Lipid disorders in patients with HIV-induced diseases

Lipid disorders in patients with HIV-induced diseases circle Before the availability of protease inhibitors, elevated triglycericle levels were frequently observed in patients with advanced-stage HIV infection. circle Since the addition of protease inhibitors to combination treatments, metabolic side effects (alterations in distribution of adipose tissue and metabolic disorders combining dyslipidemia, insulin-resistance and glucose intolerance) have been observed in HIV-positive patients receiving these treatments. circle Reverse transcriptase nucleoside inhibitors also provoke metabolic disorders. Dyslipidemia is defined by an increase in triglycericle levels of varying and sometimes major intensity; either isolated or combined with a more moderate increase in LDL-cholesterol, while HDL-cholesterol levels may decrease or remain unchanged. circle These metabolic alterations are potentially atherogenic and may explain these patients' increased risk of cardiovascular disorders. Their mechanism is complex and not yet clearly elucidated. circle The infection, the improvement in patients' general health and immune status, and individual predisposing factors are probably involved. circle Treatment probably plays a major role, since the different drugs in these two classes show effects of clearly different intensity. In vitro and ex vivo studies suggest that protease inhibitors alter adipocyte differentiation and induce insulin resistance. Reverse transcriptase nucleoside inhibitors modify adipocyte metabolism too, promoting tissue atrophy. Endocrine factors (cortisol and growth hormones) are also likely to have a role in this hypertrophy of adipose, especially visceral, tissue. circle These metabolic abnormalities result mainly from the effects of the antiretroviral drugs, notably protease inhibitors, on the hepatic lipid metabolism and on tissue sensitivity to insulin. Lipodystrophy contributes to these abnormalities, as does the reduction in cytokine secretion by adipose tissue. circle Management of these metabolic disorders is based primarily on a change in the drug regimen (administration of the least deleterious combinations), followed by standard dietary measures and, when necessary, lipid-lowering agents.