Protease inhibitors

Lipodystrophy became apparent in the HIV-positive population within eighteen months of the widespread adoption of protease inhibitor (PI) treatment, and was initially attributed to PI use. However, although an association between protease inhibitor treatment and body fat changes has been identified repeatedly in studies, this does not necessarily mean that protease inhibitors are responsible for the syndrome, or that they are its sole cause .

Much of the research into lipodystrophy has been retrospective: many of the analyses may simply reflect which drugs were more commonly taken at that time. For example, d4T and indinavir have been associated with lipodystrophy more frequently than other drugs, but this may be a consequence of the more frequent prescription of indinavir and d4T to treatment-experienced patients with advanced HIV disease after 1996. Prospective studies are needed to investigate the relationship between particular drugs and body fat changes in an unbiased manner.

The type and duration of antiretroviral therapy may be an important factor in determining what type of body fat and metabolic disorders an individual may experience. For example, various studies have found ritonavir, indinavir and saquinavir are associated with lipodystrophy. Indinavir has, in fact, been particularly linked to abdominal fat accumulation. ¹