OXIDATIVE STRESS DIFFERENCES IN OVERWEIGHT AND OBESE VS NORMALWEIGHTPEOPLE: A PILOT STUDY

Resumen

INTRODUCCIÓN: Oxidative stress, known as the imbalance between anti-oxidant and pro-oxidant factors in favour of pro-oxidants, is important in the pathophysiology of obesity. The increased level of lipid accumulation and the related pathologies (i. E. Hyperglycemia or hyperleptinemia) are involved in this increased oxidative status in the obese. However, it is still unclear if only fat accumulation could alter the oxidative stress status of young people. OBJETIVOS: To know the oxidative stress status of overweight/obese participants and normal-weight counterparts. METODOLOGÍA: Twenty participants (25.4±6.0 Years) with no registered diseases were included in this pilot study (10 normal weight (8 females, Body Mass Index (BMI): 22.3±1.1 Kg/m2), and 10 overweight/obese (6 females, BMI: 31.8. ±3.7 Kg/m2). Fasting blood samples were collected in tubes and stored at -80°C. The activity of antioxidant enzymes (Catalase, Glutathione Peroxidase, and Superoxide Dismutase) as well as the glutathione concentration were determined in diluted erythrocytes lysate. Oxidative markers (malondialdehyde, and advanced oxidation protein products) were determined in blood plasma. Statistical analysis was performed using the t-Student test to compare differences between BMI groups. RESULTADOS: Overweight/obese participants showed higher activity of Catalase (0.69±3.7 Vs 0.32±0.13U/mg prot, p<0.001) And higher concentrations of Malondialdehyde (0.87±0.36 Vs 0.31±0.08 µMol/l, p<0.001). No differences were found for the rest of the oxidative stress markers. CONCLUSIÓN: This pilot study identified that lipid peroxidation is increased in young overweight/obese participants compared to their normal-weight counterparts. Additionally, the antioxidant activity of our overweight/obese participants was similar or even increased in the catalase activity compared to their normalweight counterparts. This augmented enzyme activity, which protects cellular and tissue from peroxidation, could be a consequence of the increased lipid peroxidation which might overstimulate the antioxidant defence until a point that it is depleted.