ARUP's Laboratory Test Directory

Growth Hormone, 15 Minutes : 0070048

Mnemonic: GH 15

Methodology: Quantitative Chemiluminescent Immunoassay
Performed: Sun-Sat
Reported: 1-2 days
Specimen Required: Collect: Plasma separator tube or serum separator tube. Collect one tube per timed specimen. Also acceptable: Green (sodium or lithium heparin) or lavender (EDTA), or pink (K2EDTA).

Specimen Preparation: Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma per timed specimen to individual ARUP Standard Transport Tubes. (Min: 0.4 mL per timed specimen)

Storage/Transport Temperature: Frozen. Also acceptable: Refrigerated

Unacceptable Conditions: Tissue or urine. Grossly hemolyzed or lipemic specimens.

Stability (collection to initiation of testing): Ambient: 24 hours; Refrigerated: 1 week; Frozen: 2 months
Interpretive Data: Growth hormone stimulation tests should induce a peak of greater than 5 ng/mL in children and greater than 4 ng/mL in adults; lower values suggest growth hormone deficiency. For children, some experts consider values of 5-8 ng/mL equivocal and only peak values of greater than 8 ng/mL as truly normal.

For suppression testing, normal subjects have growth hormone concentrations of less than 0.8 ng/mL within 2 hours of ingestion of a 75 or 100 gram glucose dose. Patients with acromegaly fail to show normal suppression.
Note: This Growth Hormone assay is now standardized to the Recombinant Second International Standard (IS): 98/574. Growth hormone results read approximately 25 percent lower than with the previous standards (First IS: 80/505). Reference ranges have also been modified according to the assay manufacturer.
CPT Code(s): 83003
Cross References: Human Growth Hormone (Growth Hormone, 15 Minutes)