MONDAY, Feb. 18 (HealthDay News) -- Glucosamine sulfate, a popular dietary supplement purported to ease the pain and inflammation of arthritis, does not seem to help people with arthritis in their hips.

That's the conclusion of a study that compared the use of glucosamine to a placebo for the treatment of mild to moderate hip arthritis.

"For these patients with hip osteoarthritis, glucosamine sulfate does not seem to be an effective treatment on the basis of our results," said study author Rianne Rozendaal, a researcher at Erasmus Medical Center in Rotterdam, The Netherlands.

Not everyone is so certain that glucosamine isn't useful though.

"This study is not definitive. This is the first one specific on hip osteoarthritis, and only subgroups of patients improved. So, no confirmation, but no refuting either," said Dr. Johannes W.J. Bijlsma, the author of an accompanying editorial and chair of the department of rheumatology and clinical immunology at the University Medical Center Utrecht, in The Netherlands.

Results of the study appear in the Feb. 19 issue of the Annals of Internal Medicine.

As many as one in five Americans has been diagnosed with arthritis, according to the U.S. Centers for Disease Control and Prevention, and arthritis is the leading cause of disability in the United States.

While lifestyle interventions, such as exercising, can help prevent some of the disability associated with arthritis, few effective medical interventions are available. That may explain why people with arthritis turn to unproven remedies in the hope that these products might ease the pain in their aching joints.

Glucosamine sulfate is one such product, but clinical trials of the supplement have had mixed results. For every study that finds a benefit, it seems there's another that finds none. However, no studies had been done looking specifically at glucosamine's usefulness for arthritis of the hip, according to Rozendaal.

This double-blind randomized study included 222 people who had mild to moderate osteoarthritis of the hip. For two years, half the group took 1,500 milligrams of glucosamine daily and the other half took a placebo.

Pain and function levels were measured at the start of the study, and again every three months for two years. X-rays of the affected joint were taken at the start and end of the study to see if there was any improvement.

At the end of the study, the researchers found no evidence that glucosamine had any effect on pain or function, and they saw no improvement in the X-rays for people taking glucosamine. The researchers also conducted a small subgroup analysis on people with more severe arthritis, and found no benefit for this group either.

But another expert said the study contained what he called a "glaring error:" the fact that many of the patients had very low levels of daily pain.

"Patients in all groups had very mild pain. In other words, they don't have much room for improvement," said Dr. Jason Theodosakis, a consultant for the supplements industry and an assistant professor at the University of Arizona College of Medicine, Tucson.

"Patients with arthritis who have small amounts of pain -- not significant enough to inhibit sleeping, daily activities or work -- do fine without treatment. This is exemplified by the fact that only 19 percent of those in the placebo group were using daily medications," Theodosakis said. "I don't think conclusions should be drawn from the study."

Bijlsma agreed that the verdict is still out on glucosamine's effectiveness. Some studies have found that glucosamine is effective for knee arthritis, he noted, and because there are no good treatment options available for people with arthritis, Bijlsma said that taking glucosamine should remain an option for patients.

"I advise them to use it for three months; if they experience improvement, I advise them to continue. If there is no improvement, I advise them to stop. I'm aware that a lot of the osteoarthritis problems for patients are indeed symptoms [pain, stiffness] that are subjective, but patients can decide for themselves. In practice, between 60 and 70 percent of the patients continue this treatment for a more prolonged period of time," Bijlsma said.

More information

To learn more about osteoarthritis and available treatments, visit the U.S. National Institute of Arthritis and Musculoskeletal Diseases.

SOURCES: Rianne Rozendaal, M.Sc., researcher, Erasmus Medical Center, the Netherlands; Johannes W.J. Bijlsma, M.D., Ph.D., chairman, department of rheumatology and clinical immunology, University Medical Center Utrecht, the Netherlands; Jason Theodosakis, M.D., assistant professor, University of Arizona College of Medicine, Tucson; Feb. 19, 2008, Annals of Internal Medicine

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