Endothelial dysfunction is an early marker of atherosclerosis that can be determined non-invasively utilizing assessment of flow-mediated vasodilation (FMD) of the brachial artery, which may be analogous to blood flow through coronary arteries. Using this novel technology and HIV as a model of a chronic inflammatory state, we propose to determine if increasing HDL in subjects with low HDL but no LDL elevation may have potential beneficial effects. Our overall hypothesis for this pilot project is that increasing HDL levels in HIV-infected subjects with low HDL by the use of extended-release niacin over a 12 week period will lead to an identifiable improvement in endothelial function.