It is well known that HIV-infected subjects frequently experience hyperlipidemias, insulin resistance, and visceral adiposity, which are known to increase the risk of atherosclerosis. Several cohorts have shown an increased risk of heart disease in people with HIV. The effect of HIV treatment versus HIV itself on the incidence of heart disease is unclear. In this study the investigators will assess the effect on carotid IMT of the initiation of antiretroviral combinations that are known to have a minimal effect on lipids and insulin resistance. We will also assess the changes in several inflammation and cardiovascular markers,as well as endothelial activation markers,and how these changes relate to therapy-induced changes in immunologic, virologic and metabolic markers.

Inclusion Criteria for HIV positive group:

• HIV-1 infection
• Age at least 18 years
• Naïve to antiretroviral therapy
• CD4 cell count > 400 cells/mm3

For controls: Age at least 18 years, no known HIV infection, and no known medical condition requiring chronic use of prescription medications.

Exclusion Criteria (both groups):

• Diabetes
• Pregnant or breastfeeding
• Women of child bearing age who refuse or are unable to use appropriate methods of contraception during the entire study period.
• Active infectious or inflammatory condition
• In jail or involuntarily incarcerated

80 HIV-infected adults older than 18 years of age, ART-naïve with CD4 count of at least 400 cells/mm3

The control group will be adults, healthy controls with no active infection or inflammatory condition, who are matched by gender and age to the HIV positive group