Growth hormone

Keywords: GH

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.

Consider IGF-1 to screen for acromegaly and gigantism.

See Growth hormone stimulation, Growth hormone suppression, and IGF-1.

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 acromegaly and gigantism.

Reference:

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