Switch to abacavir improves lipoatrophy
Simon Collins, HIV i-Base
Any study that shows an improvement in lipoatrophy, the most difficult of lipodystrophy symptoms to reverse, is worth studying closely. This study is particularly important as it is an independent study run by Andrew Carr and David Cooper, two of the leading and earliest researchers in lipodystrophy.
This study randomised 111 patients (98% male) with moderate to severe lipoatrophy to either continue with their current regimen or switch zidovudine (ZDV) (16%) or stavudine (d4T) (84%) to abacavir.
After six months there was a significant increase in limb fat in the group that switched to abacavir compared to those who didn’t switch their nucleoside (0.39kg and 0.08 kg, respectively; p=0.016). There were also significant relative increases in subcutaneous thigh and abdominal fat areas (p<0.02). Although these changes were small – and patients did not report subjective improvements – the results are important. In this study, use of MRI and DEXA scans provided the sensitivity of monitoring that is required for research – and arguably for treatment – in this area.
It was interesting that patients continuing without a nucleoside switch did not continue to lose fat, although it is difficult to know whether this stabilisation occurred because lipoatrophy was advanced, and that an earlier switch in people with mild lipoatrophy would also prevent further loss. It may be that switching to drugs with a more beneficial lipid profile is one part of a multi-structured approach.
Hypersensitivity reactions to abacavir occurred in five (10%) patients and there was no significant effect on intra-abdominal fat, lipid or glycaemic parameters. Previous studies have highlighted that switching to abacavir is associated with higher risk of viral rebound in patients with previous nucleoside exposure in failing or suboptimal combinations. Switching d4T or ZDV to abacavir and tenofovir may be a more appropriate choice for these patients. Although the effect of such a switch on lipoatrophy remains unknown.
Carr A – Switching Stavudine or Zidovudine to Abacavir for HIV Lipoatrophy: A Randomised, Controlled, Open-Label, Multicentre, 24-Week Study. Abstract 32.