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MONDAY, July 28, 2003 (HealthDayNews) -- While women have long been alert to the dangers of osteoporosis as they age, few men worry about weakening bones.
They should, new research shows.
As many as 2 million American men have the bone-thinning disease, according to the National Institutes of Health. And men over 50 are at greater risk of osteoporosis-related fractures than they are of prostate cancer, the National Osteoporosis Foundation says.
That 2 million figure pales when compared with the 8 million U.S. women with osteoporosis. But doctors and researchers are zeroing in on the fact that men can get osteoporosis and be successfully treated, too.
"The importance of men's bone health is starting to get on the radar screen," says Dr. Pamela Taxel, an endocrinologist at the University of Connecticut Health Center and a specialist in osteoporosis and men.
The National Osteoporosis Foundation reports that one in eight men over 50 at risk of the disease will experience an osteoporosis-related fracture. And mortality in men one year after a hip fracture is twice that of women.
These figures, combined with the aging of the U.S. population, spurred the National Institutes of Health's Institute of Arthritis, Musculoskeletal and Skin Diseases to begin in 1999 a $24 million, seven-year, seven-site study of 5,700 men over 65 to identify the prevalence and risk factors for osteoporosis.
Men are less susceptible than women to osteoporosis because they have bigger bones to start with, their bone loss begins later in life and progresses more slowly. And they don't have the rapid hormonal changes that women face during menopause, adds Dr. Clifford J. Rosen, director of the Maine Center for Osteoporosis Research and Education.
But as men move into their 70s and beyond, their bone loss increases to the same level as women's, says Rosen, who recently gave an overview of research into men's osteoporosis at the annual meeting of the American Association of Clinical Chemistry in Philadelphia.
It isn't known why some men get osteoporosis and others don't. But scientists are looking at gender-specific genetic characteristics that might make some men vulnerable to the disease. They're also studying the protein IGF profactor-1, which could contribute to osteoporosis in men, Rosen says.
Also interesting, Rosen says, is new research that shows the tissue that makes up the outer cortex of the bone can increase in adulthood.
An article by Swedish scientists in the July 24 issue of the New England Journal of Medicine found women can gain bone size in the outer tissue of the bone while bone density of the inner part of the bone is decreasing. This increase in size could be more pronounced in men because of their bigger bones, and could be another reason why men are at lower risk for osteoporosis, Rosen says.
"It could be that the male response to this phenomenon is more vigorous and more expansive, so that the outer circumference of the bone is more responsive to signals, whatever they are," he says.
Also of interest is the effect of men's estrogen levels on their bone health, says Taxel, which could lead to new treatments for men. "Not only testosterone but also estrogen may be important in men's bone health," she says.
At present, there are no guidelines recommending that all men should have bone-density screening tests, as there are for women. But Taxel says testing would be medically prudent.
Men who should have bone-density screening tests include those older than 55 who have lost 2 inches of height. So should men who've had a bone fracture that wasn't caused by a major trauma, such as a car crash, but a simple fall -- "a fragility fracture," Taxel says.
Other known risk factors for men, most of which parallel the risks for women, include a family history of the disease, kidney stones, alcoholism, smoking and taking steroid medications.
Men with problems with male hormone production and those on medication for prostate cancer that suppresses hormone production also should be tested.
Taxel says studies are showing the osteoporosis drugs approved for women have similar benefits for men. These include Fosamax, a brand name for alendronate sodium, which increases bone density and lowers the risk of fracture, and Actonel.
A newer drug called teriparatide, manufactured by Eli Lilly and Co. and sold under the brand name Forteo, also shows promise. It increases the action of bone-building cells called osteoblasts, which in turn increases bone density. This drug, however, has to be injected daily, so it's only used for very ill patients, Taxel says.
Men with osteoporosis are also urged to increase calcium and vitamin D intake and exercise regularly, Rosen says.
More information
The U.S. Food and Drug Administration has more information on men and osteoporosis. The American Medical Association has an article that says men are less likely than women to receive treatment for osteoporosis after sustaining a hip fracture.
