Heroin use, AIDS, predict reduced bone mineral density in older men with HIV

Older HIV-positive men have lower bone mineral density than their HIV-negative peers, a US study published in the online edition of AIDS shows. The study population involved men with, or at risk of, HIV who were aged over 49. Advanced HIV disease and heroin use were associated with bone loss monitored during follow-up.

“Heroin users with AIDS may be at particular risk of bone loss,” comment the investigators.

The proportion of HIV infections involving older adults is increasing. There is currently uncertainty if those living with HIV will be at greater risk of developing diseases associated with ageing, such as bone loss.

Older patients with HIV, or at risk of the infection because of injecting drug use, have a number of risk factors for bone loss including low body weight, low testosterone levels, smoking, alcoholism and poor nutrition.

Because of this high burden of risk factors, investigators from the Cohort of HIV-at Risk Aging Men’s Prospective Study (CHAMPS) monitored changes and predictors of bone density in a cohort of 389 men, 230 of whom were HIV-positive.

These men were recruited between 2002 and 2003. The HIV-negative participants were at risk of infection with HIV via injecting drug use or high-risk sexual behaviour.

On entry to the study the men underwent a DEXA scan to determine bone mineral density in three sites: total hip; femoral neck; and lumbar spine. This test was repeated a minimum of 18 months later.

At the time of the first scan, the patients had a mean age of 56 years. Mean body mass index (BMI) at this time was 26.6kg/m² and was significantly higher in HIV-negative individuals (p = 0.001). Over half (54%) of those with HIV had been living with the infection for over ten years and 42% had been diagnosed with AIDS. Median CD4 cell count for the HIV-positive patients was 389 cells/mm³.

There was a high prevalence of risk factors for bone loss: 88% had a lifetime history of cocaine or heroin use; 64% smoked; 47% were alcoholics; and 47% had low testosterone.

At the time of the first scan, HIV-positive men had lower bone density at the femoral neck (p = 0.02), total hip (p < 0.01), and lumbar spine (p = 0.03), when compared to the HIV-negative controls.

The men had their second scan after a mean interval of 32 months. Once again, HIV-positive men had lower bone mineral density at all three sites than those who were HIV-negative (femoral neck, p = 0.03; total hip, p = 0.02; lumbar spine, p = 0.02).

When the first scan was performed, 46% of men had normal bone mineral density at all three sites, 41% had osteopenia (low bone mineral density) and 12% had osteoporosis (thinning of the bones).

During follow-up, 13% of those with normal bone mineral density at baseline developed osteopenia. Incidence of this disease progression was higher amongst men with HIV (7.2 per 100 person years vs 2.6 per 100 person years).

A total of 12% of men who initially had osteopenia developed osteoporosis. Incidence was comparable for those with and without HIV (2.2 per 100 person years).

Bone loss at all three sites was associated with an AIDS diagnosis and heroin use (both p = 0.04). Infection with hepatitis C was associated with loss of bone density in the femoral neck (p = 0.04).

“An improved understanding of factors associated with ongoing bone loss and fracture risk is needed to help guide thresholds for assessment of bone mineral density and for osteopenia treatment in HIV-infected persons and opioid users,” comment the investigators, adding: “The degree to which opioid use and advanced HIV disease affect the risk of osteopenia will inform the need for treatment efforts and programs to prevent bone loss among drug users and those with HIV infection.”