Evaluating Bone Microarchitecture and Strength in Women With HIV

In addition to lower bone mineral density (BMD), both bone microarchitecture and strength are reduced in women living with HIV (WLWH), even after accounting for known risk factors for osteoporosis, according to study results published in Bone.

Most prior research has used dual-energy x-ray absorptiometry to assess bone health in WLWH, and therefore limited data are available from imaging tools that can quantify trabecular and cortical BMD, bone structure, and bone strength, such as peripheral quantitative computed tomography (pQCT) and high-resolution pQCT (HR-pQCT).

The goal of the current study was to assess and compare these 3-dimensional bone measures between WLWH and control individuals without HIV. In addition, the researchers investigated how HIV-related factors affected bone outcomes.

Data from the Children and Women: Antiretrovirals and Markers of Aging bone health substudy (CARMA-OSTEO) were used for the current cross-sectional study. Bone microarchitecture and strength and BMD were compared between 50 WLWH (mean age, 50.4 years; 44% postmenopausal) and 50 control women (mean age, 51.8 years; 52% postmenopausal).

Dual-energy x-ray absorptiometry was used to assess areal BMD at the lumbar spine, total hip, and femoral neck; HR-pQCT was used to assess distal radius and tibia trabecular BMD, thickness, and number, as well as cortical BMD and area. The researchers also applied finite element analysis to HR-pQCT images to assess bone strength.

Baseline characteristics were similar in WLWH and control women, including age, ethnicity, reproductive status, and lifetime fragility fractures. History of systemic steroid treatment was reported in 2 WLWH. All WLWH except for 1 were treated with combined antiretroviral therapy and most (80%) had undetectable HIV plasma viral load.

In younger women (aged <50 years), there was no difference in areal BMD z scores at the various skeletal sites between WLWH and control women. In older women (≥50 years), areal BMD T-scores at the total hip and femoral neck were significantly lower in WLWH compared with control women. Distal radius trabecular BMD, thickness, and number as well as failure load were significantly lower in WLWH in an unadjusted analysis, but after adjustment for covariates, only trabecular BMD and thickness remained significantly lower compared with the control group. In a similar fashion, distal tibia trabecular BMD and failure load were significantly lower in WLWH than in control women in the adjusted analysis.

A history of previous tenofovir treatment was associated with a significantly lower total hip BMD z score (P =.044) in younger WLWH, as well as lower lumbar spine T-score, distal radius trabecular BMD, and trabecular number among WLWH aged ≥50 years. In addition, in older women, current tenofovir treatment was associated with a lower lumbar spine T-score compared with treatment-naive patients (P =.004).

Among WLWH aged ≥50 years, but not in younger women, there was a positive association between years since HIV diagnosis and total hip T-score.

The study had several limitations, including the cross-sectional design, relatively small sample size, missing data on serum vitamin D levels and whole body measures of lean and fat mass, and inability to complete diagnostic serology in control individuals to assess hepatitis C virus status.

“[H]ealthcare providers should be aware of increased risk for osteoporosis and fragility fractures in WLWH, starting as early as age [40 years], and consider primary prevention strategies that have proven effective in the general population alongside HIV care,” concluded the researchers.

Reference

Macdonald HM, Maan EJ, Berger C, et al. Deficits in bone strength, density and microarchitecture in women living with HIV: a cross-sectional HR-pQCT study [published online June 26, 2020]. Bone. doi:10.1016/j.bone.2020.115509