Changes in leptin, plasminogen activator factor and oxidative stress in morbidly obese patients following open and laparoscopic Swedish adjustable gastric banding

Background: Oxidative stress is increased in obesity, leading to endothelial dysfunction, atherogenesis, and platelet aggregation. The purpose of this study was to determine the effects of weight loss after bariatric surgery on serum lipids, malondialdehyde (MDA, a marker of oxidative stress), oxidized low-density lipoprotein (oxLDL, which is increased in obesity and causes endothelial dysfunction), paraoxonase (PON-1, which inhibits lipid peroxidation), leptin and plasminogen activator inhibitor type-1 (PAI-1, which contributes to a thrombotic state). Methods: 40 morbidly obese patients had insertion of a Swedish adjustable gastric band (SAGB). A lipid profile, MDA, oxLDL, PON-1, leptin and PAI-1 levels were drawn before and 6 months after the operation. 20 patients underwent open (Group 1) and 20 laparoscopic (Group 2) SAGB, to compare the systemic inflammatory response of the two approaches. Results: Patient demographics, indications for surgery, and postoperative results were no different between the groups. Postoperative BMI and concentrations of lipid, MDA, oxLDL, leptin and PAI-1 decreased significantly in both groups. PON-1 activity increased and was negatively correlated with BMI (r=-0.618, P< 0.01), MDA (r=-0.735, P<0.001), oxLDL (r=-0.701, P< 0.01), leptin (r=-0.626, P< 0.01) and PAI-1 (r=-0.461, P<0.05). There was a correlation between BMI and MDA (r=0.790, P<0.001), and also leptin (r=0.900, P<0.001) and PAI-1 (r=0.888, P=0.001). There was no correlation between BMI and oxLDL. Conclusion: These findings support the hypothesis that in morbid obesity, weight loss after surgery has positive effects on fibrinolytic function, oxidative stress and antioxidant activity. Both operative approaches had similar effects in this study.