Growth hormone - plasma or serum

Last updated: Sunday, 14, March, 2004
Item Process
Specimen

5 mL blood in lithium heparin or plain tube. The patient should be unstressed and fasting.

Method

Immunoassay.

Reference Interval

Dependent on age and assay method. Consult pathologist.

Application

Pituitary and hypothalamic disorders causing growth abnormalities.

Growth hormone as an isolated test is of limited value as levels fluctuate considerably in normal individuals. Dynamic tests are required for proper diagnosis.

See Growth hormone stimulation testGrowth hormone suppression testIGF-I.

Interpretation

Low levels which are not able to be stimulated to a level achieved by normal subjects occur in pituitary dwarfism in children.

High or normal levels which cannot be suppressed are found in gigantism and acromegaly.

IGF-1 is a better screening test for acromegally and gigantism.

Reference

Simard MF. Neurosurg Clin N Am 2003; 14(1): 41-54.