IGF-I, IGFBP-3 and ALS generation test in Turner syndrome.
OBJECTIVE
The pathophysiology of the short stature in girls with Turner syndrome (TS) is not well understood. The "IGF-I generation test" is used to assess the sensitivity to growth hormone. We compared the biochemical response to four days of growth hormone of TS and controls.


METHODS
Pre-pubertal TS were recruited to participate in the study. Their siblings served as controls. IGF-I, IGFBP-3 and ALS were measured before and 5 days after using hGH (0.05mg/kg/day). Student-t test was used to compare the differences in their responses.


RESULTS
Eleven TS (mean age of 8.5+/-2.4) and 11 siblings (6 females and 5 males) (mean age of 7.0+/-2.0) participated in the study. The basal serum levels of IGF-I, IGFBP-3 and ALS were normal and not different between groups (p=0.62 for IGF-I, p=0.91 for IGFBP-3 and p=0.51 for ALS). The IGF-I generation test was positive in all controls and in 10/11 TS. The IGFBP-3 generation test was positive in 6/11 controls and 4/11 TS. After hGH the mean IGFBP-3 was lower in TS than in controls (p=0.08). The ALS response to hGH was not uniform between groups.


CONCLUSIONS
The IGF-I and ALS generation test results were not different between controls and TS. The IGFBP-3 results were higher in the control group but more than 50% of tested children did not pass. The IGF-I/IGFBP-3 generation tests, as presently done, did not help in the understanding of the short stature in TS. The use of different GH dosages and number of doses need to be investigated.
Pessoa de Queiroz
Andréa Noronha
AN
Serviço de Endocrinologia da Faculdade de Medicina, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
Collett-Solberg
Paulo F
PF
Cardoso
Monique Esteves
ME
Jusan
Rafaela Cattan
RC
Vaisman
Mario
M
Guimarães
Marília Martins
MM
D001827:Body Height; D002352:Carrier Proteins / Q000097:blood*; D002648:Child; D004392:Dwarfism / Q000097:blood / Q000209:etiology*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D019382:Human Growth Hormone / Q000008:administration & dosage*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007621:Karyotyping; D008297:Male; D014424:Turner Syndrome / Q000150:complications* / Q000235:genetics
D002352:Carrier Proteins; D006023:Glycoproteins; D018972:Insulin-Like Growth Factor Binding Protein 3; C075944:insulin-like growth factor binding protein, acid labile subunit; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I