Improvement of HAART-associated insulin resistance and dyslipidemia after replacement of protease inhibitors with abacavir.

OBJECTIVE: To assess the effect of replacing protease inhibitors (PIs) with abacavir on insulin sensitivity and plasma lipids. - DESIGN: Pilot study including 31 patients with sustained virological control on their first PI-containing HAART regimen. 16 patients were switched from PIs to abacavir (ABC group), 15 patients continued on PIs (PI group). In all patients, nucleoside-analogue reverse transcriptase inhibitors were continued. METHODS: Insulin sensitivity (using an intravenous insulin tolerance test) and fasting total cholesterol and triglycerides were determined at baseline, month 3, 6, 9 and 12. RESULTS: In the ABC group, there was a significant increase in median insulin sensitivity from baseline within 6 months (+ 49 micromol/l/min), and a significant decrease in both triglycerides (-41mg/dl) and cholesterol (-40mg/dl) at month 3. These changes were sustained through month 12. In addition, a reversal of baseline insulin resistance, hypercholesterolemia and hypertriglyceridemia was observed in the majority of patients. In the PI group, no significant changes in insulin sensitivity, triglycerides and cholesterol were observed. There was a significant correlation between the changes in insulin sensitivity, triglycerides and cholesterol. INTERPRETATION: Switching from PIs to abacavir is associated with an improvement of insulin sensitivity and a decrease of cholesterol and triglycerides in the majority of patients with HAART-associated metabolic alterations and therefore might be an alternative for patients to PI-containing HAART regimens.