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

Objective: To assess the effect of replacing protease inhibitors (Pls) with abacavir on insulin sensitivity and plasma lipids. Design: Pilot study including 31 patients with sustained virological contro l on their first PI-containing HAART regimen. 16 patients were switched fro m PIs to abacavir (ABC group), 15 patients continued on PIs (PI group). In all patients, nucleoside-analogue reverse transcriptase inhibitors were con tinued. 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 insul in sensitivity from baseline within 6 months (+49 mu mol/l/min), and a sign ificant 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 hypertri glyceridemia was observed in the majority of patients. In the PI group, no significant changes in insulin sensitivity, triglycerides and cholesterol w ere observed. There was a significant correlation between the changes in in sulin sensitivity, triglycerides and cholesterol. Interpretation: Switching from PIs to abacavir is associated with an improv ement of insulin sensitivity and a decrease of cholesterol and triglyceride s in the majority of patients with HAART-associated metabolic alterations a nd therefore might be an alternative for patients to PI-containing HAART re gimens.