Reduced insulin growth factor I concentrations in iron-overloaded beta thalassaemic patients with normal growth hormone secretion and liver function.
We selected 92 subjects (46 females and 46 males), aged 10-15 years, from the Haematology and Endocrine Clinic of Shiraz University, Iran. Forty-six were beta thalassaemia patients (beta-Th) with short stature, 23 had idiopathic short stature (ISS) and 23 were healthy children with a standing height between the 10th and 95th percentile. Growth hormone (GH) secretion was normal in 23 beta-Th patients and reduced in the remaining 23 patients. A low insulin growth factor I (IGF-I) was found in 73.9% of beta-Th patients with GH deficiency, 56.5% of beta-Th patients with normal GH secretion to stimulation test and 8.7% of children with ISS. The reduced IGF-I concentration in beta-Th patients with normal GH secretion may be explained by partial insensitivity to GH (GHIS), neurosecretory dysfunction, low bioactive GH or increased proportion of circulating, non-22-kDa GH isoform. The possibility of GHIS in beta-Th patients with short stature indicates that higher doses of rechGH may be required to obtain an improvement in growth velocity in beta-Th patients.
Karamifar
Hamdollah
H
Endocrine Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. karimim@sums.ac.ir
Karimi
Mehran
M
Amirhakimi
Gholamhossein
G
Sharbatialaei
Mohammadreza
M
De Sanctis
Vincenzo
V
D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D003676:Deferoxamine / Q000494:pharmacology; D005260:Female; D005293:Ferritins / Q000097:blood; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D019190:Iron Overload / Q000201:enzymology / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D017086:beta-Thalassemia / Q000097:blood / Q000201:enzymology / Q000378:metabolism*
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D005293:Ferritins; D000410:Alanine Transaminase; D003676:Deferoxamine