title: Amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) predicts height velocity in healthy children.
abstract: OBJECTIVE
  C-type natriuretic peptide (CNP) is a paracrine regulatory factor of the growth plate and plays a key role in endochondral growth. Its amino-terminal propeptide (NTproCNP) is an equimolar product of CNP biosynthesis and is easily measured in plasma. Preliminary studies suggest that NTproCNP levels correlate with height velocity in sheep and children. The objectives of the study were to correlate NTproCNP levels with height velocity and to define the reference range for plasma CNP and NTproCNP across childhood.
  
  
  METHODS
  This was a prospective, cross-sectional, observational study of healthy children.
  
  
  METHODS
  Participants were 258 healthy children between 2 months and 20 years of age.
  
  
  METHODS
  Anthropometrics were obtained and CNP and NTproCNP levels were determined by radioimmunoassay.
  
  
  RESULTS
  For both sexes, CNP and NTproCNP levels were high in infancy, lower in early childhood, rising during puberty, then falling to low adult levels. Levels of NTproCNP peaked at 14·1 years in boys and 11·9 years in girls, coincident with the age of peak height velocity. Levels of NTproCNP varied with pubertal status, peaking at genital Tanner stage IV in boys and III in girls. There was a highly significant correlation between NTproCNP and height velocity.
  
  
  CONCLUSIONS
  C-type natriuretic peptide plays an integral role in endochondral growth. We show here that CNP synthesis (as measured by NTproCNP levels in plasma) is closely related to linear growth in healthy children at all ages. We propose NTproCNP as a biomarker of linear growth.
authors.affiliation: Division of Endocrinology, Nemours Children's Clinic, Jacksonville, FL 32207, USA. rolney@nemours.org
authors.forename: Robert C
authors.initials: RC
authors.lastname: Olney
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Permuy
authors.forename: Timothy C R
authors.initials: TC
authors.lastname: Prickett
authors.forename: Joan C
authors.initials: JC
authors.lastname: Han
authors.forename: Eric A
authors.initials: EA
authors.lastname: Espiner
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D001827:Body Height / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D020098:Natriuretic Peptide, C-Type / Q000097:blood*; D011446:Prospective Studies; D011627:Puberty / Q000097:blood; D011863:Radioimmunoassay; D055815:Young Adult
chemical_list: D015415:Biomarkers; C480579:amino-terminal pro-C-type natriuretic peptide, human; D020098:Natriuretic Peptide, C-Type