Bone mineral status unaffected by HIV in South African women

HIV infection had no discernible effect on bone mineral status in black South African women over the course of 1 year, study data showed. Researchers noted, however, that clinicians should be aware of potential bone loss linked with antiretroviral therapy.

“HIV and [antiretroviral therapy (ART)] have both been associated with bone loss and increased risk of fracture. Evidence is mixed, but the general consensus is that ART-exposure, particularly to tenofovir disoproxil fumarate, is associated with bone loss,” Matthew M. Hamill, of the South African Medical Research Council and Elsie Widdowson Laboratory, Cambridge, UK, and colleagues wrote. “To date, available data about the possible effects of HIV infection on bone health and vitamin D status are heavily biased towards Caucasian males in resource-rich societies who have a much lower lifetime risk of osteoporotic fracture than women. The effects of HIV and ART on bone health and vitamin D status in sub-Saharan Africa, where the burden of HIV infection lies, and where osteoporotic fracture rates are predicted to rise, are largely unstudied and, although data are emerging, there are important gaps and an urgent need for targeted research.”

The researchers studied changes in body composition, vitamin D status, bone mineral metabolism and changes in bone mineral density among 247 premenopausal black women from Soweto, South Africa. DXA scanning, anthropometry and blood and urine collections were performed at baseline and again at 12 months among 187 participants.

Sixty-seven women were HIV-negative through the entire study, 60 were HIV-positive with preserved CD4 counts at baseline, and 60 were HIV-positive with low CD4 counts at baseline, making them eligible for ART.

All patients were ART-naive. By the 12-month mark, 51 of the women with low CD4 counts had begun ART, with more than 85% receiving tenofovir disoproxil fumarate, lamivudine and efavirenz.

After 1 year, the low-CD4 group and the HIV-negative group experienced increases in body weight and fat mass, while those with preserved CD4 counts did not (group-by-timepoint P ≤ .001, P = .002, respectively), Hamill and colleagues reported. The low-CD4 group saw significant decreases in areal BMD (2% to 3%) at the femoral neck (P ≤ .002) and lumbar spine (P ≤ .001). Researchers wrote that these decreases were associated with increased bone turnover, but they reported no significant changes in vitamin D status, renal phosphate handling or serum phosphate concentrations. Hamill and colleagues wrote that the bone loss in the low-CD4 group appeared related to ART.

“This study suggests that, in urban, black South African women, HIV infection per se has no discernible effects on bone mineral status over a 12-month period but that exposure to TDF-based ART is associated with loss of bone mineral and an increase in bone turnover,” the researchers wrote. “Given that TDF is currently part of first-line ART in many African nations and other low- and middle-income countries, there is a need to develop better awareness among clinicians of possible bone mineral density, and to ascertain whether such bone loss is progressive with longer duration of ART exposure, ultimately resulting in osteoporosis and increased fracture risk.” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosures.