The role of HIV and antiretroviral therapy in bone disease.

Current knowledge suggests that both HIV and antiretroviral drugs are likely to contribute to bone disorders in patients with HIV infection. This article includes a review and update on the part played by the virus and the drugs in the low bone mineral density of HIV-infected patients, and a discussion about their implications in clinical practice. HIV viral proteins may affect osteoblast and osteoclast function, and many clinical studies have shown that during antiretroviral therapy, especially at the beginning, there is an accelerated bone mineral loss associated with bone resorption markers, which may be of differing intensity depending on the HIV drugs used. Vitamin D insufficiency/deficiency is highly prevalent and in some investigations it has been associated with antiretroviral therapy, more often with regimens based on efavirenz. Recent data suggest that immune reconstitution may play a major role in early antiretroviral therapy-related bone loss. Given the complex interaction between HIV and drugs in causing low bone mineral density, optimization of antiretroviral therapy and preemptive strategies aimed to prevent bone loss during therapy may be of paramount importance.