Obesity, bariatric surgery and oxidative stress.

Introduction: Obesity refers to the accumulation of fatty tissues and it favors the occurrence of oxidative stress. Alternatives that can contribute to body weight reduction have been investigated in order to reduce the production of reactive oxygen species responsible for tissue damage. The aim of the current study was to assess whether the oxidant and antioxidant markers of obese women before and after bariatric surgery were able to reduce oxidative damage. Method: We have assessed 16 morbidly obese women five days before and 180 days after the surgery. The control group comprised 16 non-obese women. Levels of thiobarbituric acid-reactive substances, carbonylated proteins, reduced glutathione and ascorbic acid were assessed in the patients' plasma. Results: Levels of lipid peroxidation and protein carbonylation in the pre-surgical obese women were higher than those of the controls and post-surgical obese women. Levels of reduced glutathione in the pre-surgical obese women were high compared to the controls, and declined after surgery. Levels of ascorbic acid fell in the pre--surgical obese women compared to the control and post-surgical obese women. Conclusion: Body weight influences the production of reactive oxygen species. Bariatric surgery, combined with weight loss and vitamin supplementation, reduces cellular oxidation, thus reducing tissue damage.