Elevated advanced oxidation protein products (AOPPs) indicate metabolic risk in severely obese children

Background and aims: The assessment of oxidative stress may aid in the identification of subsequent metabolic risk in obese children. The objective of this study was to determine whether the plasma level of advanced oxidation protein products, analyzed with a recently proposed modified assay that involves a delipidation step (mAOPPs), was related to metabolic risk factors (MRFs) in severely obese children. Methods and results: The plasma levels of mAOPPs were determined by spectrophotometry in 54 severely obese and 44 healthy children. We also measured lipid peroxidation biomarkers (thiobarbituric acid-reactive substances, malondialdehyde, and 8-isoprotane F-2 alpha) and sulfhydryl groups, a marker of antioxidant defense. Protein oxidation and lipid peroxidation markers were higher and sulfhydryl levels were lower in obese children compared with controls. Taking metabolic risk into account, obese children were subdivided according to the cutoff point (53.2 mu mol/L) obtained for their mAOPPs values from the ROC curve. Anthropometric measures and the existence of hypertension did not differ between groups. The presence of dyslipidemia and insulin resistance was significantly higher in the group with higher mAOPPs levels. The highest levels of mAOPPs were found in the children with >= 3 MRFs. The level of mAOPPs was positively correlated with triglycerides and negatively correlated with high-density lipoprotein cholesterol. There was no correlation of this marker of protein oxidation with biomarkers of lipid peroxidation. Conclusion: The determination of mAOPPs in delipidated plasma is an easy way to evaluate protein oxidation. It may be useful in severely obese children for better cardiovascular risk assessment. (C) 2010 Elsevier B.V. All rights reserved.