A June 12 Health article about bone loss incorrectly said that a recent New England Journal of Medicine study found a possible link between the osteoporosis drug Fosamax and atrial fibrillation, or irregular heartbeat -- a finding also suggested in earlier research. The NEJM study found such a link for another drug in Fosamax's class, but not for Fosamax. The earlier study found the suggestion of a trend between Fosamax use and atrial fibrillation, but one that did not reach levels of statistical significance.
Tuesday, June 12, 2007
I share an anxiety with several women friends in their 50s and 60s. We've all been told that because our bone mineral density is low -- though not low enough to meet the definition of the brittle-bone disease osteoporosis -- we need to take medication to reduce our chance of fractures. This means primarily hormones or Fosamax, the top-selling osteoporosis drug, for which doctors wrote more than 20 million prescriptions last year, nearly $2 billion worth. Knowing the associated risks -- heart disease, stroke and breast cancer for hormones; ulcers of the esophagus and stomach, and jaw decay for Fosamax -- none of us is eager to follow our doctors' orders.
Last month a study in the New England Journal of Medicine reinforced our concerns. The study found a possible link between the use of Fosamax and atrial fibrillation, or irregular heartbeat -- a finding also suggested in earlier research. "Doctors should think twice about whether there is really enough benefit to warrant the potential risk of treating women who do not have osteoporosis with Fosamax," said study author Steven R. Cummings, of the California Pacific Medical Research Institute in San Francisco.
I also suspect my friends and I are a lot less at risk than someone in my parents' generation. My mom and three of her pals have all fallen and had fractures; no one I know in my generation has done either.
My search of the scientific literature suggests we are right to be wary of over-medication.
Low bone density is only one of several well-established risk factors for bone fractures. Age and fracture history are just as important, according to Michael R. McClung, director of the Oregon Osteoporosis Center and a member of the council of scientific advisers for the International Osteoporosis Foundation. None of these factors alone is very good at predicting fracture risk. But some doctors don't appear to have gotten the message.
"Many younger women whose bone density is borderline low are getting treated, although their risk of fracture in the next five to 10 years is fairly low," said Nelson B. Watts, director of the University of Cincinnati Bone Health and Osteoporosis Center and chairman of the Food and Drug Administration's Advisory Committee for Endocrine and Metabolic Drugs. "And many patients who have had fractures are not being evaluated or treated, even though their risk of a second fracture in the next five to 10 years is fairly high."
That could soon change. Later this year, World Health Organization scientists plan to finish sifting data from several international osteoporosis trials and publish a new fracture-risk tool. The tool will combine bone density with about 10 other risk factors to gauge an individual's risk. Several national organizations, including the National Osteoporosis Foundation (NOF), hope to revise their osteoporosis treatment guidelines accordingly to reflect a truer picture of fracture risk. The new guidelines will recommend treatment if your risk of breaking a bone in the next 10 years is above a certain level, perhaps 25 percent.
Ethel Siris, professor of clinical medicine at Columbia University Medical School, is among those calling for a new standard of treatment. Measuring bone density, via an X-ray called a DXA scan (dual-energy X-ray absorptiometry), she says, is a useful diagnostic tool. "But bone density measurements were never intended to serve as a guide for when to treat this person and not that one," explained Siris, who is also president of the NOF.
An estimated 10 million people in the United States have osteoporosis, putting them at risk for fractures that, according to the Centers for Disease Control and Prevention, can lead to long-term disability or even death.
My friends and I are part of an even larger group -- about 34 million -- with low bone mass, or osteopenia. It's a "pre-disease" category fraught with controversy: Many argue it should be treated, lest it lead to a worsening problem.
Cummings and Watts, on the other hand, challenge the view of osteopenia as a condition to be treated. "It describes half the women over 50," said Cummings, who says the two most commonly prescribed osteoporosis drugs, Fosamax and Actonel, have shown no benefit in osteopenic women; only hormones, he said, have proved effective for this group.