title: Plasma levels and redox status of coenzyme Q10 in infants and children.
abstract: BACKGROUND
  Increased attention has been paid to the role of lipophilic antioxidants in childhood nutrition and diseases during recent years. The lipophilic antioxidant coenzyme Q10 (CoQ10) is known as an effective inhibitor of oxidative damage. In contrast to other lipophilic antioxidants like alpha-tocopherol the plasma concentrations of CoQ10 in childhood are poorly researched. The aim of this study was to determine plasma level and redox status (oxidized form in total CoQ10 in %) of CoQ10 in clinically healthy infants, preschoolers and school-aged children.
  
  
  METHODS
  Plasma level and redox status of CoQ10 were measured by HPLC in 199 clinically healthy children, three groups of infants [1st-4th month (n = 35), 5th-8th month (n = 25), 9th-12th month (n = 25) ], preschoolers (n = 60) and school-aged children (n = 54). The CoQ10 plasma levels were related to plasma cholesterol concentrations. The median and the 5th and 95th percentile were calculated.
  
  
  RESULTS
  Plasma levels and redox status of CoQ10 in infants were significantly higher than in preschoolers and school-aged children. The CoQ10 redox status in the 1st-4th month was significantly increased when compared to the remaining subgroups of infants. In elder children the CoQ10 redox status stabilized.
  
  
  CONCLUSIONS
  This is the first study concerning age-related values of plasma level and redox status of CoQ10 in apparently healthy children. Decreased CoQ10 values could be involved in various pathological conditions affecting childhood. Therefore, the application of age-adjusted reference values may provide more specific criteria to define threshold values for CoQ10 deficiency in plasma.
authors.affiliation: Vestische Kinderklinik Datteln, Universität Witten/ Herdecke, Dr.-Friedrich-Steiner-Str. 5, D-45711 Datteln, Germany. th.menke@t-online.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Menke
authors.forename: Petra
authors.initials: P
authors.lastname: Niklowitz
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schlüter
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Dirk
authors.initials: D
authors.lastname: Buschatz
authors.forename: Eckardt
authors.initials: E
authors.lastname: Trowitzsch
authors.forename: Werner
authors.initials: W
authors.lastname: Andler
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000975:Antioxidants / Q000378:metabolism*; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D002784:Cholesterol / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010084:Oxidation-Reduction; D012016:Reference Values; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D003067:Coenzymes; D014451:Ubiquinone; D002784:Cholesterol; C024989:coenzyme Q10