title: Parathyroid Hormone Levels in Healthy Children and Adolescents.
abstract: BACKGROUND
  Parathyroid hormone (PTH) is important in the assessment of calcium metabolism disorders. However, there are few data regarding PTH levels in childhood and adolescence.
  
  
  OBJECTIVE
  The aim of this study was to determine PTH levels in a large group of healthy children and adolescents.
  
  
  METHODS
  We retrospectively evaluated PTH levels in 1,580 healthy Caucasian children and adolescents (849 females, 731 males, aged 2.0-17.2 years) with 25-hydroxyvitamin D [25(OH)D] levels ≥ 30 ng/ml. All subjects with genetic, endocrine, hepatic, renal, or other known diseases were excluded.
  
  
  RESULTS
  The serum intact PTH concentration (median and inter-quartile range) was 23.00 (15.00-31.60) pg/ml. In our population, the mean 25(OH)D value was 34.27 ± 4.12 ng/ml. The median PTH concentration in boys was 23.00 (15.00-32.00) pg/ml, whereas in girls it was 23.10 (15.00-31.10) pg/ml. However, in girls, PTH levels significantly increased in the age group of 8.1-10.0 years compared to the age group of 2.1-4.0 years (p < 0.0001), whereas in boys it significantly increased in the age groups of 10.1-12.0 years (p < 0.0001) and 12.1-14.0 years (p < 0.0001), leading to the hypothesis of a relationship between PTH level and pubertal and bone growth spurts.
  
  
  CONCLUSIONS
  PTH levels in healthy children and adolescents covered a narrower range than the adult values. Obtaining reference values of PTH in childhood and adolescence could aid in the estimation of appropriate values of bone metabolites.
authors.affiliation: Health Sciences Department, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Stagi
authors.forename: Loredana
authors.initials: L
authors.lastname: Cavalli
authors.forename: Silvia
authors.initials: S
authors.lastname: Ricci
authors.forename: Marina
authors.initials: M
authors.lastname: Mola
authors.forename: Cinzia
authors.initials: C
authors.lastname: Marchi
authors.forename: Salvatore
authors.initials: S
authors.lastname: Seminara
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Brandi
authors.forename: Maurizio
authors.initials: M
authors.lastname: de Martino
mesh_terms: D000293:Adolescent; D000375:Aging / Q000378:metabolism; D001846:Bone Development / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D007223:Infant; D007558:Italy; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood* / Q000502:physiology; D011627:Puberty / Q000502:physiology; D012016:Reference Values; D012189:Retrospective Studies; D012727:Sex Characteristics; D044465:White People
chemical_list: D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone