[Usefulness of the measurement of insulin-like growth factor (IGF-I) and IGF-1 binding protein-3 (IGFBP-3) for the diagnosis of growth hormone (GH) deficiency in children].
BACKGROUND
The diagnosis of GH deficiency (GHD) is based upon the results of GH stimulation tests, which have several drawbacks.


OBJECTIVE
To evaluate the usefulness of IGF-1 and IGFBP-3 for the diagnosis of GHD in prepuberal children.


METHODS
We measured IGF-I and IGFBP-3 in three group of subjects: I. GHD (n: 24), height < -2SD for age (Z score, average +/- SD: -4.2 +/- 1.2), growth velocity < p10 (3.4 +/- 1.0 cm/year) and peak GH level on two GH stimulation tests < 7 ng/ml (1.2 +/- 0.6 ng/ml); II. Short non-GHD (NGHD, n: 32), height of -2.7 +/- 0.9 SD for age, growth velocity < p 25 (3.9 +/- 1.2 cm/year), and peak GH level on two GH stimulation tests > 7 ng/ml (15.3 +/- 6.9 ng/ml), y III. Normal school children (n: 35) with normal heights (-0.17 +/- 0.12 SD) were studied as controls.


RESULTS
IGF-1 and IGFBP-3 were significantly lower in GHD than in NGHD and controls (p < 0.001), and in NGHD than in C (p < 0.001). We defined the normal range of both proteins as +/- 2 SD of the mean of the control group. Using this criteria, IGF-I was low in 21/24 GHD, and in 12/32 NGHD. IGFBP-3 was low in 22/24 GHD, and in 6/32 NGHD. Only 1 GHD patient had both exams in the normal range, suggesting that he is probably NGHD. 4/32 of the NGHD and both exams below normal range, suggesting that they are probably GHD.


CONCLUSIONS
IGF-1 and IGFBP-3 are important tools for the diagnosis of GHD.
Codner
E
E
Instituto de Investigaciones Materno Infantil, Universidad de Chile.
Méricq
V
V
Ugarte
F
F
Iñíguez
G
G
Espinoza
M
M
Avila
A
A
Salazar
T
T
Cassorla
F
F
García
H
H
D002648:Child; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis*; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male
D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I