Test Code

CPT Codes

Preferred Specimen
0.5 mL serum

Minimum Volume
0.3 mL

For red-top tubes, allow blood to clot 10-15 minutes at room temperature. Separate serum from cells and refrigerate. If sample collected in glass collection tube, transfer to plastic container.

Transport Container
Plastic screw-cap vial

Transport Temperature
Refrigerated (cold packs)

Specimen Stability
Room temperature: 48 hours
Refrigerated: 5 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemia • Received in glass tube • Grossly icteric

Liquid Chromatography/Mass Spectrometry (LC/MS)

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Daily nights; Report available: 2-5 days

Reference Range
See Laboratory Report

Clinical Significance
Insulin-like Growth Factor 1 (IGF-1, or Somatomedin C), a protein involved in stimulating somatic growth, is regulated principally by Growth Hormone (GH) and nutritional intake. IGF-1 is transported in serum by several proteins; this helps maintain relatively high IGF-1 plasma levels and minimizes fluctuations in serum IGF-1 concentrations.
Measuring IGF-1 is useful in several growth-related disorders. Dwarfism caused by deficiency of growth hormone (Hypopituitarism) results in decreased serum levels of IGF-1, while acromegaly (growth hormone excess) results in elevated levels of IGF-1. IGF-1 measurements are also helpful in assessing nutritional status; levels are reduced in undernutrition and restored with a proper diet

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.