title: Early increase of NOX2-derived oxidative stress in children: relationship with age.
abstract: BACKGROUND
  Studies conducted in the prepubertal period showed that biomarkers of oxidative stress decreased with increasing age in normocholesterolemic children (NC), and, conversely, they are persistently high in hypercholesterolemic children (HC). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the most important cellular source of reactive oxygen species. No data have been reported concerning the behavior of age-related oxidative stress generated by NOX2, the catalytic subunit of NADPH oxidase, in children.
  
  
  METHODS
  We performed a cross-sectional study comparing oxidized low-density lipoprotein (ox-LDL), as a marker of oxidative stress, and NOX2 activity, as assessed by blood levels of soluble NOX2-derived peptide (sNOX2-dp), in a population of 250 children, including 125 NC and 125 HC.
  
  
  RESULTS
  HC had higher sNOX2-dp (25.8 ± 16.1 pg/ml) and ox-LDL (23.6 ± 14.4 U/l) levels as compared with NC (15.4 ± 10.1 and 11.6 ± 6.4 pg/ml, respectively; P < 0.001). Multiple linear regression analysis showed that ox-LDL and total cholesterol were the only independent predictive variables associated with sNOX2-dp. In NC, ox-LDL and sNOX2-dp significantly decreased from the first to the second quintile of age. In HC, ox-LDL and sNOX2-dp levels did not show significant differences among quintiles of age.
  
  
  CONCLUSIONS
  This study suggests that NOX2 contributes to generating ox-LDL during the early phase of life in NC and to the persistent high oxidative stress in the prepubertal period of HC.
authors.affiliation: I Clinica Medica, Sapienza University, Rome, Italy. lorenzo.loffredo@uniroma1.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Loffredo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Pignatelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Martino
authors.forename: Roberto
authors.initials: R
authors.lastname: Carnevale
authors.forename: Simona
authors.initials: S
authors.lastname: Bartimoccia
authors.forename: Elisa
authors.initials: E
authors.lastname: Catasca
authors.forename: Chiara
authors.initials: C
authors.lastname: Colantoni
authors.forename: Cristina
authors.initials: C
authors.lastname: Zanoni
authors.forename: Ludovica
authors.initials: L
authors.lastname: Perri
authors.forename: Francesco
authors.initials: F
authors.lastname: Violi
mesh_terms: D000367:Age Factors; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000097:blood*; D018384:Oxidative Stress
chemical_list: D008562:Membrane Glycoproteins; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases