Changes in C-reactive protein predict insulin sensitivity in severely obese individuals after weight loss surgery

The production of inflammatory mediators by abdominal adipose tissue may link obesity and insulin resistance. We determined the influence of systemic levels of interleukin-6 and C-reactive protein on insulin sensitivity after weight loss via Roux-en-Y gastric bypass surgery. Severely obese individuals (n 5 15) were evaluated at baseline and at 6 months after surgery. Insulin sensitivity was determined by frequently sampled intravenous glucose tolerance testing at the same time points. Visceral and subcutaneous adipose tissue volumes were quantified by computed tomography. Interleukin-6 and C-reactive protein were measured by enzyme-linked immunoassay in plasma and in adipose tissue biopsies. Correlation analysis was used to determine associations between insulin sensitivity and other outcome variables. Significance was set at P < 0.05. Plasma interleukin-6 concentrations were significantly correlated to the IL-6 content of subcutaneous adipose tissue (r = 0.71). At 6 months postsurgery, subcutaneous and visceral adipose tissue volumes were significantly reduced (34.7% and 44.1%, respectively) and insulin sensitivity had improved by 160.9%. Significant longitudinal correlations were found between insulin sensitivity and plasma C-reactive protein (r = 20.61), but not plasma interleukin-6 at 6 months. These findings offer insights that link obesity and insulin resistance via the activity of inflammatory mediators. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Supported by National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases 1R03 DK067167-01A1 (N.G.), the Emory University Research Committee Grant (N.G.), and the National Institutes of Health/National Center for Research Resources General Clinical Research Center Grant M01 RR00039 (N.G., E.L.).