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

Hormonal and Metabolic Responses to Oral Glucose During Somatostatin Analog Use

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.

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.

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