Endothelial function in HIV-infected patients switching from a boosted protease inhibitor-based regimen to raltegravir: a substudy of the SPIRAL study.

OBJECTIVES Raltegravir has been demonstrated to have a favourable impact on several metabolic parameters, including a lack of changes in lipid and glucose concentrations. We aimed to assess the effect on endothelial function of switching from a ritonavir-boosted protease inhibitor (PI/r)-based regimen to raltegravir. METHODS This is a substudy of the SPIRAL study, a multicentre, randomized, open-label clinical trial including HIV-infected patients on a stable PI/r-based antiretroviral regimen and virologically suppressed for at least the previous 6 months. Endothelial function was prospectively evaluated through flow-mediated dilatation (FMD) of the brachial artery at baseline and at weeks 24 and 48. RESULTS Thirty-five HIV-infected patients were included. Sixteen patients were randomly assigned to continue their current PI/r regimen and 19 to switch the PI/r to raltegravir. Total cholesterol, low-density lipoprotein cholesterol and triglycerides decreased at weeks 16 and 32 in the raltegravir-switch arm, while no changes were observed in the PI/r arm. Triglyceride levels were significantly lower in the raltegravir arm than in the PI/r arm at weeks 16, 32 and 48. No significant changes from baseline occurred in FMD at weeks 24 and 48 within or between the raltegravir and PI/r arms. Adjustment for baseline artery diameter did not have a significant effect on the FMD differences. CONCLUSIONS Switching from a PI/r-based antiretroviral regimen to raltegravir in patients with virological suppression has a beneficial impact on the lipid profile, but it does not seem to have a clear impact on endothelial function after a 1 year follow-up.