Igf Binding Protein-3

IGF Binding Protein-3 (IGFBP-3)

What it is

The IGF Binding Protein-3 (IGFBP-3) test measures the level of IGFBP-3 in the blood. IGFBP-3 is the main carrier protein for Insulin-like Growth Factor-1 (IGF-1) in circulation and helps regulate its activity. Since IGFBP-3 levels are closely related to growth hormone (GH) activity, this test is commonly used along with IGF-1 testing to evaluate growth disorders in children and certain hormonal conditions in adults.

Uses

This test is used to:

• Assess growth hormone (GH) function in children and adults.
• Help diagnose growth disorders such as short stature, growth hormone deficiency, or gigantism/acromegaly.
• Monitor treatment with recombinant growth hormone therapy.
• Distinguish between normal growth variants and true hormonal abnormalities.
• Support evaluation of pituitary gland disorders.

Symptoms / Conditions That May Lead to the Test

Doctors may recommend this test if you or your child have:

• Poor growth or short stature compared to peers.
• Unexplained delayed or accelerated growth.
• Features of acromegaly or gigantism (large hands/feet, facial changes, rapid growth).
• Symptoms of pituitary dysfunction (headaches, vision problems, hormonal imbalance).
• Suspected growth hormone deficiency or excess.

Abnormal Results

• Low IGFBP-3 Levels: May indicate growth hormone deficiency, pituitary dysfunction, or malnutrition.
• High IGFBP-3 Levels: Can be seen in growth hormone excess (acromegaly, gigantism) or during recombinant GH therapy.

Results are interpreted together with IGF-1 levels, clinical findings, and other endocrine tests for accurate diagnosis.

Risks

The test requires a blood sample and carries minimal risks, including:

• Mild pain, bruising, or discomfort at the puncture site.
• Rare risk of infection or dizziness after blood draw.