Cardiovascular disease (CVD) is responsible for 25% of deaths in the United States, and chronic inflammation contributes to risk. A growing body of evidence suggests that gut-derived bacterial components (e.g., lipopolysaccharide or LPS) entering the bloodstream when the gut barrier fails (i.e., intestinal permeability) are a prominent source of inflammation in cardiometabolic conditions such as metabolic syndrome, coronary artery disease, and type 2 diabetes. Two groups that are at > 2x the risk for CVD, but largely still free of overt disease, are those with metabolically healthy obesity and normal-weight obesity. Those with metabolically healthy obesity - defined as having an obese body mass index (BMI) but other clinical risk factors in the normal range (e.g., blood lipids) - and normal-weight obesity - defined as having a normal BMI yet high percent body fat - generally display little evidence of clinical risk, but present with elevated inflammatory markers including C-reactive protein (CRP), tumor necrosis factor (TNF)-a, and interleukin (IL)-6). Therefore, it is likely that chronic inflammation is largely driving CVD risk in metabolically healthy and normal-weight obesity, but the source of this inflammation remains unclear. The primary aim of the proposed project is to determine the extent that markers of intestinal permeability are elevated in metabolically healthy obesity and normal-weight obesity compared to healthy controls and individuals with metabolic syndrome.
The investigators are examining the extent gut permeability explains observed inflammation in normal-weight and metabolically healthy obesity (and potentially cardiovascular disease risk).