Pegvisomant With Glucagon Test to Assess for Adult Growth Hormone Deficiency
Status:
Unknown status
Trial end date:
2013-12-01
Target enrollment:
Participant gender:
Summary
Hypothesis:
Pegvisomant combined with the glucagon stimulation test (GST) can improve the accuracy of
this test when used to diagnose adult GH and cortisol (steroid hormone)insufficiency.
Study aims:
Diagnosing GH and cortisol deficiency in adults requires a special test. At present, the
insulin tolerance test (ITT) is considered the test of choice. However, this test is
difficult to perform as it involves giving insulin through the veins to decrease blood sugars
to very low levels, and this can be unpleasant, and cannot be performed in elderly adults and
in those with a history of heart disease, seizure disorders or stroke. For this reason there
is an urgent need for an alternative reliable test. At present, the GST is considered the
alternative test to the ITT but its accuracy in obese patients and in those with diabetes
remains unclear. Pegvisomant is a medication that can increase GH production in the body. The
purpose of this study is to find out if combining pegvisomant with the GST can help improve
the accuracy of this test so that it is comparable with the ITT in diagnosing adult GH and
cortisol insufficiency.
Study design:
Subjects will be recruited from the Oregon Health & Science University Dynamic Endocrine
Testing Unit. A written informed consent will be obtained and a screening interview will be
carried out. During the screening interview, the study will be explained to the subject in
detail. For women of child-bearing age, a pregnancy test will be performed. The subjects will
then take part in three studies on separate days: (1) GST; (2) pegvisomant (1 mg/kg)
injection into the abdomen 3 days before the glucagon stimulation test (ii) insulin tolerance
test. For the GST, glucagon will be injected into the muscle and blood draws will be
performed every 30 mins for 240 mins. For the insulin tolerance test, a blood draw will be
performed and insulin will be given into the vein followed by blood draws every 15 mins for
120 mins. The data from all three studies will be analyzed in the study where the peak growth
hormone and cortisol levels for all three tests will be compared. A questionnaire will be
used at the end of the study for the subjects to rank the level of preference of the three
tests. The data of the study will be analyzed using a computer statistical program where the
identity of the subjects will be coded to maintain confidentiality.