Until recently, osteoporosis was seen as a female disease. The number of cases of the bone- thinning disease in men, however, is on the upswing.
Estimates of the number of men suffering from osteoporosis in the United States reach as high as 4.5 million. Yet rarely do physicians mention the possibility of osteoporosis to their elderly male patients. Even if a doctor suspects a male patient has osteoporosis, “there are no approved therapies for treating it,” said Dr. Eric Orwoll, director of the Bone and Mineral Research Unit at Oregon Health Science University at the 1999 conference of the American Society for Bone and Mineral Research (ASBMR), held in St Louis September 27-30.
Osteoporosis is largely a disease of aging. As men live longer, “we are seeing more cases of osteoporosis,” says Dr. Anne Kenny, assistant professor of medicine at the University of Connecticut Center on Aging. The aging of the baby boom generation ensures that the number of men with the disease will swell, and studies suggest that the rate of osteoporosis among men is increasing, she says. Currently, men make up 20% of those afflicted with the disease.
More Fatal in Men
Bones are living tissues. As with any other living tissue, the body is constantly removing old tissue in a process called resorption and adding new tissue in a process called formation. Early in life, bone tissue formation out races resorption. At about age 35 in men, however, the pace of bone removal begins to outstrip the pace of bone formation, and men begin to lose bone mass.
“Men go through the same stages of bone loss as women, but about 10 years later,” says Orwoll. And as they lose bone mass, or density, their bones become more fragile and susceptible to breaking, especially in the hip, spine, and wrist. The kind of fall that would only bruise a healthy 30-year-old can break a bone in someone with osteoporosis.
“Fractures start to increase in men at about age 70 or 75,” says Kenny. Men suffer one-third of all hip fractures, or about 100,000 fractures a year, and they are “much more likely to end up in a nursing home following a hip fracture,” than are women, she says.
Men with osteoporosis also are more likely than women to suffer complications from broken bones. “The chances of a man dying within a year of a hip fracture are much greater than for women,” says Orwoll. Indeed, men are nearly twice as likely as women to die within a year after a hip fracture, and almost three times as likely as women to die within a year of a vertebral fracture. No one knows why.
First Treatments in Sight
Only recently have scientists begun looking for treatments for male osteoporosis. Scientists reported the results of the first successful clinical trials at the ASBMR meeting.
In general, scientists are looking at three possible therapies: testosterone supplementation, estrogen supplementation, and bisphosphonate therapy.
Kenny says that testosterone supplementation can prevent bone loss in men. Noting that testosterone levels fall in men as they age, she investigated whether bringing the hormone level back up to the level of a young man would arrest bone loss–and found that it did.
Other scientists are investigating whether estrogen supplements can prevent bone loss in men. Dr. Pam Taxol, also at the University of Connecticut Center on Aging, says such research was spawned by the discovery in the mid-1990s of two young men who, because of a genetic mutation, had no estrogen in their bodies. In both cases, the men suffered advanced osteoporosis that responded to estrogen therapies. Scientists now know that a healthy male body will convert some testosterone to estrogen and that estrogen levels fall in tandem with testosterone levels as men age. The question of whether estrogen supplements can help men with lowered estrogen levels is hotly debated.
The most promising therapy at the moment is bisphosphonate therapy, already used to treat osteoporosis in women. Bisphosphonates are nonhormonal drugs that reduce bone resorption. Orwoll says that one in particular, alendronate (Fosamax), is an effective osteoporosis treatment for men. He found from a 2-year clinical study that alendronate “increases bone mineral density and reduces height loss.” He says height loss, a common symptom of osteoporosis, is thought to result from spinal fractures.
Prevention Is Better
All three therapies have their drawbacks.
Many doctors fear testosterone plays a role in raising cholesterol and in initiating prostate cancers. Kenny says she found no evidence of that in her study. She attributes the fear of testosterone to the “bad press” it got from weight lifters abusing it.
Taxol says the main drawback to estrogen is psychological. She says male patients “invariably ask, ‘Are you trying to make me into a woman?'” Very high doses of estrogen are used to prepare men for sex change operations, while very low doses are used for treating osteoporosis.
Alendronate, however, has been associated with an increase in gastrointestinal disorders, such as acid regurgitation, abdominal pain, nausea, and throat ulcers and erosions. A study published last year in the Journal of Managed Care Pharmacy reported that nearly one-third of women using alendronate complained of such side effects, and almost half of them stop using the drug within 10 months.
To avoid those side effects, people taking alendronate are supposed to take it in the morning with water at least 30 minutes before eating. They must remain standing or sitting during that period.
Orwoll says his real hope is that the advent of treatments will convince doctors that male osteoporosis is real, and that they then will begin talking to their patients about it. Then steps can be taken to prevent the disease before it settles in.
Article By: Peter Downs, Medical Writer