Differential regulation of serum growth hormone (GH)-binding protein during continuous infusion versus daily injection of recombinant human GH in GH-deficient children.
Serum GH-binding protein (GHBP) was evaluated in 2 randomly divided groups of prepubertal children presenting with idiopathic GH deficiency and receiving recombinant human GH, either continuously by sc infusion (group 1) or as 1 daily sc injection (group 2). After the first 6 months, group 1 switched from continuous infusion to daily injections for the following 6 months. There was no significant difference in clinical data, GH values, or GHBP levels between the 2 groups before treatment. During the first 6 months, GHBP levels increased in all except 1 of the 8 children in group 1 from 8.6% to 16.9% after 3 months and 22.5% after 6 months. The increment factor ranged from 1.1-7.9, with wide individual variations. In group 2, the mean variation in GHBP was from 8.3-8.2% after 3 months and 10.7% after 6 months. Only 2 of the 10 children in this group showed a significant increase in GHBP levels. During the second period, group 1 maintained their GHBP levels, whereas the 2 children in group 2 tended to a continued increase in their GHBP levels. There was no correlation with the increase in growth velocity, as children in both groups grew equally well, but higher insulin-like growth factor-I levels were found in group 1, although the difference between the two groups was not significant. These data show that GH can increase GHBP levels and that there is a differential effect depending on the mode of GH administration, although the reason for and the role of such regulation remains to be explained.
Department of Pediatric Endocrinology, Purpan University Hospital, Toulouse, France.
M
M
Tauber
H
H
De Bouet Du Portal
B
B
Sallerin-Caute
P
P
Rochiccioli
R
R
Bastide
D002352:Carrier Proteins / Q000097:blood*; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage* / Q000172:deficiency* / Q000627:therapeutic use; D006801:Humans; D007260:Infusion Pumps; D007279:Injections, Subcutaneous; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D011994:Recombinant Proteins
D002352:Carrier Proteins; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; C051815:somatotropin-binding protein