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Growth and somatomedin-C responses to growth hormone in dwarfed children
Insights
Short stature in children can be diagnosed using growth hormone (GH) therapy response. Testing Sm-C levels and growth increments after GH treatment helps identify children who will benefit from long-term therapy.
Area of Science:
- Pediatrics
- Endocrinology
- Growth Disorders
Background:
- Short stature is a common concern in pediatric endocrinology.
- Insulin-like growth factor 1 (IGF-1), also known as somatomedin-C (Sm-C), plays a crucial role in growth.
- Assessing the response to growth hormone (GH) therapy is vital for managing growth deficiencies.
Purpose of the Study:
- To evaluate the effectiveness of short-term exogenous growth hormone (GH) therapy in classifying children with short stature.
- To determine if Sm-C levels and growth increments in response to GH therapy can predict long-term treatment benefits.
- To differentiate between GH insufficiency, biologically inactive GH, and Laron-type dwarfism.
Main Methods:
- Nineteen children with short stature and low Sm-C levels received a ten-day course of exogenous GH therapy.
- Patients were classified into three groups based on endogenous GH levels and their response to GH therapy (Sm-C and height velocity).
- Group I: GH insufficiency with blunted GH response, normalized Sm-C and growth velocity with therapy.
- Group II: Normal GH response to stimulation, but similar response to exogenous GH as GH deficient subjects.
- Group III: Normal endogenous GH release, but no increase in Sm-C or growth rate with GH therapy.
Main Results:
- Group I patients showed a positive response to GH therapy, indicating GH insufficiency.
- Group II patients, despite normal GH stimulation tests, responded to exogenous GH, suggesting potentially inactive GH.
- Group III patients did not respond to GH therapy, consistent with Laron-type dwarfism.
Conclusions:
- Short-term exogenous GH therapy response, measured by Sm-C levels and growth increments, is a more precise indicator for long-term GH therapy suitability than plasma GH response to stimulation.
- This approach helps differentiate between various causes of short stature, including GH deficiency, biologically inactive GH, and Laron-type dwarfism.
- Accurate classification guides optimal therapeutic strategies for children with growth disorders.
Abstract:
Nineteen children were studied because of short stature. They had in common abnormally low Sm-C values for age, and each received a ten-day course of exogenous GH therapy. Based on their endogenous GH concentrations and the response to GH therapy, in terms of Sm-C and height increments, they were classified into three groups. Group I included patients with GH insufficiency who had blunted GH responses to stimulation, but responded to therapy by normalizing the Sm-C concentration and velocity of growth. Group II patients all had normal GH responses to stimulation, but their responses to exogenous GH were similar to those observed in the GH deficient subjects. In the two children in Group III who had normal release of endogenous GH, Sm-C values and growth rate did not increase in response to GH. Group II patients may represent children with biologically inactive but immunoreactive GH, whereas the children in Group III are examples of the Laron type of dwarfism. Thus, rather than the plasma GH response to provocative stimuli, the Sm-C and growth increment responses to short-term exogenous GH therapy may more precisely identify children that will benefit from long-term GH therapy.