Drugs raise bone health
But prevention
is still the best way to steer clear of osteoporosis
By Linda Carroll
SPECIAL TO MSNBC
Recently retired, Nancy Dyer and her husband were walking along a Florida beach when
she suddenly felt pain from her toes to her heels.
At first she thought the excruciating pangs were from insect bites. But when she went to
the doctor, Dyer learned differently: Her bones had become so weakened by undiagnosed
osteoporosis that just the weight of her body had been enough to fracture all the bones in
her feet.
Until recently, there were few options once the disease had already become so advanced.
But that’s all changing with the development of new drugs, though experts continue to
stress that an ounce of prevention is worth a pound of cure.
MORE DEADLY THAN CANCER
A potentially deadly condition, osteoporosis affects more women than breast, uterine and
ovarian cancers combined. As many as 20 percent of its 28 million victims, two-thirds of
whom are women, end up in nursing homes. Fifty thousand Americans die each year
from post-fracture complications, according to experts on the disease.
But, unlike cancer, osteoporosis can be prevented through lifestyle changes. And for
women susceptible to the condition, a host of new drugs have been developed to halt —
and in some cases even reverse — the progress of the bone-eating disease.
Through diet and exercise, women can stave off osteoporosis — especially if they start at
a young age, according to Dr. Robert Recker, a professor of medicine and director of the
Osteoporosis Research Center at the Creighton University School of Medicine in Omaha.
Almost 60 percent of bone is built in the teen years. Young people need to build and
bank bone for their old age, just as they might stash away money for their eventual
retirement, Recker says.
Throughout one’s life, bone, like skin, is constantly being destroyed and rebuilt —
experts believe this is how bone retains its elasticity. Bone-eating cells, called
osteoclasts, chew holes in the bone. Bone-forming cells, osteoblasts, which use calcium
as the building blocks, then fill in these cavities.
KEY CHANGE AT 30
Up to age 30, the bone-forming cells work faster than the bone-destroying cells, and
bones thicken. After that, the osteoblasts slow down and the osteoclasts take over,
eroding bone and leaving tiny pits that are never filled in.
Women who build up bone before age 30 are less likely to suffer fractures as they age,
according to Dr. B. Lawrence Riggs, Purves professor of medical research at the Mayo
Medical School and Mayo Clinic in Rochester, Minn. To accumulate bone, young
women must get lots of calcium and engage in regular weight-bearing exercise, he says.
Weight-bearing exercise is exercise that forces one to work against gravity — such as
walking or jogging, racquet sports, hiking, aerobic dance and stair climbing. Young
women should get at least 1,000 mg of calcium per day, Riggs says. And they should
avoid cigarette smoking, excessive alcohol use and colas because they all interfere with
bone building. Carbonated cola beverages, for example, contain phosphates, which steal
calcium from bones by driving down the level of the mineral circulating in the blood.
You can check if your soda contains phosphates by looking for phosphoric acid on the
label.
But women between 30 and 50 shouldn’t neglect their bones either, Recker says.
Exercise and dietary calcium or supplements can slow bone loss during these years.
During the first five years after menopause — when women’s estrogen levels plummet —
bones are particularly susceptible to thinning. For this reason, doctors often encourage
women to take estrogen-replacement therapy to replace the body’s natural loss of estrogen
and protect their bones.
But for some women, the decision to take estrogen is a tough one. Some studies have
shown a slight increase in breast cancer risk in women who take estrogen supplements.
For women with a family history of breast cancer, the prospect of estrogen-replacement
therapy can be frightening.
Fortunately, there are now other options. Alendronate, sold under the brand name
Fosamax, has been available for the past several years as a bone builder in patients who
have diagnosed osteoporosis. But based on new data, a U.S. Food and Drug
Administration advisory panel last month recommended that the drug be approved for the
prevention of the disorder as well.
BONE SEEKERS ON THE LOOSE
“Alendronate seeks out bone,” explains Dr. Ethel Siris, the Madeline C. Stabile professor
of clinical medicine and director of the Toni Stabile Center for the Prevention and
Treatment of Osteoporosis at the Columbia Presbyterian Medical Center in New York.
“And then it blocks the marauding osteoclasts
A recent study that followed 2,000 women with at least one prior fracture found that
women who took alendronate were 50 percent less likely to develop a new fracture than
women who did not take the drug.
“This suggests that it’s never too late to prevent fractures in women with osteoporosis,”
says study leader Dr. Steven Cummings, a professor of medicine and epidemiology at the
University of California at San Francisco.
Researchers say that while alendronate can add bone, it isn’t a panacea because its bonebuilding capabilities are limited to about 5 percent.
Calcitonin, sold as Miacalcin, also helps build bones, and is usually prescribed to women
who cannot or choose not to take estrogen. In women who are at least five years beyond
menopause, calcitonin slows bone loss, increases spinal bone density and, according to
anecdotal reports, relieves the pain associated with bone fractures, says the National
Osteoporosis Foundation.
And new studies indicate calcitonin may reduce the risk of spinal and hip fractures as
well. Formerly available only as an injection, it is now available as the nasal spray — a
mode of delivery that many patients prefer.
Soon, there may be other options. A new designer estrogen is in its final stages of study
for FDA approval. The drug, raloxifene, behaves like estrogen in some parts of the body
— slowing down the osteoclasts and their resulting weakening of the bone, for
example— and like an anti-estrogen in the breasts, says Dr. Felicia Cosman, a researcher
currently studying the new medication. Researchers aren’t sure yet, but they believe that
raloxifene may actually protect women from breast cancer.
Another benefit for postmenopausal women is raloxifene’s lack of effect on the uterus,
says Cosman, an osteoporosis specialist at the Helen Hayes Hospital in West Haverstraw,
N.Y., and an associate clinical professor of medicine at the Columbia Presbyterian
Medical Center in New York City. While estrogen-replacement therapy often brings a
return of menstruation — something many postmenopausal find bothersome —
raloxifene does not, she explained.
BETTER DRUG AHEAD
And a still better drug may be on its way. In early tests, parathyroid hormone appears to
add as much as 25 percent to 30 percent in the spinal area, according to Recker. “We’re
talking cure now,” he says. “That’s if we can make it work. A lot more research still
needs to be done on this drug.
For Nancy Dyer, the new drugs may help make up for a lifetime of damage. “From what
I’ve been reading, I did everything wrong,” she says. “I smoked. I didn’t have regular
weight-bearing exercise. And until last year when Fosamax came out, there was nothing I
could do. There was just a steady deterioration of my bones.”
Now, doctors are seeing some improvement in Dyer’s bone density. “If you ask me what
I would like to do now,” she says. “I’d just like to get to the point where I could walk a
mile or dance a little.”