone density, a major risk factor, the researchers found that risk went up if a woman had lost weight since age 25, if she had had a mother who had broken a hip (especially before 80) and if she had herself broken a bone after age 50.
The risk also went up with increasing caffeine consumption, if a woman had been tall in her youth, if she smoked, had poor vision or took insomnia or anxiety drugs that raise the likelihood of falling.
The team also found that taking estrogen after menopause reduces risk, though few women in the study were taking it, and that, as other studies have shown, calcium from food did not reduce risk, although data on this were limited. The team has not finished research on calcium supplements and hip fractures.
The National Institutes of Health applauded the study, especially the finding that women can reduce their risk.
According to the NIH, ways to reduce risk include: walking for exercise, quitting smoking, reducing caffeine, avoiding long-acting sedatives, maintaining bone density through estrogen replacement or other therapies - and maintaining body weight.
Compared to heavy women, thin women have a greater risk of hip fracture, Cummings said, perhaps because excess weight on bones helps maintain bone density, because fat tissue helps make estrogen or because fat acts as padding in falls.