IGF-I (Insulin-Like Growth Factor 1), LC/MS : 16293

IGFI or 16293

Somatomedin-C; Insulin-Like Growth Factor; IGF-1

Serum separator tube or plain red top tube.

Centrifuge the separator tube and transport. If plain red top tube allow to clot 10-15 minutes, then centrifuge and alquot serum into a standard transport tube, 0.5 mL (Min: 0.3 mL).

Refrigerated.

After separation from cells: Ambient: 48 hours; Refrigerated: 7 days; Frozen: 60 days

Moderate hemolysis.

Sunday - Saturday

1-4 days (From receipt at performing laboratory)

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.

Pediatric Ranges IGF-1, LC/MS                            Male (ng/mL)    Female (ng/mL) less than 1 Years:     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 Ranges IGF-1, LC/MS: 18-19.9 Years:    108-548 ng/mL 20-24.9 Years:    83-456   ng/mL 25-29.9 Years:    63-373   ng/mL 30-39.9 Years:    53-331   ng/mL 40-49.9 Years:    52-328   ng/mL 50-59.9 Years:    50-317   ng/mL 60-69.9 Years:    41-279   ng/mL 70-79.9 Years:    34-245   ng/mL greater than 80 Years:    34-246   ng/mL      Z-Score (Male):   -2.0 - +2.0 SD Z-Score (Female):    -2.0 - +2.0 SD

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.