Background:  Increased risk of coronary artery disease (CAD) is a concern for HIV-infected persons because of standard risk factors in addition to HAART- and HIV-related contributions to atherosclerosis.

Methods:  The Study to Understand the Natural History of HIV/AIDS (SUN) is a prospective cohort of 687 HIV-infected patients receiving care at clinics in Denver, Minneapolis, Providence, and St. Louis. At baseline, carotid intima-media thickness (cIMT), carotid artery calcium scores (CACS) by CT scan, and clinical and fasting laboratory data were obtained on all subjects. We used multivariate logistic regression to identify independent predictors of increased cIMT from among factors significant in univariate analyses. Odds ratios were determined using cIMT >median value. cIMT, CACS, and Framingham risk scores (FRS) were correlated. cIMT of subjects was compared with that of a healthy HIV-uninfected cohort from the University of Southern California who had similar distribution of cardiovascular disease (CVD) risk factors, matched by age, gender, and diabetes.

Results:  Characteristics of 258 subjects with available data who could be matched to HIV-negative persons were as follows:  median age 44 years, 23% women, 22% African American, median body mass index 25.1 kg/m², median CD4 cell count 447 cell/µL, 46% active smokers, 11% active cocaine users, 22% hypertensive, 9% diabetic, and 84% on HAART. In multivariate analyses, higher cIMT in SUN subjects was associated with male gender (odds ratio [OR] 3.4, 95%confidence interval [CI] 1.7 to 7.4), African American race (OR 3.0, CI 1.5 to 6.4), age >44 years (OR 2.2, CI 1.3 to 3.7), hypertension (OR 2.2, CI 1.3 to 3.9), and having ever smoked tobacco (OR 2.2, CI 1.2 to 3.9), but not type/duration of HAART. Compared to HIV-uninfected persons, SUN subjects had higher median cIMT (0.74 vs 0.69 mm, p <0.001). This difference persisted in the subset of 139 pairs with matched current smoking status (0.73 vs 0.70 mm, p = 0.005). Groups did not differ by race or prevalence of hypertension, elevated fasting glucose, or menopause. Despite higher triglycerides, SUN subjects had lower HDL and LDL cholesterol, lower body mass index, and lower FRS (all p <0.001) than those of HIV-negatives. In 246 SUN subjects with baseline cIMT, CACS, and FRS, the FRS correlated moderately well with both cIMT (r = 0.38) and CACS (r = 0.32; both <0.001 by Spearman’s rank test).

Conclusions:  HIV-infected persons had higher cIMT compared with matched HIV-uninfected controls, but overall CVD risk was low in this cohort. Traditional CAD risk factors outweighed the contribution of HAART to increased cIMT and as captured by FRS, correlated moderately with cIMT and CACS.