Final height in patients with idiopathic short stature and high growth hormone responses to stimulation tests.
Children with idiopathic short stature (ISS) may have normal or increased growth hormone (GH) responses to provocation tests and achieve a final height (FH) below -2.0 standard deviation score (SDS) if untreated. FH of subjects with high stimulated GH levels has not been studied in detail.


OBJECTIVE
It was the aim of this study to analyse FH in ISS patients with high GH peak responses to the provocation test.


METHODS
We studied 16 patients (9 pre-pubertal) with ISS and a GH peak >or=40 mU/l to insulin-induced hypoglycaemia. The patients were recalled at age 19.7 +/- 2.5 years for measurement of FH when blood samples were obtained for serum insulin-like growth factor (IGF)-I, IGF binding protein 3, acid-labile subunit and GH binding protein measurements. GH bioactivity was determined using the Nb2 bioassay.


RESULTS
FH was -3.1 +/- 1.0 SDS, being significantly lower than target height (TH). At FH, IGF-I levels were within -1.5 and +1.5 SDS for age and sex in 10 patients and higher than +1.5 SDS in 6 patients. IGF binding protein 3, acid-labile subunit, GH binding protein levels and GH bioactivity values were normal.


CONCLUSIONS
These data suggest that patients with ISS and high GH levels during a GH stimulation test may have a more compromised FH. The association of severe ISS with a peak GH >40 mU/l might suggest a degree of insensitivity for the GH-IGF-I axis.
Martinelli
Carlos Eduardo
CE
Department of Paediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil. cemart@fmrp.usp.br
Sader Milani
Soraya
S
Previato
Joana Karin
JK
Figueira
Marcos
M
Rangel Montenegro
Ana Paula
AP
Miraki-Moud
Farideh
F
Betancourth
Sandra
S
Moreira
Ayrton Custódio
AC
Savage
Martin O
MO
Camacho-Hübner
Cecilia
C
D000293:Adolescent; D000328:Adult; D001827:Body Height; D002352:Carrier Proteins / Q000097:blood; D002648:Child; D005260:Female; D006023:Glycoproteins / Q000097:blood; D006130:Growth Disorders / Q000097:blood* / Q000503:physiopathology; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D008297:Male; D010375:Pedigree; D010901:Pituitary Function Tests; D011627:Puberty / Q000502:physiology
D002352:Carrier Proteins; D006023:Glycoproteins; D018969:Insulin-Like Growth Factor Binding Proteins; C075944:insulin-like growth factor binding protein, acid labile subunit; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; C051815:somatotropin-binding protein