 Insulin resistance has been implicated as the central mechanism in the development of several cardiovascular risk factors including hypertension, diabetes, lipid disorders, and coagulation disorders. Recent evidence suggests that increased levels of a circulation fat free fatty acids or FFAs are a leading candidate causing insulin resistance. Our preliminary studies in indicate that, in addition to insulin resistance, the infusion of Intralipid and heparin to increase FFAs resulted in a significant rise in systolic and diastolic blood pressure, impaired endothelial vascular function, and increased inflammatory markers in obese African Americans with and without diabetes. The effects of FFA on insulin action are well established; however, the blood pressure and vascular effects of FFAs infusion in obese subjects have not been fully investigated. We hypothesize that observed changes in blood pressure are the result of acute endothelial dysfunction, andor increased activation of the autonomic nervous system. No previous studies have attempted to determine a dose response effect of increasing FFA on blood pressure. In addition, it is not know if increased FFAs by repeated oral fat load results in similar blood pressure than intravenous lipid infusion. Accordingly, we propose: 1 a systematic evaluation of the effects of increasing FFA levels on blood pressure and endothelial vascular function, and 2 determine the effects of comparable increases in FFA concentration via intravenous infusion of Intralipid or by repeated oral fat load on blood pressure, insulin resistance and endothelial dysfunction in obese subjects. 