Bioactive IGF-I Concentrations in Children on GH Therapy

Area of Science:

• Pediatric Endocrinology
• Growth Hormone Therapy
• Biomarker Analysis

Background:

• Monitoring Insulin-like Growth factor (IGF)-I is crucial during Growth Hormone (GH) therapy in children.
• Elevated total IGF-I levels raise concerns about potential long-term health risks.

Purpose of the Study:

• To compare bioactive and total IGF-I levels in healthy children and adolescents.
• To evaluate bioactive and total IGF-I in children undergoing GH therapy.

Main Methods:

• Established pediatric, sex-specific reference ranges for bioactive IGF-I (KIRA).
• Compared bioactive IGF-I with total IGF-I, IGF-I/IGFBP-3 molar ratio (iSYS), and IGF-I, -II, IGFBP-3, ALS (LC-MS/MS).
• Assessed IGF-I bioactivity relative to total IGF-I during GH therapy.

Main Results:

• Bioactive IGF-I positively correlated with total IGF-I and IGF-I/IGFBP-3 in healthy children.
• Bioactive IGF-I showed negative correlation with IGF-II.
• A smaller proportion of GH-treated patients had elevated bioactive IGF-I compared to total IGF-I.

Conclusions:

• Bioactive IGF-I levels were within reference ranges for most children receiving GH therapy.
• Monitoring bioactive IGF-I may aid in optimizing GH dosing for specific pediatric patient subgroups.