title: 24-h profile of serum osteocalcin in growth hormone (GH) deficient patients with and without GH treatment.
abstract: Serum osteocalcin (OC), which is a specific, sensitive, and rapidly responding biochemical bone marker of osteoblastic activity, varies in a circadian rhythm in both normal adults and children with the highest levels during nighttime. In the present study, we characterized the 24-h rhythm of serum OC in 8 growth hormone (GH)-deficient children without treatment, and during two regimens of recombinant human GH (r-hGH), i.e. 2 IU/day s.c. at 08:00 h or at 20:00 h, in comparison with 5 normal, untreated children. Without treatment and when r-hGH was administered at 08:00 h, the 24-h profile of serum OC was correlated with that of the healthy controls in only 1 of 8 patients (r = 0.26 +/- 0.09 (mean +/- SE) and r = 0.10 +/- 0.08) whereas the correlation was significant in 6 of 8 patients (r = 0.44 +/- 0.05) during evening r-hGH administration. Within GH-deficient patients, mean OC level was lower during no r-hGH or evening administration compared with morning administration. In conclusion, untreated GH-deficient children have an abnormal 24-h serum OC profile. Evening administration of 2 IU of r-hGH/day s.c. tends to normalise the 24-h profile but not the average daily level, whereas morning administration of GH increases average daily OC level but does not normalize the circadian rhythm.
authors.affiliation: University Department of Medical Endocrinology and Metabolism, Aarhus Amtssygehus, Denmark.
authors.forename: H K
authors.initials: HK
authors.lastname: Nielsen
authors.forename: J O
authors.initials: JO
authors.lastname: Jørgensen
authors.forename: K
authors.initials: K
authors.lastname: Brixen
authors.forename: N
authors.initials: N
authors.lastname: Møller
authors.forename: P
authors.initials: P
authors.lastname: Charles
authors.forename: J S
authors.initials: JS
authors.lastname: Christensen
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002940:Circadian Rhythm; D013006:Growth Hormone / Q000008:administration & dosage / Q000172:deficiency* / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D011994:Recombinant Proteins; D015675:Osteocalcin; D013006:Growth Hormone