Menopause, race/ethnicity and changes in bone density

As people age, bones tend to become thinner and more prone to fractures. Researchers have found that HIV-positive people are generally at an increased risk for thinning bones and fractures.

Among women who have transitioned through menopause, major shifts in the production of hormones—estrogen and progesterone—have occurred. While these shifts affect fertility, they also affect bones.

Scientists in New York City have been conducting research called the Menopause Study (MS). Just over a decade ago they enrolled women, about half of whom were HIV-positive, and have been monitoring changes to their hormones and health. Participants underwent twice-yearly interviews, physical examinations, blood tests and other assessments. A subset of women had low-dose X-ray scans called DEXA (dual-energy X-ray absorptiometry), which are used to assess bone density. The latest analysis from MS focused on the complex relationship between race/ethnicity, stages of menopause and bone density.

Study details

Researchers analysed data from 219 HIV-negative and 246 HIV-positive women who began to enter the study in 2001. All of these women had two DEXA scans while in the study—one at the beginning of the study and the other at least 18 months later. This allowed researchers to assess changes in bone density over time.

The average profile of HIV-positive participants upon entering the study was as follows:

• age – 47 years
• body mass index (BMI) – 28
• CD4+ count – 486 cells/mm³
• HIV viral load – 141 copies/mL
• taking anti-HIV therapy – 70%
• history of AIDS – 31%
• current smoker – 61%
• ever used opioids – 31%
• hepatitis C virus positive – 52%
• nearly all of the women were deficient in vitamin D

At study entry, almost 20% of all women had transitioned through menopause; that is, they were postmenopausal. Over the course of the study, an additional 10% of HIV-positive women and 6% of HIV-negative women became postmenopausal.

Results—Comparisons by HIV status

After an average of five years in the study, DEXA scans revealed that in general HIV-positive women had reduced bone density in their hips and thighs compared to HIV-negative women.

A note on terms

Researchers who study menopause have divided this process/event into several stages as follows:

• premenopause – menopause has not yet began
• perimenopause – the early stage of menopause, when periods become irregular and may become shorter or longer. Some women also experience symptoms such as problems sleeping, hot flashes and vaginal dryness. Perimenopause usually occurs when women are in their 40s.
• menopause – eventually periods stop and when a woman has not had her period for 12 consecutive months, menopause has occurred. Symptoms such as hot flashes, sleeping problems, decreased energy and, in some women, feelings of anxiety and sadness can occur. Other issues associated with menopause can include dry skin, thinner hair and weight gain. The transition through the stages of menopause can last several years.
• postmenopause – menopause is finished

Results—Stage of menopause and bone loss

When researchers examined the overall impact of changes in bone density and menopausal stage they found the following:

• Women who entered the study while in perimenopause and then became postmenopausal had the greatest decrease in bone density, averaging about 1.7% per year.
• Women who were postmenopausal throughout the study had their bone density decrease by an average of 1% per year.
• Women who were premenopausal when they entered the study and who became perimenopausal and remained in perimenopause throughout the study had their bone density decrease by 0.64%.
• Women who were perimenopausal when they entered the study and remained in perimenopause throughout the study had their bone density decrease by about 0.60%.

A look at race/ethnicity and HIV

Overall, the researchers found that HIV did not accelerate bone thinning among women who were black.

However, among women who were white or Latina, HIV infection was associated with a 0.6% decreased bone density per year in the hips.

Black women and changes in bone density during the menopause transition

All black women in the study, regardless of HIV status, experienced greater loss of bone density in the hips during the menopause transition than women of other ethno-racial groups. Among all black women, here are some changes in bone density depending on the stage of menopause with which they entered and ended the study:

• perimenopause to postmenopause – a decrease of 1.9% in bone density occurred
• postmenopausal throughout the study – a decrease of 1.3% occurred
• premenopause to perimenopause – a decrease of 1% occurred
• perimenopausal throughout the study – a decrease of 0.76% occurred

ART

Starting anti-HIV therapy (commonly referred to as ART or HAART) was not linked to a decrease in bone density. However, the researchers found that interrupting ART and then restarting it was linked to decreased bone density at the thigh.

Use of the anti-HIV drug tenofovir (Viread and found in Truvada, Atripla, Complera and Stribild) was not directly linked to the loss of bone density. However, when participants stopped taking tenofovir, the density of their bones at the thigh and spine increased.

We caution readers that this study was observational in nature so firm conclusions about the impact of tenofovir on bone health cannot be drawn. Furthermore, the reasons for the discontinuation of tenofovir were not reported; these could have affected the interpretation of the data.

Bear in mind

These findings about the stage of menopause and different ethno-racial groups shed new light on bone thinning in women. According to the researchers, the results of the MS study can help doctors and nurses caring for HIV-positive women. By taking factors such as HIV infection into account for non-black women and the stage of menopause for black women, doctors may be able to identify women at the greatest risk for bone thinning (and therefore fracture risk) and prioritize patients for discussions about the initiation of screening and the offer of treatment for low bone density.

—Sean R. Hosein

REFERENCE:

Sharma A, Flom PL, Rosen CJ, et al. Racial differences in bone loss and relation to menopause among HIV-infected and uninfected women. Bone. 2015 Aug;77:24-30.