IGF Binding Protein-3 (IGFBP-3) Test
This test measures IGF Binding Protein-3 (IGFBP-3) in a blood sample. IGFBP-3 is the main protein that carries insulin-like growth factors I and II in the circulation, and its level responds to growth hormone activity.
About this test
IGFBP-3 binds insulin-like growth factor I and II with high affinity and carries most of the circulating IGF-I and IGF-II in the blood, though it does not bind insulin itself. Quest describes it as one of six structurally characterized IGF binding proteins and as the major carrier of circulating IGF-I and IGF-II.
Because IGFBP-3 responds to growth hormone, Quest notes that levels run high in acromegaly and low in hypopituitarism, and that levels rise in growth hormone-deficient children after growth hormone treatment begins. Levels are also reduced in poorly controlled diabetes, and Quest describes IGFBP-3 as used in assessing nutritional status, since it decreases during caloric and protein restriction.
Who might consider this test?
- Often being evaluated for a growth hormone-related condition
- Followed during growth hormone treatment in a child
- Assessed for nutritional status where a clinician wants a marker that responds to caloric and protein intake
Test details
| Quest code | 34458 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
Related tests and panels
Quest resources
Additional details
What this test looks at
The test reports the level of IGFBP-3, the carrier protein for IGF-I and IGF-II, in a serum sample. Because it is growth hormone responsive and diet responsive, a clinician reads it in the context of the specific question being asked — growth hormone status, diabetes control, or nutrition.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures IGFBP-3, the main protein that carries insulin-like growth factors I and II, in a serum sample.
How is the sample collected?
The test uses a serum sample from a routine blood draw.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
Why would IGFBP-3 be measured alongside growth hormone conditions?
Quest describes IGFBP-3 as growth hormone responsive: levels run high in acromegaly, low in hypopituitarism, and rise in growth hormone-deficient children after growth hormone treatment begins.
Can IGFBP-3 reflect nutritional status?
Quest describes IGFBP-3 as used in assessing nutritional status because levels decrease during caloric and protein restriction. A clinician reads it alongside other nutritional and clinical information.
How much does the IGF Binding Protein-3 test cost?
The cash price at Celio Health is $220. That covers the physician's order and sample collection at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.