August 14, 2002
Contact: John Iler, Warren Grant Magnuson Clinical Center Communications Office, (301) 496-2563
A study conducted at the Warren Grant Magnuson Clinical Center, National Institutes of Health (NIH) reports in the July 2 issue of the Annals of Internal Medicine that osteonecrosis of the hip may be a major complication for HIV-infected persons.
As HIV-related deaths and HIV-associated opportunistic infections have dramatically decreased, attributable in large part to new drug regimens introduced over the past decade, NIH researchers have noticed a disturbing increase in the incidence of osteonecrosis, or "bone death," of the hip in some HIV-infected patients.
"Osteonecrosis can eventually require hip replacement," said Dr. Joseph A Kovacs, head of the Critical Care Medicine Department's AIDS Section, and one of the researchers guiding the study. "We don't have a way to prevent it or treat it, except symptomatically, such as treating pain."
With disease progression, he explained, patients often report a persistent or debilitating pain. Eventually the dead bone collapses-a process that can take months or years. The pain can grow increasingly severe and a hip replacement is often ultimately required.
Osteonecrosis has also been associated with systemic lupus erythematosus, sickle cell anemia, and renal transplantation.
The NIH study began in 1999 after two HIV-infected Clinical Center patients were diagnosed with osteonecrosis within a four-day period. At the same time, other researchers were reporting increases in osteonecrosis in HIV-infected people, which had been first noted about 10 years ago.
The study used Magnetic Resonance Imaging (MRI) to look for the characteristic lesions in the hips of asymptomatic HIV patients. Between June and December 1999, adults enrolled in studies at the NIH Clinical Center, or who received health care at the National Naval Medical Center, Bethesda, Md., were invited to participate in a MRI screening study for osteonecrosis of the hip. Those who showed symptoms of the condition, which include pain or "groin pull," a pressure of the inner thigh, were excluded.
Of 339 patients studied, 15or 4.4 percent-were found to have osteonecrosis. This, said Kovacs, is considered "extraordinarily high" in any random group. None of the 118 HIV-negative participants, who were matched for age and sex, was found to have it.
In searching for possible causes, researchers found an association between osteonecrosis and the use of corticosteroids and other types of steroids such as androngenic and anabolic steroids, as well as lipid lowering agents. Kovacs explains that these are merely associations and that more research is required to try to find cause-and-effect relationships.
Corticosteroids are often administered to HIV-infected patients for HIV-specific complications such as pneumocystis pneumonia, as well as for common problems unrelated to HIV infection, such as severe allergies, bee stings, poison ivy, and severe asthma. The study indicated that many HIV-infected patients with osteonecrosis had been using the corticosteroids for only a short time. Anabolic steroids, such as testosterone, can be administered as replacement therapy in patients with testosterone deficiency but also is often used in body building.
Kovacs calls the study a "red flag" for doctors treating HIV-infected patients, should their patients complain of chronic hip or groin pain. He also believes doctors should be aware of the possible associations with osteonecrosis when prescribing treatments such as corticosteroids and testosterone in this population.
Due to the high cost of MRI scans, the unknown natural history of asymptomatic osteonecrosis, and the lack of treatment with documented efficacy for asymptomatic disease, the researchers at present don't recommend scanning patients unless they complain of persistent hip or groin pain.
For the complete study report refer to: http://www.annals.org/issues/v137n1/full/200207020-00008.html.
The Warren Grant Magnuson Clinical Center is the research hospital of the National Institutes of Health. Through clinical research, physicians and scientists translate laboratory discoveries into better treatments, therapies and interventions to improve the nation's health. NIH is an agency of the U.S. Department of Health and Human Services.