Growth Hormone Feedback to Insulin-like Growth Factor-I (IGF-1) and Oral Glucose Tolerance Test (OGTT)
Recruitment status was Recruiting
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Purpose
Growth hormone (GH) and Insulin-like growth factor-I (IGF-I) secretion are altered in acromegaly and type 2 Diabetes Mellitis (DM). The secretion of GH is mediated by central hypothalamic hormones (GH Releasing Hormone and somatostatin) as well as peripheral factors providing feedback inhibition (IGF-I and glucose, among others). The purpose of this study is to compare growth hormone suppression after an oral glucose tolerance test (OGTT) to growth hormone suppression after recombinant human IGF-I (rhIGF-I) administration. This study will recruit participants with active acromegaly, type 2 diabetes mellitus, and healthy control subjects. Each participant will undergo a screening evaluation, and three subsequent visits. Each participant will receive a placebo subcutaneous injection, OGTT, and administration of rhIGF-I, on separate visit days. Glucose, insulin, GH, bioactive IGF-I and IGF-I binding proteins will be measured after each intervention. Results will be compared between the three groups. It is predicted that the administration of rhIGF-I will demonstrate GH suppression in all healthy subjects and subjects with type 2DM. Some acromegaly subjects may demonstrate GH suppression in response to IGF-I administration, but not to the degree seen in healthy subjects or type 2 DM. OGTT will demonstrate suppression of GH in normal subjects, and will show attenuated suppression in type 2 DM and a failure of suppression in acromegaly.
| Condition | Intervention | Phase |
|---|---|---|
|
Acromegaly Type 2 Diabetes Mellitus |
Other: oral glucose tolerance test Other: Subcutaneous administration of recombinant human IGF-1 |
Phase 4 |
| Study Type: | Interventional |
| Study Design: | Masking: Single Blind (Subject) |
| Official Title: | Growth Hormone Feedback In Patients With Acromegaly, Type 2 Diabetes Mellitus, And Healthy Adults |
- Growth hormone nadir, defined as the lowest measured growth hormone after administration of a suppressive agent (oral glucose or rhIGF-I) [ Designated as safety issue: No ]
- Changes in IGFBP-1, insulin, glucose, bioactive IGF-I after administration of placebo, OGTT and rhIGF-I [ Designated as safety issue: No ]
| Estimated Enrollment: | 30 |
| Study Start Date: | December 2008 |
-
Other: oral glucose tolerance test
Eligibility| Ages Eligible for Study: | 18 Years and older |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Active acromegaly due to excess GH produced by a pituitary adenoma.
- Patients must have an elevated IGF-I compared to age and gender matched controls (as supplied by the laboratory) and fail to suppress GH to below 1 ng/ml after a standard 75g oral glucose tolerance test.
- Type 2 diabetes mellitus, defined by elevated fasting glucose ≥ 126 mg/dl (verified by two historical measurements), or plasma glucose ≥ 200 mg/dl two hours after a 75 g oral glucose load, or a random glucose ≥ 200 mg/dl.
Exclusion Criteria:
Acromegaly Group
- Current medical therapy for acromegaly including dopamine agonists, somatostatin analogues, or growth hormone antagonists.
For subjects on current therapy the following washout periods may be used:
- Cabergoline: 4 weeks
- Bromocriptine: 1 week
- Sandostatin LAR: 3 months
- Short-acting octreotide: 1 week
- Lanreotide: 3 months
- Pegvisomant: 4 weeks
- Subjects with a history of surgical therapy for treatment of acromegaly must have verification of active disease with verified elevated IGF-I for the subjects' age and gender compared to healthy controls (as supplied by the laboratory) (two measures) as well as a failure to suppress GH to below 1 ng/ml after OGTT.
- Current treatment for insulin resistance or type 2 DM including oral or injection medications.
- Fasting glucose ≥ 126 mg/dl at screening evaluation.
- Evidence of hepatic or renal disease defined as elevated transaminases, elevated serum creatinine.
- Pregnancy or breast feeding.
Type 2 diabetes mellitus group
- Patients taking non-insulin medications for diabetes treatment will be excluded.
- Diagnosis of acromegaly.
- Evidence of hepatic or renal disease defined as elevated transaminases, elevated serum creatinine.
- Pregnancy or breast feeding.
Healthy Control Group
- History of diabetes mellitus or impaired glucose tolerance, history of acromegaly.
- Fasting glucose ≥ 126 mg/dl at screening evaluation.
- Evidence of hepatic or renal disease defined as elevated transaminases, elevated serum creatinine.
- Pregnancy or breast feeding.
Contacts and Locations| Contact: William Gellepis | 310-423-3395 | William.Gellepis@cshs.org |
| Contact: Lori Korsakoff, RN | 310-423-2411 | korsakoffl@cshs.org |
| United States, California | |
| Cedars-Sinai Medical Center Pituitary Center | Recruiting |
| Los Angeles, California, United States, 90048 | |
| Principal Investigator: John Carmichael, MD | |
More Information
No publications provided
| ClinicalTrials.gov Identifier: | NCT00915954 History of Changes |
| Other Study ID Numbers: | 17015 |
| Study First Received: | June 5, 2009 |
| Last Updated: | July 28, 2009 |
| Health Authority: | United States: Institutional Review Board |
Keywords provided by Cedars-Sinai Medical Center:
|
Acromegaly Type 2 diabetes mellitus recombinant human IGF1 oral glucose tolerance test |
Additional relevant MeSH terms:
|
Acromegaly Diabetes Mellitus Diabetes Mellitus, Type 2 Bone Diseases, Endocrine Bone Diseases Musculoskeletal Diseases Hyperpituitarism Pituitary Diseases |
Hypothalamic Diseases Brain Diseases Central Nervous System Diseases Nervous System Diseases Endocrine System Diseases Glucose Metabolism Disorders Metabolic Diseases |
ClinicalTrials.gov processed this record on June 17, 2013