Growth Hormone, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Diagnosis of acromegaly and assessment of treatment efficacy (in conjunction with glucose suppression test)
Diagnosis of human growth hormone deficiency (in conjunction with growth hormone stimulation test)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Growth Hormone, S
Growth Hormone Provocative Test
Growth Hormone Stimulation
hGH (Human Growth Hormone)
Human Growth Hormone
Growth Hormone Stimulation
hGH (Human Growth Hormone)
Human Growth Hormone
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.6 mL
2. If multiple specimens are drawn, submit each vial under a separate order.
3. Label specimens appropriately (corresponding draw time).
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Refrigerated (preferred)||7 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The anterior pituitary secretes human growth hormone (hGH) in response to exercise, deep sleep, hypoglycemia, and protein ingestion. hGH stimulates hepatic insulin-like growth factor-1 and mobilizes fatty acids from fat deposits to the liver. Hyposecretion of hGH causes dwarfism in children. Hypersecretion causes gigantism in children or acromegaly in adults.
Because hGH levels in normal and diseased populations overlap, hGH suppression and stimulation tests are needed to evaluate conditions of hGH excess and deficiency; random hGH levels are inadequate.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Males: 0.01-0.97 ng/mL
Females: 0.01-3.61 ng/mL
Reference intervals have not been formally verified in-house for pediatric and adolescent patients. The published literature indicates that reference intervals for adult, pediatric, and adolescent patients are comparable.
Acromegaly: For suppression testing, normal subjects have a nadir growth hormone (GH) concentration of <0.3 ng/mL after ingestion of a 75-gram glucose dose. Patients with acromegaly fail to show normal suppression. Using the Access ultrasensitive hGH assay, a cutoff of 0.53 ng/mL for nadir GH was found to most accurately differentiate patients with acromegaly in remission from active disease with a sensitivity of 97% (95% CI, 83%-100%) and a specificity of 100% (95% CI, 82%-100%).(1)
Deficiency: A normal response following stimulation tests is a peak GH concentration >5 ng/mL in children and >4 ng/mL in adults. For children, some experts consider GH values between 5 ng/mL and 8 ng/mL equivocal and only GH peak values >8 ng/mL as truly normal. Low levels, particularly under stimulation, indicate human growth hormone deficiency.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The test has limited value in assessing growth hormone secretion in normal children. IGF1I/35099 Insulin-Like Growth Factor 1, Serum is recommended as the first test for assessing deficient or excess growth during childhood and adolescent development; reference intervals for Tanner stages are available. Suspected causes of dwarfism need to be diagnosed with the aid of provocative testing.
This test is not useful as a screen for acromegaly; IGF1I/35099 Insulin-Like Growth Factor 1, Serum is preferred. Elevated levels of human growth hormone indicate the possibility of gigantism or acromegaly, but must be confirmed with stimulation and suppression testing.
Growth hormone is secreted in surges; single measurements are of limited diagnostic value.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Bancos I, Algeciras-Schimnich A, Woodmansee WW, et al: Determination of nadir growth hormone concentration cutoff following oral glucose tolerance testing using the Beckman Coulter ultrasensitive growth hormone assay patients with newly diagnosed acromegaly, acromegaly in remission, and healthy subjects. Endocr Pract 2013 Jun 27:1-26 (Epub ahead of print)
2. Camacho-Hubner C: Assessment of growth hormone status in acromegaly: what biochemical markers to measure and how? Growth Hormone IGF Res 2000;10 Suppl B:S125-299
3. Nilsson AG: Effects of growth hormone replacement therapy on bone markers and bone mineral density in growth hormone-deficient adults. Horm Res 2000;54 Suppl 1:52-57
4. Strasburger CJ, Dattani MT: New growth hormone assays: potential benefits. Acta Paediatr 1997 Nov;Suppl 423:5-11
5. Okada S, Kopchick JJ: Biological effects of growth hormone and its antagonist. Trends Mol Med 2001Mar;7:126-132
6. Veldhuis JD, Iranmanesh A: Physiological regulation of human growth hormone (GH)-insulin-like growth factor type I (IGF-I) axis: predominant impact of age, obesity, gonadal function, and sleep. Sleep 1996;19:S221-224
Method Description Describes how the test is performed and provides a method-specific reference
The instrument used is the Beckman Coulter UniCel DXI 800. The Access Ultrasensitive human growth hormone (hGH) assay is a simultaneous one-step immunoenzymatic ("sandwich") assay. A sample is added to a reaction vessel along with polyclonal goat anti-hGH alkaline phosphatase conjugate and paramagnetic particles coated with mouse monoclonal anti-hGH antibody. The patient sample hGH binds to the monoclonal anti-hGH on the solid phase, while the goat anti-hGH-alkaline phosphatase conjugate reacts with a different antigenic site on patient sample hGH. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of hGH in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve. (Beckman Coulter Assay Manual 2007. Beckman Coulter Inc. 4300 N Harbor Blvd. Fullerton, CA 92835)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday 5 a.m. – 12 a.m., Saturday 6 a.m. – 6 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|HGH||Growth Hormone, S||2963-7|