Association of Uric Acid with Obesity and Endothelial Dysfunction in Children and Early Adolescents

Abstract

Background: Hyperuricemia in adults is known to be associated with hypertension, the metabolic syndrome and cardiovascular disease. The purpose of this study was to elucidate the factors associated with hyperuricemia in obese children and early adolescents and to investigate the threshold serum level of uric acid (UA) for the metabolic syndrome in children. Methods: We assessed anthropometric measurements, blood pressure, body composition and biochemical data in 1,559 obese children. To assess endothelial dysfunction, flow-mediated dilatation (FMD) was measured in 92 children. The correlations between serum UA levels and various parameters were examined. The threshold serum UA level for the metabolic syndrome was calculated by receiver-operating characteristic (ROC) curve analysis. Results: Serum UA levels were positively correlated with lipids in both boys and girls, and they were inversely correlated with FMD in the boys but not the girls. The threshold serum UA level for the metabolic syndrome was 5.25 mg/dl in boys and 5.05 mg/dl in girls. However, the specificity and sensitivity of ROC curve analysis are not so striking. Conclusion: The correlation between UA and FMD showed gender differences and might be affected by the hormonal status. The cutoff level of serum UA as a marker of the metabolic syndrome in obese children was affected by both age and gender.