title: Associations between adiposity and indicators of thyroid status in children and adolescents.
abstract: BACKGROUND
  In adults, obesity is associated with abnormalities of thyroid function; there are fewer studies in paediatric cohorts.
  
  
  OBJECTIVE
  To examine associations of weight and adiposity with indices of thyroid function and thyroid-related metabolic factors in children.
  
  
  METHODS
  A sample of 1203 children without obesity (body mass index [BMI] < 95th percentile; N = 631) and with obesity (BMI ≥ 95th percentile; N = 572), age 5-18 years, had height and weight measured (to calculate BMI-Z score for age and sex) and had blood collected in the morning for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and leptin. A subset (N = 829) also underwent measurement of fat mass by dual-energy X-ray absorptiometry. Analyses examined associations of TSH and FT4 with adiposity and obesity-related conditions accounting for sociodemographic factors.
  
  
  RESULTS
  Thyroid-stimulating hormone was positively related to BMIz and fat mass (both p-values < 0.001). FT4 was negatively related to BMIz and fat mass (both p-values < 0.001). TSH was positively correlated to leptin (p = 0.001) even after accounting for fat mass.
  
  
  CONCLUSIONS
  Paediatric obesity is associated with higher TSH and lower FT4 concentrations and with a greater prevalence of abnormally high TSH. Leptin concentrations may in part explain obesity's effects on thyroid status, perhaps through leptin's effects on TSH secretion.
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.|NIH Division of Nutrition Research Coordination, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Krause
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: B
authors.initials: B
authors.lastname: Cines
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: E
authors.initials: E
authors.lastname: Pogrebniak
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: R
authors.initials: R
authors.lastname: Sherafat-Kazemzadeh
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Demidowich
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: O A
authors.initials: OA
authors.lastname: Galescu
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Brady
authors.affiliation: Division of Nuclear Medicine, Radiology and Imaging Sciences Department, Hatfield Clinical Center, NIH, Bethesda, MD, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Reynolds
authors.affiliation: NIH Division of Nutrition Research Coordination, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Hubbard
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Yanovski
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D063766:Pediatric Obesity / Q000503:physiopathology*; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*
chemical_list: D020738:Leptin; D013972:Thyrotropin; D013974:Thyroxine
keywords: Free thyroxine; TSH; obesity; paediatric