Antiretroviral-therapy-associated lipoatrophy: current status and future directions

Lipoatrophy is perhaps the most visibly recognisable component of antiretroviral-therapy-associated lipodystrophy due to the rarity of this form of body composition change in the general population. In this respect, it is apparent that lipoatrophy represents a form of drug toxicity specifically involving the subcutaneous fat tissue, resulting in pathological fat loss that preferentially affects the limbs and face. It is now clear that the choice and duration of nucleoside analogue reverse transcriptase inhibitor (NRTI) therapy (stavudine > zidovudine) is the dominant risk factor for clinical lipoatrophy, as well as for the pathological changes to adipose tissue that underlie the clinical syndrome. Host factors have also emerged as important modulators of lipoatrophy severity in patients receiving these NRTI drugs, including age, racial origin, and severity of immune deficiency. On the other hand, the use of selected HIV protease inhibitor drugs is more closely associated with metabolic complications such as dyslipidemia and insulin resistance and has not been convincingly linked to lipoatrophy. This review examines the clinical and pathological manifestations of lipoatrophy, and also presents information regarding the safety profile of alternative NRTI drugs, such as tenofovir and abacavir, that have not been associated with lipoatrophy risk. With increasing knowledge of lipoatrophy pathogenesis, it is likely that moderate and severe forms of this complication can now be considered a preventable complication of HIV treatment. However, it is also important to recognise that there is an ongoing burden of disease in patients who have been affected by lipoatrophy over the past six years, and that therapeutic management of established lipoatrophy will remain a challenge into the future.