['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.', 'This was a prospective, cross-sectional, observational study of healthy children.', 'Participants were 258 healthy children between 2\xa0months and 20\xa0years of age.', 'Anthropometrics were obtained and CNP and NTproCNP levels were determined by radioimmunoassay.', '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\xa0years in boys and 11·9\xa0years 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.'] Does amino-terminal propeptide of C-type natriuretic peptide ( NTproCNP ) predict height velocity in healthy children?