TreatmentUpdate
209

June/July 2015 

Investigating fracture risk in women with and without HIV

To better understand health issues among women at high risk for or who have HIV, researchers at clinics in key cities in the U.S. have collaborated on a study called WIHS (Women’s Interagency HIV Study, pronounced “wise”). This study is important because it has enrolled women who are from the same general community with a similar socio-economic profile. Its findings are highly relevant to the HIV epidemic among women in the U.S. and perhaps some other high-income countries as well. A recent analysis from WIHS sought to understand health-related information collected with a particular focus on fractures. Over an average of 10 years of monitoring, the researchers found that HIV-positive women were more likely to develop fractures than HIV-negative women. Possible factors associated with an increased risk for fractures were also analysed.

Study details

Researchers analysed data collected between 2002 and 2013. This information was obtained from twice-yearly interviews, medical examinations, blood tests and other assessments. In total, data from 1,713 HIV-positive and 662 HIV-negative women were analysed. Our report focuses on the HIV-positive women.

Recruitment for the study occurred at clinics in the following cities:

  • The Bronx/Manhattan
  • Brooklyn
  • Chicago
  • Los Angeles
  • San Francisco
  • Washington, DC

Upon entering the study, the average profile of HIV-positive participants was as follows:

  • age – 40 years
  • body mass index (BMI) – 29
  • current smoker – 45%
  • underwent or undergoing menopause – 19%
  • history of injecting street drugs – 28%
  • history of fracture(s) – 4%
  • a moderate or worse degree of kidney disease – 8%
  • CD4+ count – 480 cells/mm3
  • history of AIDS-related illness – 40%
  • taking potent combination anti-HIV therapy (ART) – 63%
  • active hepatitis C virus infection – 24%

Results—New fractures

During the study a total of 360 women (16%) developed fractures, distributed as follows:

  • HIV-positive women – 18%
  • HIV-negative women – 14%

This difference was statistically significant; that is, not likely due to chance alone.

Fragility fractures—fractures that can occur because of falls from standing height (as opposed to major trauma such as car accidents)—occurred in 4% of all women and were distributed as follows:

  • HIV-positive women – 5%
  • HIV-negative women – 4%

This difference was not statistically significant.

Here is some additional information about the women at the time new fractures occurred:

Average age

  • HIV-positive women – 42 years
  • HIV-negative women – 40 years

Proportion who had completed the transition through menopause

  • HIV-positive women – 57%
  • HIV-negative women – 47%

None of these differences was statistically significant.

Compared to HIV-negative women, HIV-positive women were more likely to have fractures in the hips.

Also, HIV-positive women were more likely to have fragility fractures in parts of the body not commonly associated with these fractures, such as the following:

  • foot
  • toe
  • hand
  • finger
  • ankle
  • knee

Linked to fractures

Taking all the data they collected into account, the researchers found that the presence of HIV infection raised the risk of developing a fracture by 45%.

Other factors linked to an increased risk for fractures were as follows:

  • older age
  • being white
  • history of fracture(s) prior to entering the study
  • history of substance use
  • history of using cocaine

Strengths and weaknesses

This analysis of data captured over a decade was particularly useful because, unlike some other studies, WIHS enrolled HIV-positive and HIV-negative women from the same communities. This is important because many studies tend to compare HIV-positive people from an idealized average HIV-negative person, not necessarily from the same geographic and socio-economic group.

Furthermore, although there have been many studies of bone density in HIV-positive people, such studies have enrolled mostly men. Despite this, WIHS found that rates of fracture in HIV-positive women were similar to those found in a study among Danish HIV-positive men.

There are limitations to WIHS. A major one was that researchers were unable to distinguish the impact on bone health of co-infection with hepatitis C virus from that of substance use. Another limitation was that reports of fractures by participants were not confirmed with additional X-rays or verified in medical records.

What to expect

Based on the WIHS results, doctors associated with the study stated that they expect fracture rates “will increase over time in [HIV-positive] women as they age. In particular, rates may increase among women [who are not black] and in women with a history of substance use.”

The results from WIHS confirm findings from other studies about an increased fracture risk among women with HIV, even among women who are merely middle-aged.

The WIHS findings underscore the importance of efforts by doctors and nurses to screen and treat HIV-positive women for low bone density.

—Sean R. Hosein

REFERENCE:

Sharma A, Shi Q, Hoover DR, et al. Increased fracture incidence in middle-aged HIV-infected and uninfected women: updated results from the Women’s Interagency HIV Study. Journal of Acquired Immune Deficiency Syndromes. 2015; in press.