People with HIV have higher rates of bone fractures than HIV-negative people of the same age, according to a study published March 10 in Clinical Infectious Diseases. The risk is highest in those with low CD4 counts and people who also have diabetes or hepatitis C virus (HCV).

An increasing number of studies have documented higher rates of low bone mineral density (BMD) in HIV-positive people compared with their HIV-negative counterparts. In fact, a recent study that combined and analyzed data from multiple studies found that two thirds of people with HIV had low BMD and that 15 percent had the most severe form of bone mineral loss, called osteoporosis.

HIV-positive people with osteoporosis are generally younger than those with bone mineral loss in the general population, but because they're young, they are generally believed to be less prone than elderly adults to accidents that can cause a bone fracture and that often stem from reduced strength, balance problems and poor dexterity.

Unfortunately, new data reported by Benjamin Young, MD, from Rocky Mountain Cares/DIDC in Denver and his colleagues indicate that people living with HIV do, in fact, face a higher risk of bone fractures, notably at “fragility” sites—the spine (vertebrae), the hip and the wrist—than age-matched individuals in the general population.

Young's group analyzed data from 5,826 active HIV-positive participants in the HIV Outpatient Study (HOPS), who were followed from 2000 and 2008 and compared them with a standard sample from the general population, who were followed through the National Hospital Ambulatory Medical Care Survey between 2000 and 2006. Data from this analysis was originally reported at the 17th Conference on Retroviruses and Opportunistic Infections, held in San Francisco in February 2010.

The average age of those in the HOPS cohort was 40, and most were men. Just over half were white, and roughly three quarters had taken antiretroviral (ARV) therapy. In all, 233 people in HOPS had a new fracture between 2000 and 2008. The rates of new fractures substantially increased between 2000 and 2008, with the greatest increase occurring between 2000 and 2002.

Overall, Young and his colleagues found that people in the HOPS cohort were far more likely to have a bone fracture than HIV-negative people in the general population for every year within the study. When analyzed by gender, HIV-positive men had significantly higher rates than HIV-negative men, but this was not the case for HIV-positive women.

Fragility fractures, which are most strongly associated with low bone density, and which occur during normal activities or from a fall from body height or lower, were also much higher in HIV-positive people compared with their HIV-negative counterparts. Fragility fractures are a particular concern because people with such fractures tend to recover more slowly and to have more serious complications as a result of them than people with fractures not so closely tied to low bone density.

Young's team found that several factors were strongly associated with an increased risk for bone fracture. These included a history of substance abuse, HCV coinfection, concurrent diabetes, being older than 47 and having a lowest-ever CD4 count under 200. For fragility fractures, every 10-year increase in age brought a 43 percent increased risk of fracture, HCV infection doubled the risk and being significantly underweight increased the risk nearly fourfold.

“In light of this finding and the established relationship between low BMD and increased fracture risk in the general adult population, we recommend that screening for and correcting reversible causes of low BMD and fall risk be incorporated into routine clinical care of HIV-infected patients,” the authors conclude.