Background: Bariatric surgery improves oxidative damage, but little is known about the differences between Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). This study compared changes in lipid and protein oxidative damage markers and their correlations with body parameters of patients before and after RYGB or SG.
Methods: Body mass index (BMI), bioimpedance parameters, and biochemical parameters including lipid and protein oxidative damage markers were evaluated before and 6 months after surgery. Data were analyzed by t test or Mann-Whitney rank sum test and Spearman's correlation coefficient between oxidative damage and other parameters.
Results: Twenty-five patients were submitted to RYGB and 14 to SG. There was a significant decrease of BMI, fat mass, fat-free mass, phase angle, serum total protein, transthyretin, and C-reactive protein in both groups (p < 0.05). Serum thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), and serum lipids (p < 0.05) were significantly decreased in the RYGB group. TBARS levels were significantly correlated with serum total cholesterol (r = 0.468), LDL (r = 0.439), BMI (r = 0.424), and fat mass (r = 0.40) (p < 0.05). In the SG group, AOPP levels were significantly correlated with serum C-reactive protein (baseline: r = 0.53, 6 months: r = 0.64) (p < 0.05). Alterations in these levels were negatively correlated with changes in BIA parameters [resistance (r = -0.574), reactance (r = -0.736), and phase angle (r = 0.549)] (p < 0.05).
Conclusions: RYGB seems to be better in attenuating oxidative damage after 6 months. The BMI reduction in the RYGB group suggests a concomitant decrease of lipid oxidative damage. In the SG group, changes in BIA parameters were inversely correlated with protein oxidative damage.
Keywords: Bioimpedance; Lipid oxidation; Obesity; Oxidative stress; Protein oxidation.