Growth Hormone, 30 Minutes

Casandra

Casandra Test Code AR43734Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0070082CPT Code 83003

Growth Hormone, 30 Minutes

Also known as: GH 30

Clinical Use

Order Test

Use

For pediatric patients, very low peak growth hormone (GH) concentrations on stimulation testing are consistent with severe GH deficiency (GHD). Thresholds distinguishing normal from partial GHD have not been well established. Inadequate response to two different provocative tests is required for diagnosis of GHD. In adults, expected peak GH concentrations depend on the stimulation test performed, as described in Endocrine Society guidelines for the evaluation and treatment of adults with GHD. For suppression testing, healthy subjects have GH concentrations of less than 1 ng/mL within 2 hours of ingestion of a 75 or 100 gram glucose dose. Patients with acromegaly fail to show normal suppression.

Special Instructions

This Growth Hormone assay is 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.

Limitations

Thresholds distinguishing normal from partial GHD have not been well established. The test requires an inadequate response to two different provocative tests for diagnosis of GHD. Expected peak GH concentrations in adults depend on the stimulation test performed. Healthy subjects have GH concentrations of less than 1 ng/mL within 2 hours for suppression testing, while patients with acromegaly fail to show normal suppression.

Test Details

New York Approved

Methodology

Immunoassay (CLIA)

Biomarkers

Growth Hormone

Analyte

Growth Hormone • Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Order Codes

15347-8

Result Turnaround Time

1-2 days

Specimen

Plasma

Volume

1 mL per timed specimen

Minimum Volume

0.4 mL per timed specimen

Container

Plasma separator tube, serum separator tube, green (sodium or lithium heparin), lavender (EDTA), or pink (K2EDTA)

Collection Instructions

Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer to individual ARUP Standard Transport Tubes.