Endothelial function in HIV-infected patients receiving protease inhibitor therapy: Does immune competence affect cardiovascular risk?

Background: The use of HIV protease inhibitors(PIs) as a component of combination antiretroviraltherapy in HIV-infected patients has been associatedwith dyslipidaemia, but its significance as a riskfactor for cardiovascular disease is unclear.Endothelial dysfunction is an early phase ofatherogenesis that may be assessed non-invasivelywith ultrasonography in vivo.Aim: To evaluate vascular function and investigatepotential determinants of endothelial dysfunctionof the peripheral circulation in PI-treated, HIVinfectedmen with dyslipidaemia.Design: Observational, case-control study.Methods: We studied 24 HIV-infected, PI-treatedmen with dyslipidaemia and 24 normolipidaemic,healthy male controls matched for age and bodymass index. Brachial artery endothelial functionwas studied using high-resolution ultrasound andcomputerized edge-detection software. Thisnon-invasive technique measured post-ischaemicflow-mediated dilatation (FMD), and the endothelium-independent vasodilatory response to glyceryltrinitrate (GTN).Results: Within the HIV patient group, FMD wassignificantly associated with percentage of ‘naı¨ve’CD4þ45RAþ T cells (p¼0.03), while plasmalipid/lipoprotein and insulin levels, body mass,and smoking status did not correlate with endothelialfunction. FMD was not significantly differentbetween the study group and the controls.Conclusions: The atherogenic potential of PIassociateddyslipidaemia may be attenuated inHIV-infected patients with decreased immunecompetence, reflecting a possible contribution ofcell-mediated immune responses to the pathogenesisof atherosclerosis.