Pegvisomant With Glucagon Test to Assess for Adult Growth Hormone Deficiency

Status

Status unknown

Phase

Not applicable

Enrollment

10 participants (estimated)

Sponsor

Oregon Health and Science University · Other

Design

Randomized · Open label (no masking)

Countries

1 country

United States

Start

Mar 2011

Primary completion

Nov 2013 (estimated)

Completion

Dec 2013 (estimated)

First posted

5 Mar 2013 (estimated)

Last update posted

24 Oct 2013 (estimated)

Conditions

Adults Growth Hormone Deficiency.

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.

• Active comparator

  Pegvisomant-glucagon test

  To compare the combined pegvisomant with the glucagon test to the insulin tolerance test and the glucagon test in diagnosing adult growth hormone and cortisol insufficiency.

• Active comparator

  Insulin tolerance test

  To compare the combined pegvisomant with the glucagon test to the insulin tolerance test and the glucagon test in diagnosing adult growth hormone and cortisol insufficiency.

1. Peak growth hormone and cortisol levels induced by the pegvisomant-glucagon test compared to those by the insulin tolerance test in assessing the growth hormone and cortisol reserve in adults suspected of adult growth hormone and cortisol deficiencies.

   Time frame · 9 weeks

   Registry description

   Presently, the insulin tolerance test (ITT) is regarded as the gold standard test in diagnosing adult GH deficiency but this test is difficult to perform in patients with diabetes mellitus, and contraindicated in the elderly, and in adults with seizures and ischemic heart disease. Glucagon test is the alternative test to the ITT but its accuracy and reliability is questionable in obesity and diabetes mellitus. Pegvisomant is a GH receptor blocker that increases GH secretion. When primed with glucagon, pegvisomant may enhance GH secretion by providing a stronger stimulus than glucagon alone. We plan to assess if by priming pegvisomant with glucagon will improve the accuracy of this test in diagnosing adult GH cortisol deficiency. Specifically, we will examine the characteristics of peak GH and cortisol levels, and ascertain the peak GH and cortisol levels in comparison to those generated using the ITT in diagnosing GH and cortisol deficiency.