Modulating the GIP System in Patients With Acromegaly Due to a Pituitary Tumor

Study Overview
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Brief Summary
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Modulation of the GIP System in Patients With Acromegaly Due to a Pituitary adenoma

Detailed Description
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Aim: To determine the importance of the GIP system in patients with acromegaly who has paradoxical growth hormone secretion during an oral glucose tolerance test (OGTT) using a GIP antagonist (GIP-A). Thirty participants (age 18-75 years) with normal kidney and liver parameters and hemoglobin levels will be included in a placebo-controlled cross-over study. The study consists of two study days with concomitant infusions of A) GIP-A or B) saline (placebo). A paradoxical growth hormone secretion to an OGTT is here defined as an increase in plasma growth hormone levels of ≥30% from baseline based on a mean value of the definitions in the literature. Regazzo et al. (2017) European Journal of Endocrinology 176, 543-553 Mukai et al. (2018) The Journal of Clinical Endocrinology and Metabolism 104(5), 1637-1644 Hage et al. (2019) The Journal of Clinical Endocrinology and Metabolism 104(5), 1777-1787 Scaroni et al. (2019) J Clin Endocrinol Metab 104(3), 856-862

Official Title
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Modulating the Glucose-dependent Insulinotropic Polypeptide (GIP) System in Patients With Acromegaly Due to a Pituitary Tumor

Conditions
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Acromegaly Due to Pituitary Adenoma

Intervention / Treatment
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* Other: GIP-A
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients under clinical investigation of acromegaly disease with normal kidney function, liver function and hemoglobin levels. Exclusion Criteria: Medication for acromegaly, adenectomy, liver disease, uncontrolled anemia, severe heart disease, uncontrolled high blood pressure (>170/100 mmHg), current pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: GIP-A<br>Infusion of GIP-A alone as a study tool. | Other: GIP-A<br>* GIP-A<br>|
| Placebo Comparator: Placebo<br>Saline | Other: Placebo<br>* Placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Growth hormone levels | Plasma growth hormone area under the curve (AUC) | 240 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glucose levels | Plasma glucose AUC | 240 min | 
| GIP levels | Plasma GIP AUC | 240 min | 
| Insulin levels | Serum insulin AUC | 240 min | 
| C-peptide levels | Serum C-peptide AUC | 240 min | 
| Insulin-like growth factor-1 (IGF-1) levels | Plasma IGF-1 AUC | 240 min | 
| Free fatty acids (FFA) levels | serum FFA AUC | 240 min | 
| Glucagon levels | plasma glucagon AUC | 240 min | 
| Ghrelin levels | plasma ghrelin AUC | 240 min | 
| GLP-1 levels | Plasma GLP-1 AUC | 240 min | 
| GLP-2 levels | Plasma GLP-2 AUC | 240 min | 
| Plasma cholesterol | Plasma cholesterol AUC | 240 min | 
| Plasma triglyceride | Plasma triglyceride AUC | 240 min | 
| Plasma TSH | Plasma TSH AUC | 240 min | 
| Plasma prolactin | Plasma prolactin AUC | 240 min |