Oxidative Stress Biomarkers In Sedentary Obese Children

Abstract

Oxidative stress injures cellular membrane structure and eventually causes damage to other cellular components as DNA and proteins; this is due to the high production of reactive oxygen species. The impairment represents a critical situation to cellular function which in turn affects the signaling process and triggers several pathologies as obesity, type 2 diabetes mellitus and different types of cancer. Administration of specific physical activity and dietary habits as antioxidant system must be based on the knowledge of the oxidative stress biomarkers role for recognition of DNA injure. PURPOSE: To determine DNA damage and total antioxidant capacity (TAC) related to fasting blood glucose in sedentary obese children. METHOD: Eleven sedentary obese children 9.5 ± 1.2 years old, 55.4 ± 9.1 kg of weight, 141.1 ± 6.6 cm of height, 91 ± 7.1 cm of waist circumference (WC) and 27.7 ± 3.3 kg/m2 of BMI were evaluated. Apurinic/apyrimidinic sites (APS) were recognized in DNA structure as oxidative damage evidence. TAC was measured by Trolox equivalents and fasting blood glucose was determined by colorimetric-enzymatic technique. Descriptive statistics and Pearson coefficient correlation at p<0.05 significance level were used. RESULTS: Children evidenced severe obesity (BMI ≥ 97 percentile) according to the Public Health Institute of Mexico classification (INSP, 2006; CDC charts, 2000); WC was higher than reported by McCarthy et al (2001); 4.0 ± 4.1 APS × 105 and TAC of 0.218 ± 0.03 mmol/L were found. An inverse relationship between APS and TAC were encountered (r= -0.629, p=0.038) revealing an imbalance of redox state in cell function. TAC and WC were positively related (r= 0.612, p= 0.045) which could be associated to a compensatory response to the increased intra-abdominal fat accumulation. Meantime, fasting blood glucose (96 ± 4.5 mg/dl) showed a near significant inverse relationship with TAC (r= -0.568, p= 0.068). CONCLUSIONS: Normal-high blood glucose seems to be related to oxidative stress in this group of obese children. Greater efforts should be made to accurately determine the extent of this association as risk to develop type 2 diabetes mellitus. Significance of APS to reflect impairment in DNA must be also accurately determined as well as the role of the physical activity as major antioxidant in these early stages of life.