The usefulness of the GHRH stimulation test in the diagnostics of growth hormone deficiency in children.
BACKGROUND
Stimulation tests form the basis for the diagnostic process in growth hormone deficiency (GHD). One of these tests uses the GH releasing hormone (GHRH). This provides the potential to differentiate patients with pituitary dysfunction from patients with hypothalamus abnormalities. However, the routine use of the GHRH test is still being debated. The aim of this study was to assess the diagnostic usefulness of the GHRH test in the diagnostics of GHD.


METHODS
The study group consisted of 20 prepubertal children with GHD. In all the children, one of the performed stimulation tests was the GHRH test.


RESULTS
The results showed that the mean peak concentration of GH in the GHRH test was 14.7 ± 11.3 ng/mL. In eight children the MRI showed pituitary hypoplasia, in one patient pituitary hypoplasia and pituitary stalk agenesis, and in one patient septo-optic dysplasia. All patients with pituitary malformations, except for one patient with a hypoplastic pituitary gland, presented GH levels < 10 ng/mL in the GHRH test. The sensitivity of the GHRH test in the diagnostics of GHD was 45%.


CONCLUSIONS
The high correlation between the GHRH test and anatomical changes in the pituitary provides this test with a high predictive value. In individual clinical cases, knowledge about the level of damage in the hypothalamic-pituitary area can determine diagnostic and therapeutic procedures.
Department of Paediatric Endocrinology and Rheumatology, Poznan University of Medical Sciences. m.moszynska@ump.edu.pl.
Monika
M
Obara-Moszyńska
Marek
M
Niedziela
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D013007:Growth Hormone-Releasing Hormone; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010900:Pituitary Diseases / Q000175:diagnosis*; D010901:Pituitary Function Tests; D012680:Sensitivity and Specificity
D019382:Human Growth Hormone; D013007:Growth Hormone-Releasing Hormone