Metabolic syndrome in HIV-infected individuals: underlying mechanisms and epidemiological aspects

The success of highly active antiretroviral therapy (HAART) has determined a dramatic decline in AIDS-and immunodeficiency-related causes of death in the HIV-infected population. As life-expectancy increases, such individuals have become gradually exposed not only to the effects of aging itself, but also to the influence of environmental risk factors, which are known to act in the general population. These features can lead to obesity, diabetes mellitus and ultimately cardiovascular diseases (CVD). Metabolic complications and abnormal fat distribution were frequently observed after a few years of antiretroviral therapy and, as the array of antiretroviral drugs became broader, long term metabolic alterations are becoming far more common worldwide. Nevertheless, the risk of not being on HAART is overwhelmingly greater than the metabolic adverse events in terms of morbidity and mortality events. HIV/HAART-induced metabolic unbalances overlap in some extent the components of Metabolic Syndrome (MetS) and its high rates in the HIV population place infected individuals in an elevated CVD risk category. MetS can explain at least in part the emergence of CVD as the major morbidity and mortality conditions in the HIV population. In this review we convey information on the underlying aspects of MetS during HIV infection, highlighting some physiopathological and epidemiological features of this comorbidity along with the role played by HIV itself and the synergy action of some antiretroviral drugs. Considerations on MetS management in the HIV population are also depicted.