OBJECTIVETo investigate whether overweight and obesity might cause oxidative stress and potential oxidative damage in overweight and obese children, and to explore its possible mechanism.

METHODSEighty-five overweight and obese children (OOC), and eighty-five age-matched healthy children (HC) were recruited in this case-control study. The present study analyzed spectrophotometrically vitamin C (VC), vitamin E (VE), and 3-carotene (P-CAR) in plasma, as well as the activities of superoxide dismutase (SOD), catalase (CAT), and the level of malondialdehyde (MDA) in erythrocytes.

RESULTSCompared with those of VC, VE, P-CAR, SOD, CAT and MDA in the HC group, the average values of VC, VE, 3-CAR, SOD, and CAT in the OOC group were significantly decreased (P<0.001), while the average value of MDA in the OOC group was significantly increased (P<0.001). The regression analysis demonstrated that VC, VE, P-CAR, SOD, and CAT were negatively correlated (P<0.05-0.01), and MDA was positively correlated with BMI (P<0.05). Fitting to the model of multiple stepwise regression of BMI on VC, VE, P-CAR, SOD, CAT, and MDA in 85 OOC was Y= 27.0041 + 0.2541MDA - 2.1448beta-CAR - 0.0090CAT, where F= 43.8088, P<0.001, r = 0.7866, r(2)= 0.6187, adjusted r(2)= 0.6046. The findings from the reliability analysis for VC, VE, P-CAR, SOD, CAT, and MDA used to reflect increased oxidative stress and potential oxidative damage in the OOC showed that the reliability coefficients (alpha, 6 items) = 0.7231, P<0.0001, and that the standardized item alpha = 0.9207, P<0.0001.

CONCLUSIONThe present study suggests that there exists an increased oxidative stress in overweight and obese children.