title: Strong Associations Exist among Oxidative Stress and Antioxidant Biomarkers in the Circulating, Cellular and Urinary Anatomical Compartments in Guatemalan Children from the Western Highlands.
abstract: BACKGROUND
  A series of antioxidant enzymes and non-enzymatic compounds act to protect cells from uncontrolled propagation of free radicals. It is poorly understood, though, to what extent and how their interaction is harmonized.
  
  
  OBJECTIVE
  To explore associative interactions among a battery of urinary and blood biomarkers of oxidative stress and enzymatic and non-enzymatic markers of the antioxidant defense system in children from low income households.
  
  
  METHODS
  For this cross-sectional descriptive study, urine, red cells, and plasma were sampled in 82 preschool children attending three daycare centers in Quetzaltenango Guatemala. The urinary oxidative stress biomarkers studied were F2-isoprostanes and 8-hydroxy-deoxy-guanosine. Red cell enzyme activities measured were: catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Circulating non-enzymatic antioxidants selected were: retinol, tocopherols, β-carotene and coenzymes Q9 and Q10.
  
  
  RESULTS
  In a Spearman rank-order correlation hemi-matrix, of 55 paired combinations of the 11 biomarkers, 28 (51%) were significantly correlated among each other (p ≤ 0.05), with the strongest association being retinol and tocopherols (r = 0.697, p<0.001), and 4 associations (9%) showed a trend (p> 0.5 to ≤ 0.10). F2-isoprostanes showed the greatest number of cross-associations, having significant interactions with 8 of the 10 remaining biomarkers. Goodness-of-fit modeling improved or maintained the r value for 24 of the significant interactions and for one of the 5 borderline associations. Multiple regression backward stepwise analysis indicated that plasma retinol, β-carotene and coenzyme Q10 were independent predictors of urinary F2-isoprostanes.
  
  
  CONCLUSIONS
  Numerous significant associations resulted among biomarkers of oxidation and responders to oxidation. Interesting findings were the apparent patterns of harmonious interactions among the elements of the oxidation-antioxidation systems in this population.
authors.affiliation: Center for the Studies of Sensory Impairment, Aging, and Metabolism-CeSSIAM-Guatemala City, Guatemala.
authors.forename: María J
authors.initials: MJ
authors.lastname: Soto-Méndez
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center for Biomedical Research, University of Granada, Granada, Spain.|Networking Biomedical Research for Obesity and Nutrition-CIBERobn-, Madrid, Spain.
authors.forename: Concepción M
authors.initials: CM
authors.lastname: Aguilera
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center for Biomedical Research, University of Granada, Granada, Spain.|Thematic Networks of Cooperative Research-RETIC-, Carlos III Health Institute-ISCIII-, General Sub-Directorate for Research Assessment and Promotion and the European Regional Development Fund-ERDF-ref. RD12/0026, Madrid, Spain.
authors.forename: María D
authors.initials: MD
authors.lastname: Mesa
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center for Biomedical Research, University of Granada, Granada, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Campaña-Martín
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center for Biomedical Research, University of Granada, Granada, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Martín-Laguna
authors.affiliation: Center for the Studies of Sensory Impairment, Aging, and Metabolism-CeSSIAM-Guatemala City, Guatemala.
authors.forename: Noel W
authors.initials: NW
authors.lastname: Solomons
authors.affiliation: Molecular Nutrition Unit, ZIEL, Research Center for Nutrition and Food Science, Technische Universität München, Freising, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Schümann
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center for Biomedical Research, University of Granada, Granada, Spain.|Networking Biomedical Research for Obesity and Nutrition-CIBERobn-, Madrid, Spain.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Gil
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003848:Deoxyguanine Nucleotides / Q000097:blood / Q000652:urine; D028441:F2-Isoprostanes / Q000097:blood / Q000652:urine; D005260:Female; D006166:Guatemala; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000097:blood*; D012959:Socioeconomic Factors
chemical_list: C521293:8-hydroxy-2'-deoxyguanosine 5'-triphosphate; D000975:Antioxidants; D015415:Biomarkers; D003848:Deoxyguanine Nucleotides; D028441:F2-Isoprostanes; D000080242:8-Hydroxy-2'-Deoxyguanosine; D010088:Oxidoreductases