Changes in Bone Mineral Density, Body Composition, Vitamin D Status, and Mineral Metabolism in Urban HIV-Positive South African Women Over 12 Months

Human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are associated with bone loss and poor vitamin D status in white populations, though their relative roles are not known. No previous studies have examined longitudinal changes in areal bone mineral density (aBMD), measured by dual-energy X-ray absorptiometry (DXA), or in vitamin D status in HIV-positive African women. Of 247 premenopausal, urban, black African women from Soweto, South Africa, initially recruited, 187 underwent anthropometry, DXA scanning and blood and urine collections at both baseline and 12 months. Of these, 67 were HIV-negative throughout (Nref), 60 were HIV-positive with preserved CD4 counts at baseline (Ppres), and 60 were HIV-positive with low CD4 counts at baseline, eligible for ART by South African standards of care at the time (Plow). No participant had been exposed to ART at baseline. By 12 months, 51 Plow women had initiated ART, >85% of whom took combined tenofovir disoproxil fumarate (TDF), lamivudine, and efavirenz. By 12 months, Plow and Nref, but not Ppres, increased in body weight and fat mass (group-by-timepoint p ≤ 0.001, p = 0.002, respectively). Plow had significant decreases in aBMD of 2% to 3%, before and after size adjustment, at the femoral neck (p ≤ 0.002) and lumbar spine (p ≤ 0.001), despite significant weight gain. These decreases were associated with increased bone turnover but there were no significant differences or changes over time in vitamin D status, serum phosphate concentrations, or renal phosphate handling. Excluding data from nine Plow women unexposed to ART and 11 Ppres women who had initiated ART accentuated these findings, suggesting the bone loss in Plow was related to ART exposure. This is the first study describing DXA-defined bone loss in HIV-positive Sub-Saharan African women in association with ART. Further work is required to establish if bone loss continues with ongoing ART and, if so, whether this results in increased fracture rates.