Somatomedin C (IGF-1)

Test Code

SOM

Alias/See Also

Somatomedin-C
Insulin-Like Growth Factor (IGF-1)

Quest Code
16293

CPT Codes
84305

Preferred Specimen

0.5 mL serum collected in no additive (red-top) tube

Minimum Volume

0.3 mL

Transport Temperature

Refrigerated

Specimen Stability

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

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis, lipemia, or icterus
Received in glass tube

Methodology
Liquid Chromatography / Mass Spectrometry (LC/MS) This test was developed and its performance characteristics were determined by Quest Diagnostics Nichols Institute. Performance characteristics refer to the analytical performance of the test.

Setup Schedule

Monday-Friday, Sunday p.m.

Report Available

5 days

Clinical Significance

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

Performing Laboratory
Quest Diagnostics Nichols Institute
San Juan Capistrano, CA

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.