Cytokine, Chemokine, and Cytokine Receptor Changes Are Associated with Metabolic Improvements after Bariatric Surgery

Context Altered cytokine levels and chronic low-grade inflammation contribute to metabolic dysfunction in obesity. The extent of cytokine changes and their impact on metabolic improvements after bariatric surgery have not been fully explored. Objective To compare 76 circulating cytokines, chemokines, and secreted cytokine receptors in subjects with obesity and lean subjects and determine how these cytokines are altered by bariatric surgery. Design, Setting, and Participants A total of 37 patients with obesity and 37 lean patients in a cross-sectional study at an academic medical center. We also investigated cytokine changes in 25 patients with obesity after bariatric surgery. Intervention Bariatric surgery (Roux-en-Y gastric bypass and vertical sleeve gastrectomy). Main Outcome Measures Quantification of 76 circulating cytokines, chemokines, and secreted cytokine receptors. Results A total of 13 cytokines were significantly higher, and 4 lower, in patients with obesity relative to lean controls. Soluble vascular endothelial growth factor receptor 2 (sVEGFR2), soluble TNF receptor (sTNFR) 1, and sTNFR2 were positively correlated, and soluble receptor for advanced glycation end-products was inversely correlated, with weight and body mass index. sTNFR2 was positively correlated with fasting glucose, homeostatic model assessment of insulin resistance, and hemoglobin A1c. After bariatric surgery, adiponectin increased, and leptin decreased. Elevated sVEGFR2 levels in patients with obesity were decreased (P = 0.01), whereas reduced chemokine (C-X-C motif) ligand (CXCL) 12 levels in patients with obesity increased (P = 0.03) after surgery. Patients with higher soluble interleukin receptor (sIL) 1R2 and sIL-6R levels before surgery had greater weight loss after surgery (P < 0.05). Conclusions We demonstrate that chemokine (C-C motif) ligand (CCL) 14, sVEGFR2, and platelet-derived growth factor BB are elevated in obesity, and CXCL12, CCL11, and CCL27 are lower in obesity. We found clinically concordant directionality between lean and patients with obesity and before vs after surgery for six cytokines, suggesting that bariatric surgery shifted the cytokine profiles of patients with obesity toward that of lean controls.