Changes in the amount of fat and how that fat was distributed were reported after the introduction of antiretroviral therapy (ART) for HIV infected patients. Increases in diabetes, heart disease, and blood levels of glucose and fats have also been reported. However, the cause for these changes is still unclear, in part because clinical measures have not been consistent between different trials. The contribution of age, duration of HIV infection, duration and types of ART, and body weight on metabolic changes need to be defined, and the relationship between metabolic disturbances and body composition changes has also not been established. The purpose of this study is to examine HIV infected adults and use objective measurements of fat to determine metabolic changes in this population, their causes, and possible associations with other observed changes. Data from this study will help guide future treatment plans for HIV infected people to help prevent or lessen the risk for diabetes and cardiovascular disease.

There are 2 parts to this study. Part 1 will examine fat redistribution; there will be 2 groups in Part 1. Group 1 participants will be HIV infected adults recruited from specific HIV clinics. Group 2 participants will be HIV uninfected adults currently enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants will undergo hands-over-head-to-toe wide-slice magnetic resonance imaging (MRI) and dual energy x-ray absorptiometry (DEXA). Imaging measurements will be compared to anthropometric measurements to determine whether anthropometric measurements can accurately quantify fat redistribution. Participants will be asked to self-report fat distribution abnormalities, and this self-reporting will be evaluated for accuracy as compared to the quantitative measures of regional fat distribution. Blood collection will also occur to determine the possible association of body composition changes with the types of ART a participant may have taken or currently be taking.

Part 2 of this study will examine cardiovascular disease and factors for its development; there will be 2 groups in Part 2. Group 1 participants will be HIV infected adults recruited from specific HIV clinics. Group 2 participants will be HIV uninfected adults currently enrolled in the CARDIA study. All participants will be assessed for blood pressure, family history, lifestyle habits, and regional fat volumes by MRI and DEXA. Blood collection will occur to test for glucose and lipids (traditional metabolic risk factors) and C-reactive protein (CRP) and cytokines (novel inflammatory risk factors). Participants will also undergo a carotid intimal medial thickness (IMT) measurement by ultrasound to determine the prevalence of atherosclerosis in this population and associated contributing factors.

For Part 2, there will be a minimum of 2 visits. At both visits, fasting blood collection will occur. A physical exam and self-reporting of lifestyle habits, and completion of questionnaires about smoking, alcohol use, and medical and family history will occur at the first visit.