Growth hormone suppression test

Last updated: Monday, 22, March, 2004

MBS Online Search Page: Click here for details

Item Process
Specimen

2 mL blood in a lithium heparin or plain tube.

Method

Glucose - spectrophotometry. Growth hormone - immunoassay.

Protocol

Blood is taken prior to a 75 g glucose load and then every 30 minutes for 3 hours.

Reference Interval

Suppression to <4 mU/L (<2 µg/L) in at least one specimen.

Application

Definitive test for the diagnosis of acromegaly or pituitary gigantism.

IgF-I is used for initial assessment. See IGF-I.

Interpretation

Failure of growth hormone to suppress indicates autonomous growth hormone release by the anterior pituitary.

Reference

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