Bone Health of 40-Something HIV-Positive Men Similar to That of Uninfected Men Decades Older

Becky McCall

November 18, 2009

November 18, 2009 (Cologne, Germany) — A study of HIV-infected men with a median age of 46 years who were effectively managed on antiretroviral therapy showed an increased risk for osteopenia and osteoporosis, investigators announced here at the 12th European AIDS Conference/European AIDS Clinical Society.

Researcher Dominique Costagliola, PhD, a biostatistician from INSERM, Pierre and Marie Curie University in Paris, France, reported that the prevalence of osteoporosis in HIV-infected men was 7.87%, which is equivalent to the prevalence in men between the ages of 70 and 74 years in the general population. The median age of men enrolled in this study was nearly 30 years younger.

"It is striking that the risk is so much higher at a given age. I think there is something significant emerging as more and more HIV patients achieve a controlled level of viral load. We are beginning to see that the effects of HIV are not only mediated through immunodeficiency and viral replication, but through an important component, that of activation of the immune system. This aspect remains uncontrolled with current antiretroviral drugs," Dr. Costagliola told Medscape HIV/AIDS.

The prevalence of osteopenia and osteoporosis was estimated by screening bone mineral density at the lumbar spine and total hip using dual-energy x-ray absorptiometry during the ANRS 120 Fosivir trial. Osteoporosis was defined by a T-score equal to –2.5 and osteopenia by a T-score between –1 and –2.5. Various risk factors for bone loss were analyzed with multivariate logistical regression models.

Of the 700 men and 300 women participating in the ANRS 120 Fosivir trial, Dr. Costagliola's team focused on the data for men. Overall, 42% were smokers, median body mass index (BMI) was 23 kg/m2, median CD4 cell count was 496 cells/mL, and viral load was below 400 copies/mL.

Osteopenia was found in 33% of men at total hip screening and in 35% at lumbar spine screening. Osteoporosis was found in 4% and 6%, respectively. The most important risk factor for osteopenia and osteoporosis, at both the hip and spine, was a low BMI, Dr. Costagliola reported. A lower CD4 cell count was also associated with a higher risk for osteopenia and osteoporosis at the hip and of osteoporosis at spine. Older age was associated with risk for osteopenia and osteoporosis at the hip.

The researchers found a borderline significant association between cumulative exposure to protease inhibitors and the risk for osteopenia at the spine (odds ratio [OR], 1.05; 95% confidence interval [CI], 0.99 - 1.11). The first 2 years of exposure to tenofovir were also associated with an increased risk for osteopenia (OR, 1.59; 95% CI, 1.03 - 2.43) and osteoporosis (OR, 2.24; 95% CI, 1.01 - 5.00) at the spine and for osteoporosis at the hip (OR, 4.32; 95% CI, 1.53 - 12.21).

Dr. Costagliola believes that activation of the immune system by the virus might be responsible for a higher risk for other non-AIDS-associated problems. "Not only might activation explain osteoporosis but also risk of myocardial infarction, and certain non-AIDS cancers, which we see more frequently in HIV-infected patients."

"It's well known that in other diseases, such as rheumatoid arthritis, that are inflammatory in nature, there is an increased risk of osteoporosis and [myocardial infarction], but this is new for the field of HIV, which has focused on viral load and immunodeficiency. Now that these aspects of HIV are more or less controlled, we are beginning to see the other side of the coin."

Bill Powderly, MD, dean of the Medical School, University College, in Dublin, Ireland, highlighted the emerging idea that HIV is a chronic inflammatory disease of aging, rather than being an infectious disease per se. Dr. Powderly agreed that clinicians are now seeing comorbidities more familiar in the aging general population.

"There's an increased risk of bone disease. People are very concerned about this because osteoporosis is occurring 10 years earlier than it usually does. It is well recognized that in the elderly, somebody with a hip fracture is more likely to die in the following year because they are immobilized, they become frail, there's increased risk of developing pneumonias, so there's a big knock-on effect."

"One of the prevalent ideas in HIV at the moment is that some of the effects we are seeing in HIV patients are, in fact, diseases of the elderly. Is it premature aging? It's still a hypothesis, but it appears that diseases of aging occur much earlier in HIV patients. Smokers and injection drug users die younger. Is this immune activation by the virus?" asked Dr. Powderly.

Dr. Costagliola reports receiving sponsorship from most companies involved in the field of HIV research, including Bristol-Myers Squibb, Gilead, Abbott, Boehringer Ingelheim, MSD, Tibotec, Essex Pharma, GSK, Pfizer, Thera, and Roche. Dr. Powderly reports being a member of the data safety monitoring board for a number of trials sponsored by Tibotec.

12th European AIDS Conference/European AIDS Clinical Society (EACS): Abstract PS5/3. Presented November 12, 2009.

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