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Test ID HGH Growth Hormone, Serum

Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.6 mL

Collection Instructions:

1. Fasting

2. If multiple specimens are drawn, submit each vial under a separate order.

3. Label specimens appropriately (corresponding draw time).

Useful For

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)

Method Name

Immunoenzymatic Assay

Reporting Name

Growth Hormone, S

Specimen Type


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  90 days

Reject Due To


Mild OK; Gross reject


Mild OK; Gross OK





Clinical Information

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


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.


For SI unit Reference Values, see


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.


The test has limited value in assessing growth hormone secretion in normal children. IGF1I / 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; IGF1 / 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

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

Day(s) and Time(s) Performed

Monday through Friday 5 a.m. – 12 a.m., Saturday 6 a.m. – 6 p.m.

Analytic Time

1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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


LOINC Code Information

Test ID Test Order Name Order LOINC Value
HGH Growth Hormone, S 2963-7


Result ID Test Result Name Result LOINC Value
HGH Growth Hormone, S 2963-7

NY State Approved