Background: Surgical treatments of obesity have demonstrated rapid improvements in insulin sensitivity and oxidative stress. The current study focuses on metabolic and oxidative stress differences between obese patients with or without type 2 diabetes mellitus (T2DM) prior and after metabolic surgery (Laparoscopic Sleeve Gastrectomy). Objective: The aim of this preliminary study was to evaluate the oxidative stress status and adipokines in obese patients prior to metabolic surgery, in order to assess the differences between diabetic and non-diabetic patients. Material and methods: 12 obese patients with T2DM and 17 nondiabetic obese subjects undergoing bariatric surgery were compared regarding anthropometric, clinical and oxidative stress markers. In all individuals we assessed BMI, waist and hip circumference, visceral fat index, serum levels of leptin, adiponectin, insulin and proinsulin. In order to evaluate the oxidative stress status of isolated peripheral blood mononuclear cells (PBMC) we measured the NADPH oxidase activity by luminol enhanced chemiluminescence (“respiratory burst” – RB) while their antioxidant activity was evaluated by measuring paraoxonase 2 (PON2) lactonase activity towards dihydrocoumarin (DHC). Total antioxidant capacity (TEAC), “Antioxidant gap” (GAP) and fructosamine levels were determined as well.
Results: All oxidative stress markers investigated were statistically significant modified for T2DM, except RB that do not differ in diabetic patients from those who are non-diabetic; they had decreased levels of TEAC (p<0.05), adiponectin (p<0.05) and PON2 (p<0.05) and increased proinsulin (p<0.05) and fructosamine (p<0.05) levels. The obesity anthropometric markers were positively correlated with the values for leptin (p<0.05) and negatively with the values for adiponectin (p<0.05) and this was consistent with the increased insulin and proinsulin levels (p<0.001) in obese patients with T2D vs. non-diabetic subjects. PON2 lactonase activity was most correlated with diabetic parameters (glycaemia, fructosamine, proinsulin) and not with obesity ones (waist circumference, BMI, triglycerides).
Conclusion: The present study demonstrates a major disturbance of oxidant antioxidant balance in obese patients with T2DM. The increased oxidative stress in T2DM patients is nowadays considered to be the determinant factor that increases the chance for the onset of the metabolic syndrome. The influence of metabolic surgery over the oxidative stress in both cohorts is to be determined.Full text sources