Trabecular bone deficits predominate in the appendicular skeleton of midlife women living with HIV: findings from a cross-sectional study in Zimbabwe

HIV-related mortality has fallen due to the scale-up of antiretroviral therapy (ART), so more women living with HIV (WLH) now live to reach menopause. Menopausal estrogen loss causes bone loss, as do HIV and certain ART regimens. However, quantitative bone data from WLH are few in Africa. A cross-sectional study of women aged 40-60 yr (49% WLH) was conducted in Harare, Zimbabwe. Menopause status, fracture history, HIV status and treatment, and anthropometry were collected, and radial/tibial peripheral QCT (pQCT) scans were performed. pQCT outcomes were distal radius and tibia trabecular volumetric BMD (vBMD), total area, and compressive bone strength (BSIc); proximal radius and tibia cortical vBMD, BMC, cortical thickness, bone area, and stress-strain index (SSI). Linear regression determined differences by HIV status, minimally adjusted for age and menopause status, and further adjusted for height and fat mass. Relationships between pQCT parameters and major osteoporotic fracture history were explored using univariate logistic regression. In WLH, linear regression assessed associations between HIV and ART durations on pQCT measures. 384 women mean (SD) age 49.7 (5.8) yr had pQCT data. WLH had lower absolute pQCT measures at all sites. Overall, HIV-related deficits were robust to adjustment for age, menopause status, height, and fat mass: WLH had lower trabecular vBMD (radius -7.3 [-12.5; -2.0]%, tibia -5.4 [-9.1; -1.7]%), and cortical vBMD (radius -3.5 [-5.9; -1.1]%, tibia -1.1 [-1.6; -0.5]%). Strength estimates were lower in WLH and of similar magnitude at the radius and tibia. Longer HIV duration was associated with lower radius bone area, BMC, and estimates of bone strength, independent of ART duration. Trabecular deficits predominate in WLH, though with age cortical compartment bone loss may increase in importance. This is particularly concerning as these differences were observed at the radius, a common site of postmenopausal osteoporotic fracture. Improved access to treatment for HIV now means women with HIV (WLH) can live well into older adulthood; however, this puts them at risk of age-related diseases, such as osteoporosis. HIV and some of its treatments are known to cause bone loss, as does menopause, which may result in increased bone fragility (fractures). However, studies on osteoporosis and fracture risk are scarce in southern Africa, where most people with HIV live. In this study in Zimbabwe, we used 3D bone imaging at the forearm (radius) and lower leg (tibia) to describe differences in bone density and structure between WLH and women without HIV. We found that WLH had lower values at the arm and leg, where differences in trabecular bone density were more than 5%. Estimates of radius and tibia bone strength were lower in WLH. Longer HIV duration was associated with a smaller radial bone area with less mineral and lower estimated strength. Our findings highlight that at mid-life, WLH have less bone and lower trabecular bone strength than their peers, though with age, cortical compartment bone loss may increase in importance. This greater bone loss may lead to increased fracture risk earlier in life in WLH.