Increased oxidative stress in prepubertal severely obese children: Effect of a dietary restriction-weight loss program

Abstract

Oxidant-antioxidant status was investigated in a group of severely obese prepubertal children in comparison with healthy subjects and in relation to a dietary restriction-weight loss program. All subjects underwent anthropometric measurements and determination of lipid profile, lag phase, malondialdehyde (MDA), and vitamin E. Compared with controls, obese children had a significantly higher body mass index (BMI) (28.97 ± 2.42 vs. 16.03 ± 1.88 kg/m2; P = 0.0002) and waist-to-hip ratio (WHR) (0.89 ± 0.03 vs. 0.80 ± 0.01; P = 0.0004); lag phase and vitamin E levels were significantly decreased [24.05 ± 16.21 vs. 43.16 ± 10 min (P = 0.004) and 21.12 ± 14.96 vs. 35.54 ± 13.62 μmol/liter (P = 0.02), respectively], whereas MDA was significantly increased (0.90 ± 0.31 vs. 0.45 ± 0.24 nmol/mg; P = 0.001). Both lag phase and MDA significantly correlated with BMI [respectively, r = -0.34 (P = 0.004) and r = 0.57 (P = 0.002)] and WHR [respectively, r = -0.63 (P = 0.0001) and r = 0.38 (P = 0.04)]. Oxidant status normalized after 6 months of dietary restriction [lag phase, 59.11 ± 14.74 min (P = 0.002); MDA, 0.47 ± 0.09 nmol/mg (P = 0.003)], which was associated with a reduction of BMI (27.34 ± 1.87 kg/m2; P = 0.003), WHR (0.87 ± 0.02; P = 0.001), and fat mass (34.49 ± 2.68%; P = 0.008), but returned to baseline levels together with fatness indexes after another 6 months of free diet. Altered oxidant-antioxidant status is already present in prepubertal severely obese children and is reversible with a dietary restriction-weight loss program, which should be highly encouraged and maintained over time in this age group. Copyright © 2005 by The Endocrine Society.