CPT Code: 84305
Order Code: 16293
Synonyms: IGF1, Somatomedin-C, Insulin Like Growth Factor
ABN Requirement: No
Specimen: Serum
Volume: 0.5 mL
Minimum Volume: 0.3 mL
Container: Gel-barrier tube (SST)
Collection:
- Collect and label sample according to standard protocols.
- Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
- Allow blood to clot 30 minutes.
- Centrifuge for 10 minutes.
Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.
Special Instructions: Collect blood in a red-top or SST vacutainer. For red-top vacutainers, allow blood to clot (10-15 minutes) at room temperature. Separate serum from cells and refrigerate.
Stability:
Ambient (15-25°C): 48 hours
Refrigerated (2-8°C): 7 days
Frozen (-20°C): 60 days
Causes for Rejection: Moderate hemolysis
Methodology: Liquid Chromatography/Mass Spectrometry (LC/MS)
Turn Around Time: 3-6 days
Reference Range(s):
| Pediatric | Male (ng/mL) | Female (ng/mL) |
| <1 year | 14-142 | 17-185 |
| 1-1.9 years | 12-134 | 15-175 |
| 2-2.9 years | 12-135 | 16-179 |
| 3-3.9 years | 30-155 | 38-214 |
| 4-4.9 years | 28-181 | 34-238 |
| 5-5.9 years | 31-214 | 37-272 |
| 6-6.9 years | 38-253 | 45-316 |
| 7-7.9 years | 48-298 | 58-367 |
| 8-8.9 years | 62-347 | 76-424 |
| 9-9.9 years | 80-398 | 99-483 |
| 10-10.9 years | 100-449 | 125-541 |
| 11-11.9 years | 123-497 | 152-593 |
| 12-12.9 years | 146-541 | 178-636 |
| 13-13.9 years | 168-576 | 200-664 |
| 14-14.9 years | 187-599 | 214-673 |
| 15-15.9 years | 201-609 | 218-659 |
| 16-16.9 years | 209-602 | 208-619 |
| 17-17.9 years | 207-576 | 185-551 |
| Adult | ng/mL |
| 18-19.9 years | 108-548 |
| 20-24.9 years | 83-456 |
| 25-29.9 years | 63-373 |
| 30-39.9 years | 53-331 |
| 40-49.9 years | 52-328 |
| 50-59.9 years | 50-317 |
| 60-69.9 years | 41-279 |
| 70-79.9 years | 34-245 |
| >80 years | 34-246 |
| Z-Scores | -2.0 – +2.0 |
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 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 payer being billed.