Dynamics of bone turnover in children with GH deficiency treated with GH until final height.
OBJECTIVE
To examine the dynamics of bone turnover in children with growth hormone deficiency (GHD) during long-term treatment.


METHODS
We longitudinally measured growth velocity and serum concentrations of osteocalcin (OC), carboxyterminal propeptide of type I procollagen (PICP), and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) in 24 patients with GHD during long-term GH treatment until final height (age: 7.7+/-0.7 and 16.9+/-0.5 years at baseline and at final height respectively).


RESULTS
At baseline, OC, PICP, and ICTP levels were significantly (P<0.0001) reduced in comparison with prepubertal bone age-matched controls (10.2+/-2.3 microgram/l and 22.5+/-7.6 microgram/l; 187.8+/-26.2 microgram/l and 328. 4+/-74.3 microgram/l; 7.7+/-2.0 microgram/l and 14.2+/-1.3 microgram/l respectively). During the first year of treatment mean levels of the bone markers increased significantly (P<0.0001) with a peak at 12 months. After the first year of treatment, OC and PICP levels progressively declined, whereas ICTP levels remained stable until the final height; in any case, bone marker levels remained significantly higher (P<0.03-P<0.0001) than baseline. The change in bone marker levels at 6 and 12 months of treatment with respect to the baseline values was not related to growth rate during long-term treatment or final height.


CONCLUSIONS
The results show that children with GHD have reduced bone turnover at baseline, and that long-term GH treatment is associated with a stimulation of bone turnover. OC, PICP, and ICTP do not predict growth rate during long-term treatment or final height in children with GHD.
Baroncelli
G I
GI
Endocrine Unit, Division of Pediatrics, Department of Reproductive Medicine and Pediatrics, University of Pisa, Pisa, Italy.
Bertelloni
S
S
Ceccarelli
C
C
Cupelli
D
D
Saggese
G
G
D000293:Adolescent; D001827:Body Height / Q000187:drug effects*; D016723:Bone Remodeling; D003094:Collagen / Q000097:blood; D024042:Collagen Type I; D005260:Female; D013006:Growth Hormone / Q000172:deficiency* / Q000627:therapeutic use*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000097:blood; D011347:Procollagen / Q000097:blood
D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; D013006:Growth Hormone; D003094:Collagen