Carotid artery intima-media thickness and HIV infection: Traditional risk factors overshadow impact of protease inhibitor exposure

Context: The impact of HIV infection and exposure to antiretroviral therapy on the development of subclinical atherosclerosis is incompletely understood. Objective: To compare intima-media thickness (IMT) of the carotid artery between HIV-infected subjects receiving protease inhibitor-containing regimens and subjects not receiving these regimens and to compare differences in the IMT of the carotid artery between HIV-infected subjects and HIV-uninfected subjects. Methods: A prospective matched cohort study in university-based outpatient clinics. Groups of three individuals (triads) matched on the following characteristics were enrolled: age, sex, race/ethnicity, smoking status, blood pressure and menopausal status. Group 1, HIV-infected subjects with continuous use of protease inhibitor (PI) therapy for ≥ 2 years; group 2, HIV-infected subjects without prior PI use; and group 3: HIV-uninfected. Ultrasonographers at six sites sent standardized ultrasound images to a central reading site for carotid IMT measurements. Carotid IMT was compared within the HIV-infected groups (1 and 2) and between the HIV-infected and uninfected groups in a matched analysis. Results: One hundred and thirty-four individuals were enrolled in 45 triads. The median IMT in groups 1, 2 and 3 was 0.690, 0.712 and 0.698 mm, respectively. There were no statistically significant differences in IMT between groups 1 and 2, or in the combined HIV groups compared with the HIV uninfected group. Significant predictors of carotid IMT in a multivariate model included high-density lipoprotein (HDL) cholesterol, the interaction of HDL cholesterol and triglycerides, age and body mass index. Conclusions: We found no association between PI inhibitor exposure or HIV infection and carotid IMT.