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Growth hormone response to hpGRF-40 in different forms of growth retardation and endocrine-metabolic diseases
Insights
Human pancreatic growth hormone releasing factor (hpGRF-40) effectively stimulates growth hormone (GH) release in normal children. It also helps assess GH function in various growth disorders, though responses vary.
Area of Science:
- Pediatric Endocrinology
- Hormone Research
- Growth Disorders
Background:
- Growth hormone (GH) deficiency is a significant cause of growth retardation in children.
- Human pancreatic growth hormone releasing factors (hpGRFs) are newly identified hormones with potential diagnostic applications.
- Assessing GH secretory capacity is crucial for diagnosing and managing growth impairments.
Purpose of the Study:
- To evaluate the efficacy of synthetic hpGRF-40 as a diagnostic tool for GH deficiency.
- To investigate the GH response to hpGRF-40 in children with various endocrine-metabolic diseases and growth retardation.
- To compare hpGRF-40's effect in normal children versus those with growth impairments.
Main Methods:
- Intravenous administration of synthetic hpGRF-40 (1 microgram/kg) to participants.
- Measurement of plasma growth hormone (GH) levels before and after hpGRF-40 administration.
- Inclusion of normal prepubertal children, children with isolated GH deficiency (IGHD), Silver-Russell syndrome, craniopharyngioma, constitutional growth delay (CGD), hypothyroidism, and idiopathic obesity.
Main Results:
- hpGRF-40 induced a significant GH rise in normal children and those with IGHD and Silver-Russell syndrome.
- Limited or no GH response was observed in children with craniopharyngioma.
- A defective, albeit biphasic, GH response to hpGRF-40 was noted in children with CGD, even with normal responses to other stimuli. Hypothyroid subjects showed a sustained GH rise, while those with obesity had a reduced response.
Conclusions:
- Synthetic hpGRF-40 is a potent stimulator of GH release in normal prepubertal children.
- hpGRF-40 serves as a valuable physiological tool for investigating GH function in pediatric growth disorders.
- The varying responses highlight hpGRF-40's utility in differentiating causes of growth impairment and assessing GH secretory capacity.
Abstract:
The effect of one of the new human pancreatic growth hormone releasing factors (hpGRFs) was assessed in children or young adults with different forms of growth retardation or endocrine-metabolic diseases. Intravenously administered synthetic hpGRF-40 (1 microgram/kg) induced a clear-cut and prompt rise in plasma growth hormone (GH) levels in 8 normal prepubertal children and a definite GH rise in 11 out of 14 children with isolated GH deficiency (IGHD) and one child with the Silver-Russel syndrome. In two out of three subjects with craniopharyngioma hpGRF-40 did not induce any plasma GH increase. In seven out of ten children with constitutional growth delay (CGD), hpGRF-40 induced a biphasic GH response, with a prompt small GH increment followed by a second, more consistent rise. Both in children with IGHD and with CGD the rise in plasma GH following hpGRF-40 was markedly lower than in controls. In children with CGD the GH response to hpGRF-40 was defective, despite the fact that in most of them the GH response to standard pharmacological stimuli was normal according to generally accepted criteria. hpGRF induced a small but sustained plasma GH rise in four hypothyroid subjects, while in three out of four children with idiopathic obesity the GH response to hpGRF was strikingly reduced. These data demonstrate that hpGRF is a potent stimulus of GH release in normal prepubertal children and a physiological means of investigating GH function in diseases associated with growth impairment.