Low bone mineral density a risk for HIV-positive women in middle age

HIV-positive women entering the menopause are significantly more likely to have osteopenia (low bone mineral density) than comparable HIV-negative women, an American study published in the April 1^st edition of Clinical Infectious Diseases has found.

The use of antiretroviral drugs was not, however, associated with the development of osteopenia.

Thanks to effective anti-HIV therapy many people with HIV are living longer, healthier lives. As a result more HIV-positive women are surviving into menopause, which is often accompanied by loss of bone density and mass.

Although the risk of bone problems during menopause are largely determined by genetic and factors, HIV-positive women can have several factors which increase their risk of osteopenia, such as the inflammatory effects of HIV, disrupted hormone production, and increased levels of cigarette smoking and drug use, and several studies have found that HIV-positive individuals do have decreased bone mineral density.

To better understand the effect of HIV infection on bone density, investigators from the US Menopause Study compared middle-aged HIV-positive and HIV-negative women with similar demographics and lifestyle characteristics. They also examined whether the use of antiretroviral drugs was associated with changes in bone mineral density.

A total of 495 women were recruited to the study in large US urban areas between 2001 and 2003. The aim was enroll a cohort of middle-aged women comprising 50% HIV-positive women, 50% HIV-negative women and 50% of women who were current or past opiate users or who had a partner who used the drug.

Blood samples were collected from the women twice a year and they were interviewed about their medical history, use of prescription medication (including antiretrovirals), drug use habits, and exercise patterns.

Shortly after recruitment to the study all the women had a DEXA scan to determine their bone mineral density in the hip and lumbar spine regions.

The median age was 44. The majority of women (54%) were black, and 53% were HIV-positive. Compared to HIV-negative women, they were significantly more likely to be black and unemployed, but less likely to be current cigarette smokers, depressed or over-weight. A total of 44% of HIV-positive women had been diagnosed with the infection for ten years or more and 78% were taking antiretroviral therapy.

Risk factors low bone mineral density were common in both HIV-positive and HIV-negative women: 91% were current or former smokers, 58% were depressed, and 75% had some history of opiate use. However, low weight was uncommon, and even amongst HIV-positive women, only a third were categorised as having a weight that was lean-to-normal.

Both hip (p = 0.01) and lumbar spine (p = 0.04) bone mineral density was reduced in women with HIV compared to HIV-negative women. In multivariate analysis the investigators found that HIV infection (p < 0.01), older age (p < 0.01), non-black race (p < 0 .001), lower body weight (p < 0.01), estrogen use (p = 0.04), a past history of bone fractures (p = 0.05) and methadone treatment (p < 0.01) were all significantly associated with osteopenia across the cohort.

In further analysis, restricted to black women, the investigators found that HIV infection was not associated with osteopenia, but that age (p < 0.001), weight (p <0.01), methadone treatment (p = 0.03) and use of prednisone (p < 0.01).

Amongst HIV-positive women, overall, the use of antiretrovirals had no association with osteopenia. Nor did the investigators find any association with reduced bone mineral density with protease inhibitor use or the use of any other class of anti-HIV drug.

“We found lower bone mineral density among middle-aged women with HIV infection than among women with similar behavioural risk factors without HIV infection”, write the investigators, who note that their study had several methodological strengths, not least its size and its ability to compare HIV-positive and uninfected women with similar characteristics. However, they do acknowledge limitations with their study, particularly its cross sectional design and the lack of data concerning hormone levels. This limitation was also highlighted by an accompanying editorial.

The investigators conclude HIV-positive women “entering the menopause… should be screened for osteopenia, and calcium and vitamin D therapy should be considered for middle-aged women with HIV infection and opium dependence.” The editorial concludes with a call for more longitudinal studies into the subject.