What Causes Lipodystrophy?

What Causes Lipodystrophy?

Scientists have many theories about what causes lipodystrophy and research in this area is ongoing. However, the exact causes of lipodystrophy are still unknown. There may be different causes for different symptoms.

• Fat loss: Research shows that certain HIV drugs from the nucleoside reverse transcriptase inhibitor (NRTI) class are the main cause of fat loss. These drugs are Retrovir (zidovudine, AZT) and Zerit (stavudine, d4T)
• Fat gain: It is less clear what causes fat gain. Taking protease inhibitors (PIs), another class of HIV drug, may increase the risk of fat accumulation. Another theory is that insulin resistance and increased lipid levels play a role in fat gain
• Increased lipids: Some of the PIs are believed to increase lipid levels. It is still not clear which ones are most likely to do this, but Reyataz (atazanavir) seems to be the least likely to cause increased lipid levels
• Increased glucose levels, insulin resistance, and diabetes: Both PIs and NRTIs have been linked with insulin resistance and diabetes
• Lactic acidosis: Some of the NRTIs are associated with lactic acidosis, especially Zerit and Videx (didanosine, ddI).

Not everyone taking HIV drugs develops body shape changes or problems with fat or sugar levels in the blood. Researchers have been looking for other factors that may cause lipodystrophy. The following appear to be risk factors:

• Starting HIV treatment with lower CD4 cell counts
• Starting HIV treatment at an older age
• Being on an HIV drug regimen containing certain PIs and NRTIs (the longer the time on the regimen the higher the risk)
• HIV itself
• Cigarette smoking
• White race