This study is a single site, open-label, "baseline-controlled" (pre LPS saline period) study examining the pro-atherosclerotic metabolic responses and safety responses to a single administration low-dose (3 ng/kg) endotoxin (LPS) in 20 additional non-metabolic syndrome participants: 10 healthy overweight and 10 healthy lean counterparts (20 non-metabolic syndrome participants were studies in first phase), and 40 subjects with the metabolic syndrome. We are continuing to use an approach whereby "metabolic syndrome" subjects will be recruited to have key metabolic syndrome abnormalities that are sensitive to insulin resistance compared to the non-metabolic syndrome groups, although all of these "metabolic syndrome" subjects may not fulfill traditional NCEP criteria for the syndrome.