[Multifactorial relations between HIV, HAART and bone metabolism]

Today, there is reasonable agreement about the frequent association between osteopenia/osteoporosis and HIV infection. Opinions about the aetiopathogenesis of osteopenia and osteoporosis during HIV infection are really divergent. Some authors suggest that bone dysmetabolism is related to the HIV infection itself. The loss of bone mineral density (BMD) occurs in two-thirds of HIV-1-seropositive individuals naive to antiretroviral therapy (ART), and improves during the follow-up of patients receiving ART, independently from the drug class used. Moreover, a reduced BMD has also been associated with both ART-induced lipodystrophy and mitochondrial toxicity. Several authors have observed an association between HAART and osteoporosis; however, methodological bias, particularly the lack of control groups, could have obscured the data. Today, the role of HAART on bone metabolism and on BMD in HIV-seropositive patients is still controversial. The available data on BMD studies after the introduction of HAART are much more contradictory than those from before this era. The variety and complexity of changes in bone metabolism in patients with HIV infection and the different pathomechanisms leading to changes in bone mass, as well as the different stages of disease at the time of clinical investigation, may contribute to the contradictory data on BMD measurements in HIV-infected patients after HAART.