CLINICAL RESEARCH Reduction in Plasma Levels of Inflammatory and Oxidative Stress Indicators After Roux-En-Y Gastric Bypass Edilson João Cabrera & Antonio Carlos Valezi & Vinicius Daher Alvares Delfino & Edson Lopes Lavado & Decio Sabbatini Barbosa Received: 8 April 2009 / Accepted: 22 September 2009 / Published online: 14 October 2009 # Springer Science + Business Media, LLC 2009 Abstract Background Obesity is considered to be associated with high levels of oxidative stress and inflammation. Antici- pated weight loss secondary to bariatric surgery may offer an opportunity to evaluate this association. We studied a few markers of oxidative stress and inflammation in 20 obese patients submitted to Roux-en-Y gastric bypass (RYGBP). Methods Variations in plasma levels of indicators of oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH), glutathi- one disulfide (GSSG), and total radical antioxidant parameter (TRAP)) and inflammation (α1-acid glyco- protein (AGP) and C-reactive protein (CRP)), as well as variations in plasma levels of leptin, glucose, glycated hemoglobin (HbA1c), and insulin were investigated in the preoperative period and 12 months postsurgery in 20 class III obese individuals submitted to bariatric surgery (obese group) and 20 non-obese individuals (control group). Results Twelve months postsurgery, there was a significant reduction (p <0.01) in median values of BMI (46.75/ 30.17 kg/m 2 ) and in plasma levels of MDA (16.70/ 9.11 nmol/g prot), SOD (10.70/9.24 U/mgHb), GSSG (210.80/148.20 mM/g of Hb), AGP (125.70/75.80 mg/dL), CRP (1.31/0.38 mg/dL), and leptin (15.04/3.58 ng/mL). A significant drop (p <0.05) in plasma levels of HbA1c (5.81/4.98%) was also observed. On the other hand, a significant increase in plasma levels of GSH (2.002/ 2.823 mM/g of Hb) and TRAP (585.40/815.48 μM Trolox®), p <0.01, and in catalase plasma levels (12.06/ 13.22 Δt/mgHb/min), p <0.05, was seen. No statistically significant variations in glucose (96.3/84.8 mg/dL) or insulin plasma levels (9.91/7.88 U/mL) occurred. Calculated homeostasis model assessment index did not statistically change 12 months postsurgery (2.36/1.66). Conclusions In the preoperative period, the obese group individuals showed higher oxidation and inflammation levels and lower indices of antioxidant defense than those of the control group. One year after RYGBP, an improvement in antioxidant protection, associated with a reduction in inflammatory and oxidative markers, was observed, indicating that these individuals presented a lower degree of oxidative stress. Keywords Obesity . Inflammatory markers . Oxidative stress indicators . Roux-en-Y gastric bypass E. João Cabrera Pharmaceutical University Hospital, University Hospital, Londrina State University, Londrina, Brazil A. C. Valezi Department of Surgery, University Hospital, Londrina State University, Londrina, Brazil V. D. A. Delfino Department of Internal Medicine, University Hospital, Londrina State University, Londrina, Brazil E. L. Lavado Department of Physiotherapy, University Hospital, Londrina State University, Londrina, Brazil D. S. Barbosa (*) Department of Pathology, Clinical Analysis and Toxicology, University Hospital, Londrina State University, Av. Robert Koch, 60, 86038-350 Londrina, Paraná, Brazil e-mail: sabatini@sercomtel.com.br OBES SURG (2010) 20:42–49 DOI 10.1007/s11695-009-9988-2