title: Plasma non-esterified fatty acid levels in children and their relationship with sex steroids.
abstract: OBJECTIVE
  Puberty is associated with decreased insulin sensitivity. Sexual hormones have been related with the onset of insulin resistance, but their relationship with non-esterified fatty acids (NEFA) remains unexplored. The aim of this study was to evaluate circulating NEFA levels in population-based samples of prepubertal children and adolescents and to analyze the association of NEFA with obesity, insulin resistance, and sexual hormones in adolescents.
  
  
  METHODS
  The studied population included 854 randomly selected 6-8-year-old children and 822 children aged 12-16years. NEFA levels were determined using a commercial kit. Testosterone and estradiol levels were determined by RIA, and insulin and sex hormone binding protein by IRMA. HOMA was calculated as an indicator of insulin resistance.
  
  
  RESULTS
  NEFA levels were lower in adolescents than in 6-8-year-old children, and decreased progressively with age between 12-year-olds and 16-year-olds. No significant differences in NEFA levels were observed between obese and non-obese adolescents. NEFA were not correlated with insulin or HOMA in 12-16-year-old girls, and appear negatively correlated with these variables in boys. Insulin and HOMA were negatively correlated with SHBG levels in both sexes adjusting by age but NEFA levels were not.
  
  
  CONCLUSIONS
  NEFA levels decrease with age in adolescents and are not significantly increased in obese children, supporting the fact that the decreased insulin sensitivity at this age is not affecting NEFA metabolism. Although SHBG is related to insulin and HOMA independently of age in both sexes, SHBG levels are not associated with NEFA.
authors.affiliation: Lipid Metabolism Research Laboratory, IIS-Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Ortega
authors.affiliation: Lipid Metabolism Research Laboratory, IIS-Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Garcia-Anguita
authors.affiliation: Lipid Metabolism Research Laboratory, IIS-Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Pía
authors.initials: P
authors.lastname: Riestra
authors.affiliation: Servicio de Bioquímica-Investigación, Hospital Ramón y Cajal Madrid, and CIBER de Fisiología de la Obesidad y Nutrición (CIBERobn), Spain.
authors.forename: Henar
authors.initials: H
authors.lastname: Ortega
authors.affiliation: Department of Pediatrics, IIS-Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Leandro
authors.initials: L
authors.lastname: Soriano-Guillén
authors.affiliation: Servicio de Bioquímica-Investigación, Hospital Ramón y Cajal Madrid, and CIBER de Fisiología de la Obesidad y Nutrición (CIBERobn), Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Lasunción
authors.affiliation: Lipid Metabolism Research Laboratory, IIS-Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: de Oya
authors.affiliation: Lipid Metabolism Research Laboratory, IIS-Fundación Jiménez Díaz, Madrid, Spain. Electronic address: cgarces@fjd.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcés
mesh_terms: D000293:Adolescent; D002648:Child; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000097:blood
chemical_list: D005227:Fatty Acids; D012739:Gonadal Steroid Hormones
keywords: Children; Hormone levels; Insulin; Non-esterified fatty acids; SHBG