Normal levels of growth hormone (GH) change
during the day so other tests may be done to confirm the results of a GH test.
Other tests can show whether low levels of GH (which can be normal) mean the
pituitary gland is not working correctly.
The growth hormone suppression test (also called the
glucose loading test) measures the level of GH in the blood before and after a
person drinks fluid with a large amount of sugar (glucose) in it. Normally, the
amount of GH drops to less than 1 ng/mL after drinking the glucose. Levels of
GH that stay high may mean acromegaly is present.
hormone stimulation test measures the level of GH in the blood before and after
insulin or arginine is given in a vein (intravenously)
in the arm. No detectable growth hormone can be found for people with normal pituitary function. A growth hormone
stimulation test may be used to see if a person lacks GH. Normally, the amount
of GH increases after insulin or arginine. A GH level that does not increase
after the insulin or arginine is given may mean the person lacks growth
Other Works Consulted
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.