Dr. Powderly expressed concern that most of the studies to date have been based on observational data, rather than on metabolic studies. These would include insulin sensitivity, lipid levels in a fasting state, and body composition studies. Several studies at this conference pointed to underlying NRTI resistance as the reason for failure. Caution must be exercised in making this switch in experienced patients without genotyping. Other studies have shown mixed results.
Protease inhibitors affect triglycerides in some patients.
Stavudine may have a role in lipodystrophy. Decreased insulin resistance. Usually decreased triglycerides, although not necessarily back to a normal level. No consistent effect of fat gain or loss. No consistent effect on body habitus.