Normal stimulated growth hormone secretion but low peripheral levels of insulin-like growth factor I in prepubertal children with insulin-dependent diabetes mellitus.
The hypothalamo-pituitary-insulin-like growth factor I (IGF-I) axis was studied in 24 prepubertal children with insulin-dependent diabetes mellitus (IDDM) and 12 non-diabetic children. There were no significant differences between the diabetic and control subjects in basal concentrations of immunoreactive growth hormone releasing hormone (ir-GHRH), growth hormone (GH) or stimulated GH levels, but after exercise ir-GHRH concentrations were higher in the diabetic children. Peripheral IGF-I levels were significantly lower in the diabetic children, and even lower in those with poor metabolic control. A positive correlation was found between IGF-I levels and circulating free insulin concentrations in the diabetic subjects (r = 0.49, p < 0.05). These observations suggest that the GH response to physiological stimulation is normal in prepubertal diabetic children. Exercise-induced GH response may not be mediated by GHRH. IGF-I levels were reduced in prepubertal children with IDDM and even more so in subjects with poor metabolic control. This may be a consequence of transitory hypoinsulineamia, emphasizing the importance of adequate insulinization to facilitate optimal growth in children and adolescents with IDDM.
Tapanainen
P
P
Department of Pediatrics, University of Oulu, Finland.
Käär
M L
ML
Leppäluoto
J
J
Huttunen
N P
NP
Knip
M
M
D016022:Case-Control Studies; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male
D007328:Insulin; D007334:Insulin-Like Growth Factor I; D013007:Growth Hormone-Releasing Hormone