Evaluating the IGF-1 generation test as a predictor of growth outcomes across pediatric growth disorders"

Fawzia Alyafei; Ahmed Elawwa; Aml Sabt; Shayma Ahmed; Nada Alaaraj; Noor Hamed; Ashraf Soliman

doi:10.1530/endoabs.110.EP830

JOINT510

Background: IGF-1 generation is valuable for assessing early and long-term growth outcomes, but its utility varies depending on the disorder and degree of GH sensitivity.

Objective of the Review: To evaluate the predictive and diagnostic significance of the IGF-1 generation-test in determining growth response and GH sensitivity in growth disorders.

Methods: Data were compiled from six studies, encompassing over 800 pediatric patients with conditions such as Growth Hormone Deficiency (GHD), Idiopathic Short Stature (ISS), and GH insensitivity. Studies assessed the correlation between IGF-1 generation, early IGF-1 responses during GH therapy, and long-term growth outcomes.

Results: Table. 1. Predictive Value: Early increases in IGF-1 levels during GH therapy strongly correlated with positive long-term growth outcomes, as highlighted by studies with larger sample sizes-(Smyczynski et al., 2013; Blum et al., 1993).

2. GH Sensitivity: Changes in IGF-1 levels during therapy positively correlated with improvements in height, confirming GH sensitivity across various conditions-(Kim et al., 2021).

3. Utility in Diagnosing GH Insensitivity: The test has limitations in detecting mild GH insensitivity, with some variability in responses among GHD and ISS patients-(Coutant et al., 2012; Buckway et al., 2001).

4. Combined Markers: IGFBP-3 levels at baseline and during therapy enhance the predictive utility of the test, particularly in short stature children-(Perez-Colon et al., 2018).

Discussion: The IGF-1 generation test is a valuable tool for predicting long-term growth responses to GH therapy and assessing GH sensitivity. Its strengths lie in strong early correlations with growth outcomes, but its limitations in detecting mild GH insensitivity highlight the need for additional markers like IGFBP-3.

Table 1.
Condition	Main Findings
Short Stature and GHD	Early IGF-1 and IGFBP-3 increases correlate with long-term growth response to GH therapy.
GHD and ISS	Early IGF-1 increases predict better growth outcomes over time.
Short Stature (Various Conditions)	Positive IGF-1 changes during therapy correlate with height improvement.
Mild GH Insensitivity (GHIS)	Test has limitations in detecting mild GH insensitivity.
GH Responsiveness (GHD, ISS, GHIS)	GH sensitivity varies; IGF-1 generation test reflects dose-dependent response.
Short Stature with Low IGF-1	Baseline IGF-1 and IGFBP-3 predict growth response to GH or IGF-1 therapy.

Conclusions: The IGF-1 generation test is a reliable marker for predicting GH therapy outcomes and assessing GH sensitivity in children. Its utility is enhanced when combined with additional biomarkers like IGFBP-3, although limitations in diagnosing mild GH insensitivity must be considered. Table: Predictive and Diagnostic Findings from IGF-1 Generation Test Across Growth Conditions"

Endocrine Abstracts

EP830