Asthma treatment causes bone loss in young women

Inhaled steroids, widely used to treat asthma, cause bone loss in young women, researchers report.

Anti-inflammatory steroids taken in pill form are known to accelerate bone loss but it wasn't clear whether steroids inhaled directly into the lungs also thin bones.

Researchers at Boston's Brigham and Women's Hospital found a direct relation between the amount of inhaled steroids used and a decrease in bone density in the 109 women studied. Bone loss can lead to osteoporosis.

"The importance of this is that we know there's an effect, and the message really is we need to use inhaled corticosteroids at the lowest doses that we can," said Dr. Elliot Israel, one of the researchers.

The findings are reported in Thursday's New England Journal of Medicine. A second study in the journal shows an osteoporosis drug prevents bone loss in men getting hormone therapy for prostate cancer.

The studies provide further evidence that some medications promote bone loss, said Dr. Bess Dawson-Hughes of Tufts University, who wrote an accompanying editorial.

"There are ways — medical, nutritional and otherwise — to prevent some, if not all, of this medical therapy-induced bone loss," she said.

The inhaled steroids study looked at three groups of premenopausal women with asthma. One group did not use steroids to control their asthma. The two other groups used the same inhaled steroid, Azmacort, but at different doses.

Bone density was measured periodically over three years.

The researchers found small yearly decreases in bone density in the hip — but not the spine — in those who used inhaled steroids. Those who used higher doses had more bone loss.

Israel said inhaled steroids are effective in treating asthma, and their use shouldn't be discouraged. But patients should try to use low doses, get sufficient calcium and vitamin D, exercise and have their bone density checked, he said.

Israel and his colleagues only studied women but he said he would expect similar results in men who use inhaled steroids.

The second study was conducted at Boston's Massachusetts General Hospital and involved 47 men with advanced prostate cancer or a recurrence of the disease. It showed the drug Aredia, also known as pamidronate, prevented bone loss associated with hormone therapy for prostate cancer, which decreases testosterone levels.

One of the researchers, Dr. Matthew R. Smith, said hormone therapy is an overlooked cause of osteoporosis in men, who account for 20% of the 10 million cases of the brittle-bone disease.

In the study, half of the patients received intravenous treatments every three months of the hormone therapy Lupron Depot, also known as leuprolide, and Aredia. Half received only Lupron.

After nearly a year, those treated only with Lupron had a bone density decrease of 3% in the spine and nearly 2% in the hip. There was no significant change in bone density in those who were also given Aredia. The study was funded in part by Novartis Oncology, which makes the drug.

Dr. Felicia Cosman, clinical director of the National Osteoporosis Foundation, said more study is needed to see if the drug also reduces the risk of fractures or if easier-to-take oral osteoporosis drugs work in prostate cancer patients.

Drug-resistant HIV strains rising rapidly

Drug-resistant strains of HIV, the AIDS virus, have spread widely since the first effective drugs were introduced five years ago, making the deadly disease far tougher to treat, researchers reported Tuesday in the first large-scale study of the extent of HIV resistance.

The study, which focused on patients treated between 1996 and 1999, found that 78% harbored virus that was resistant to one class of drugs, 51% had virus that was resistant to two classes of drugs, and 18% had virus that was resistant to all three classes of drugs.

"The prevalence of resistance is much higher than we thought," says lead author Douglas Richman of the VA San Diego Healthcare System.

The ease with which HIV changes to protect itself against the most lethal drugs available represents evolution in action. Only the fittest viruses survive to multiply, quickly filling the void left by their more vulnerable ancestors. Moreover, the more resistant HIV there is, the more it will spread from person to person, Richman says. "I think this indicates why we're seeing much more transmission of drug-resistant virus."

Prior studies have shown that 10% to 20% of people newly infected with HIV carry drug-resistant strains.

The new study relied on blood samples taken from 1,083 patients who were no longer benefiting as much from their treatment. This population was statistically representative of 132,442 people treated between 1996 and 1999, says Richman, who collaborated with experts at the Rand Corp.

Jose Zuniga, director of the International Association of Physicians in AIDS Care, says doctors should test their HIV patients for drug-resistant virus after the drugs' benefits fade, so they can tailor therapy to the patient.

This isn't a simple matter, because current resistance tests measure resistance only in the most common AIDS strains. Resistance in up to half of the less common strains may be missed, and the results can be difficult to interpret. Zuniga notes that newer, better tests are in the works.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, called the study's results "striking," but he said that better tests are only part of the solution. "This is a wake-up call to develop new drugs."

Researchers say studies have shown that the $400 to $1,000 tests are cost-effective, because they spare patients costly treatment with ineffective drugs and keep them out of the hospital. One study, done in France, found that treatment failure adds $250 to the monthly cost of a patient's care.

The research also has implications for treatment in poor nations. These countries, now able to purchase discounted or generic versions of AIDS drugs, could experience the rampant spread of drug-resistant virus unless doctors prescribe the drugs properly and patients comply with their doctor's orders.

Otherwise, Zuniga says, the drugs will lose their potency and HIV will again become untreatable.

Richman presented his results in Chicago at the Interscience Conference on Antimicrobial Agents and Chemotherapy. He is a medical director of ViroLogic Inc. of South San Francisco, which makes the test used in the trial.