Summary of IGFBP-3: Biological Functions and Clinical Application Value

Hits:17   Date: 11/5/2026

IGFBP3 is the most abundant insulinlike growth factor–binding protein in human postnatal blood and a core component of the GHIGF axis. It regulates IGF bioactivity, stability, and distribution, with important physiological roles and high clinical value.

1. Core Biological Characteristics
· Mainly secreted by the liver; molecular weight ~40–45 kDa.
· Highly conserved structure with specific IGFbinding domains.
· Forms stable complexes with IGFI/IGFII to modulate signaling.

2. Key Biological Functions
01. Protects IGFs from degradation
Extends IGF halflife and maintains circulating activity.
02. Mediates IGF transport
Carries IGFs to target tissues and supports tissuespecific delivery.
03. Bidirectionally regulates IGF–receptor interaction
Can either inhibit or enhance IGF signaling based on physiological conditions.

3. Relationship with Growth Hormone (GH)
· Serum IGFBP3 is GHdependent.
· GH stimulates hepatic synthesis of IGFI and IGFBP3.
· IGFBP3 levels reflect GH secretion status.

4. Major Clinical Applications
01. Screening for abnormal GH secretion
· Low levels: GH deficiency
· High levels: Acromegaly
02. Diagnosis of childhood primary IGF deficiency
Supports identification of children with low IGFI but normal GH; simpler and more reproducible than GH stimulation tests.

5. Conclusion and Prospects
IGFBP3 is essential for growth, development, and metabolic regulation. It serves as a reliable biomarker for GH and IGFrelated disorders. Future studies will further clarify its mechanism, expand its clinical use, and explore its potential as a therapeutic target.