Oral Glucose Tolerance Testing (OGTT) on Patients Taking Somatostatin Analogs

Study Overview
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Brief Summary
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The purpose of this study is to test the effect of long-acting somatostatin analog medications, taken by patients with acromegaly or carcinoid syndrome, on growth hormone in comparison to healthy controls who are not receiving the medication in order to see whether or not the medication makes the oral glucose test less accurate. The Oral Glucose Tolerance Test (OGTT) is a standard test to measure growth hormone secretion. By comparing GH responses in non-acromegaly subjects taking somatostatin analog treatment, the relative contribution of the medication and the underlying disease state can be analyzed.

Detailed Description
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Subjects will be informed of the study and after providing written informed consent, subjects will be asked to undergo a 2-hour oral glucose tolerance test (ingestion of 75g glucose with subsequent timed assessment of growth hormone, glucose, insulin and related binding proteins.) Baseline assessment of hormones that may contribute to the results will be drawn, prior to performing the test. Patients will be asked to complete one visit total to participate in this trial.

Official Title
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Hormonal and Metabolic Responses to Oral Glucose During Somatostatin Analog Use

Conditions
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Acromegaly

Intervention / Treatment
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* Other: Oral Glucose Tolerance Test (OGTT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of acromegaly or carcinoid syndrome Treatment with somatostatin analog therapy (must have established a stable dose of three or more injections on the same dose prior to study enrollment) Healthy control subjects Exclusion Criteria: Diagnosis of Diabetes Mellitus (Type 1 or Type 2) Use of medication for the treatment of insulin resistance or diabetes

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acromegaly<br>Patients carrying the diagnosis of acromegaly who are on long-acting somatostatin for at least 3 months prior to study enrollment. | Other: Oral Glucose Tolerance Test (OGTT)<br>* An OGTT is a test that lowers growth hormone in the body to very low levels for a short time in order to see how low the growth hormone levels are in your blood.<br>|
| Carcinoid Syndrome<br>Patients carrying a diagnosis of carcinoid syndrome who are taking long-acting somatostatin for at least 3 months prior to study enrollment. | Other: Oral Glucose Tolerance Test (OGTT)<br>* An OGTT is a test that lowers growth hormone in the body to very low levels for a short time in order to see how low the growth hormone levels are in your blood.<br>|
| Healthy Controls<br> | Other: Oral Glucose Tolerance Test (OGTT)<br>* An OGTT is a test that lowers growth hormone in the body to very low levels for a short time in order to see how low the growth hormone levels are in your blood.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Growth hormone response to OGTT | assessment of the validity of GH suppression during somatostatin analog treatment in acromegaly and non-acromegaly subjects | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Acromegaly, Growth Hormone, Carcinoid Syndrome, Somatostatin