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Epic Test Code LAB525 Growth Hormone, Serum

Additional Codes

MML Code: HGH

 

NY State Approved

Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Growth Hormone, S

Method Name

Immunoenzymatic Assay

Specimen Stability Information

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


Ordering Guidance


For assessing growth hormone secretion in normal children, the recommended test is IGFMS / Insulin-Like Growth Factor 1, Mass Spectrometry, Serum.

 

For acromegaly screening, the preferred test is IGFGP / Insulin-Like Growth Factor 1 and Insulin-Like Growth Factor-Binding Protein 3 Growth Panel, Serum.



Specimen Required


Patient Preparation: For at least 8 hours, patient should be fasting.

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.6 mL

Collection Instructions:

1. If multiple specimens are collected, submit each vial under a separate order.

2. Label specimens appropriately with the corresponding collection times.


Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Reference Values

Males:

2-<7 years:* 0.05-5.11 ng/mL

7-<12 years:* 0.02-4.76 ng/mL

12-<14 years:* 0.01-6.20 ng/mL

14-<18 years:* 0.02-3.81 ng/mL

≥18 years: 0.01-0.97 ng/mL

 

Females:

2-<7 years:* 0.05-5.11 ng/mL

7-<12 years:* 0.02-4.76 ng/mL

12-<14 years:* 0.01-6.20 ng/mL

14-<18 years:* 0.03-5.22 ng/mL

≥18 years: 0.01-3.61 ng/mL

*Source: Karbasy K, Lin DC, Stoianov A, et al. Pediatric reference value distributions and covariate-stratified reference intervals for 29 endocrine and special chemistry biomarkers on the Beckman Coulter Immunoassay Systems: a CALIPER study of healthy community children. Clin Chem Lab Med. 2016;54(4):643-657. doi:10.1515/cclm-2015-0558

 

Reference intervals for patients younger than 2 years have not been established.

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Report Available

1 to 3 days

Day(s) Performed

Monday through Saturday

CPT Code Information

83003

Reject Due To

Gross hemolysis Reject
Gross lipemia OK

Useful For

Diagnosis of acromegaly and assessment of treatment efficacy when interpreted in conjunction with results from glucose suppression test

 

Diagnosis of human growth hormone deficiency when interpreted in conjunction with results from growth hormone stimulation test

 

This test is not intended for use as a screen for acromegaly.

 

This test has limited value in assessing growth hormone secretion in normal children.

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.

Interpretation

Acromegaly: For suppression testing, normal subjects have a nadir human growth hormone (hGH) concentration below 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 hGH was found to differentiate patients most accurately 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 hGH concentration above 5 ng/mL in children and above 4 ng/mL in adults. For children, some experts consider hGH values between 5 ng/mL and 8 ng/mL equivocal and only GH peak values greater than 8 ng/mL as truly normal. Low levels, particularly under stimulation, indicate hGH deficiency.

Cautions

As the human growth hormone (hGH) test has limited value in assessing growth hormone secretion in normal children, IGFMS / Insulin-Like Growth Factor 1, Mass Spectrometry, Serum is recommended as the first test for assessing deficient or excess growth during childhood and adolescent development. IGF1 reference intervals for Tanner stages are available. Suspected causes of dwarfism should be diagnosed with the aid of provocative testing.

 

Elevated levels of hGH 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.

Specimen Retention Time

14 days

Forms

If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.