A matter of fat: insulin resistance and oxidative stress

作者：Codoner Franch Pilar^*; Navarro Ruiz Almudena; Fernandez Ferri Maria; Arilla Codoner Angela; Ballester Asensio Esther; Valls Belles Victoria

来源：Pediatric Diabetes, 2012, 13(5): 369-376.

DOI：10.1111/j.1399-5448.2011.00847.x

• HOMA-IR
• obesity
• oxidative stress
• type 2 diabetes mellitus

Background Obesity is linked to insulin resistance (IR), which can lead to type 2 diabetes mellitus. Oxidative stress present in early obesity may favor the progression to comorbid conditions. Objective To examine the relationship between oxidative stress biomarkers and the severity of IR in a group of obese children. Methods Forty obese children with a body mass index (BMI) Z-score = 2 were divided into two groups using the median obtained for the homeostasis model assessment of IR (HOMA-IR). Anthropometric parameters (including body fat composition by bioelectrical impedance) and biochemical parameters were assessed. The following biomarkers of oxidative stress were measured: malondialdehyde (MDA), carbonyl groups (CG), reduced glutathione, oxidized low-density lipoprotein, and vitamin E. Comparisons were adjusted for gender and Tanner stage. Results Children with high values of HOMA-IR were more likely to have high body fat percentage and waist circumferences. However, the BMI Z-score did not correlate to the level of IR. Children with higher values of HOMA-IR presented increased levels of markers of oxidative stress in lipids (MDA, p = 0.005) and proteins (CG, p = 0.015). Moreover, MDA increased with increasing levels of HOMA-IR (r = 0.50, p = 0.002), suggesting that lipoperoxidation increases as IR worsens. In a multivariate regression model, only HOMA-IR was predictive of MDA values, irrespective of adiposity parameters and other metabolic risk factors (r2 = 0.22, p = 0.002). Conclusions Oxidative stress increases in obese children according to the severity of IR, which could be linked to the development of comorbidities.

• 出版日期2012-8