Oxidative stress in childhood obesity

To measure products of free radical damage in childhood obesity.

Plasma free radicals were assayed in 24 children with exogenous obesity and 24 non-obese healthy controls. A new colorimetric method was used that measures the generation of peroxy radicals (D-Roms), first products of the reaction between free radicals and oxygen.

D-Roms levels were higher in the obese children than in the non-obese group (33.3+/-10.1 mg% of H2O2 vs 22.8+/-2.8 mg% of H2O2; p <0.001). Moreover, D-Roms levels were higher in children with hyperlipidemia than in children with normolipidemia (49.6+/-3.1 mg% of H2O2 vs 27.8+/-3.2 mg% of H2O2; p <0.001). D-Roms level was positively correlated with waist-hip ratio, serum total cholesterol, serum triglycerides, serum low-density lipoprotein-cholesterol, systolic blood pressure, diastolic blood pressure and fasting blood glucose in obese children. In a multivariate regression model for obese children, the independent correlates for D-Roms level were systolic blood pressure (p <0.001) and serum total cholesterol (p <0.001), with the total variance explained being 82%.

Our study demonstrates for the first time that there was increased D-Roms levels in obese children and adolescents and suggests that increased systolic blood pressure associated with hyperlipidemia may independently contribute to increased oxidative stress in childhood obesity.