Conference Coverage

Bone density slow to rebound after lactation in women with HIV



Women with HIV had more bone mobilization during lactation, and attenuated skeletal recovery after lactation, compared with HIV-negative women, according to research presented during the Conference on Retroviruses & Opportunistic Infections, which was presented online this year. CROI organizers chose to hold a virtual meeting because of concerns about the spread of COVID-19.

The study “demonstrated that there were reductions as expected in BMD during breastfeeding, and there was recovery at the end of breastfeeding, which was higher among women who were not HIV-infected compared to HIV-infected women,” said Mary Glenn Fowler, MD, speaking in a video presentation during the virtual conference. The differences between women who had HIV and the HIV-negative reference group were statistically significant (P = .003 for lumbar spine and P less than .001 for whole-body aBMD).

“We also saw that for whole-body BMD, there was recovery at the end of breastfeeding for women who were not HIV infected, but a dampened response of recovery for BMD for HIV-infected women,” she went on, adding: “These findings held after adjustment for parity, age, body mass, breastfeeding practices, duration of breastfeeding, use of [injectable medroxyprogesterone acetate], and resumption of menses.”

Dr. Fowler presented the study’s results on behalf of lead author Florence Nabwire, PhD, an investigator scientist in the nutrition and bone health group of the United Kingdom’s Medical Research Council (Cambridge).

Although it’s known that antiretroviral therapy (ART) is associated with bone loss, Dr. Fowler explained that there are only limited data in HIV-positive women who are lactating. It’s important to see what happens during lactation for this group of women because of the potential sequelae later in life of insufficient recovery from the physiological bone mobilization that occurs during lactation. The study looked at changes in areal bone mineral density (aBMD) both during and after lactation for women with HIV living in Uganda who were taking Option B+ ART, a regimen that includes tenofovir, 3TC, and efavirenz. These women were compared with a reference group of HIV-negative women.

In all, 95 women with HIV and 96 HIV negative women were recruited into the study during pregnancy. Participants were followed postpartum at weeks 2, 14, and 26, and at a final visit that occurred 14 weeks after lactation stopped.

In addition to lumbar spine, total hip, and femoral neck aBMD measurements, the investigators also obtained whole body-less-head reading.

For total hip and femoral neck aBMD, the nadir of density was seen at 26 postpartum, when a drop of about 6% was seen from baseline readings. By the final post-lactation visit, women without HIV had recovered to their baseline; for women with HIV, some recovery also occurred, but the effect was dampened, with a persistent bone density deficit of about 3% from baseline. The differences between HIV-positive and HIV-negative women in these measurements were also statistically significant, at P less than .001 for total hip aBMD differences and P = .0008 for femoral neck differences. Again, correction for multiple confounders didn’t attenuate the results, said Dr. Fowler.

“In conclusion, these data showed accentuated mobilization of hip and whole body aBMD during lactation,” said Dr. Fowler, who also noted “slower skeletal recovery post lactation for HIV-infected women.” Clinical implications of these findings aren’t currently known, she said. Further ongoing studies are aiming to tease out both mechanisms and longer-term consequences for the bone health of HIV-infected women and their children, who may also see differences in bone mineral accretion and growth.

Session moderator Risa Hoffman, MD, in introductory remarks, set the findings in some context. “As we know, HIV-positive adults have low bone mineral density, and this appears to be a result of interactions of HIV, traditional risk factors for loss of bone density, and antiretroviral therapy,” said Dr. Hoffman, director of the global health program at the University of California, Los Angeles. She added that previous work had shown that “middle-aged HIV-positive women have higher 10-year fracture incidence compared to their HIV-negative counterparts.” The current study, she said, “has both short- and long-term implications for women as they go through multiple pregnancies and multiple periods of breastfeeding.”

The study was funded by the United Kingdom’s Medical Research Council and Department for International Development as well as the Alborada Trust and the Gates Cambridge Scholarship. The authors reported no conflicts of interest.

SOURCE: Nabwire F et al. CROI 2020, Abstract 768.

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