title: Pediatric reference intervals for plasma and urine essential amino acids in a Turkish population.
abstract: OBJECTIVE
  To establish age- and sex-specific reference intervals for essential amino acids in a healthy Turkish pediatric population.
  
  
  METHODS
  A total of 945 clinically healthy children (531 boys and 414 girls, ranging in age from birth to 14 years) were enrolled. Plasma and urine amino acids' concentrations were measured by high-performance liquid chromatography.
  
  
  RESULTS
  Concentrations of essential amino acids in plasma were higher in girls than in boys in the age groups of 0-1 months and 7-14 years; however, there was no difference in the other age groups. Concentrations of essential amino acids in urine were higher in girls than in boys in the age group of 0-1 months; however, there was no difference in the other age groups. Our results demonstrated the sex-related differences in concentrations ofleucine, isoleucine, valine, phenylalanine, lysine, and histidine in plasma, which increased with age in boys but not in girls. The concentrations of leucine, tryptophan, methionine, and lysine in urine declined with age in girls but not in boys, which were sex-related differences, too.
  
  
  CONCLUSIONS
  We defined essential amino acids' reference intervals in a Turkish pediatric population.
authors.forename: Enis
authors.initials: E
authors.lastname: Macit
authors.forename: Murat
authors.initials: M
authors.lastname: Kizilgün
authors.forename: Erdinç
authors.initials: E
authors.lastname: Çakir
authors.forename: Abdulbaki
authors.initials: A
authors.lastname: Karaoğlu
authors.forename: Emin Öjzgiir
authors.initials: EÖ
authors.lastname: Akgül
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Öztosun
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Aydin
authors.forename: Fevzi Nuri
authors.initials: FN
authors.lastname: Aydin
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ağilli
authors.forename: Türker
authors.initials: T
authors.lastname: Türker
authors.forename: Recai
authors.initials: R
authors.lastname: Oğur
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Gülcan Kurt
authors.forename: Hüsamettin
authors.initials: H
authors.lastname: Gül
authors.forename: Tuncer
authors.initials: T
authors.lastname: Çayci
authors.forename: Esin
authors.initials: E
authors.lastname: Özkan
mesh_terms: D000293:Adolescent; D000601:Amino Acids, Essential / Q000097:blood* / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012016:Reference Values; D012737:Sex Factors; D014421:Turkey / Q000453:epidemiology
chemical_list: D000601:Amino Acids, Essential