Ramalho J, Martins CSW, Galvão J, et al. - In young men living with HIV before (n = 20) and 12 months after (n = 16) initiating tenofovir disoproxil fumarate (TDF)/lamivudine/efavirenz, researchers assessed change in BMD via dual-energy X-ray absorptiometry (DXA) and bone histomorphometry by tetracycline double-labeled transiliac crest biopsies. Associations were investigated between calciotropic hormones, urinary phosphate excretion, pro-inflammatory and pro-resorptive cytokines, and bone remodeling-related proteins with changes in BMD and histomorphometry. According to results, no significant worsening of renal phosphate excretion or mineralization parameters was observed. Increases in PTH were associated with reduced BMD but not histomorphometric parameters. Overall, these data indicate bone formation and mineralization abnormalities with HIV infection, and were apparent in the early stages. Overall, there was an increase in bone remodeling with TDF-containing antiretroviral therapy, reflected by increased osteoblast and osteoclast surfaces, but persistence in mineralization defect, resulting in increased osteoid volume.