Background Human immunodeficiency virus protease inhibitors (HIV PIs) are associated with hyperlipidemia, hyperglycemia, and obesity; however, it is not known whether they increase risk of atherosclerotic vascular disease. The purposes of this study were to characterize the lipoprotein abnormalities associated with use of HIV PIs in individuals with HIV infection and to determine the pathophysiological significance of these changes by assessing their effect on endothelial dysfunction.

Methods and Results This was a cross-sectional study of 37 adults with HIV-1 infection who were receiving antiretroviral therapy. Twenty-two were taking HIV PIs (group 1); 15 were not (group 2). Lipids and lipoproteins were measured by enzymatic techniques and nuclear magnetic resonance spectroscopic analysis. Flow-mediated vasodilation (FMD) of the brachial artery was measured by high-resolution ultrasound. Subjects in both groups were similar in regard to age, time since diagnosis of HIV infection, and CD4 cell count. Group 1 subjects had higher total cholesterol (5.68 versus 4.42 mmol/L, P=0.007) and triglyceride (4.43 versus 1.98 mmol/L, P=0.009) levels, characterized by elevated levels of IDL and VLDL. Subjects in group 1 had impaired FMD (2.6±4.6%), indicative of significant endothelial dysfunction. Group 2 subjects had normal FMD (8.1±6.7%, P=0.005). In group 1, chylomicron, VLDL, IDL, and HDL cholesterol levels predicted FMD.

Conclusions Use of HIV PIs is associated with atherogenic lipoprotein changes and endothelial dysfunction. Because these metabolic and vascular changes predispose to atherosclerosis, monitoring and treatment of dyslipidemia in patients taking these medications is warranted.