Effect of Ghrelin on Decision-Making
Study Details
Study Description
Brief Summary
This study evaluates the effect of the "hunger hormone" ghrelin on human decision-making. Participants will be given an injection of ghrelin or saline on different study days and will then be asked to make a series of computer-based decisions. The investigators hypothesize that ghrelin will increase participant's preference for energy-dense foods and will also increase impulsiveness in decision making.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
| Phase 1 |
Detailed Description
Ghrelin is a hormone made by the stomach that stimulates hunger and feeding behavior. How ghrelin affects human decision-making is poorly understood. This study will investigate the effect of ghrelin on nutrition-related and time-based decisions in humans. Participants eye movements will be tracked by a computer during the decision-making process.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Healthy Subjects - Ghrelin Healthy subjects will arrive after consuming a standard meal 60 minutes prior to study onset. They will receive a single subcutaneous injection of human synthetic Acyl Ghrelin at the start of the study. 5 minutes post-injection, the subjects will receive written instructions and begin their first decision-making task on a computer. |
Drug: Ghrelin
Subjects will receive a subcutaneous injection of synthetic acyl ghrelin (12 µg/kg) at the start of the study.
Other Names:
|
| Placebo Comparator: Healthy Subjects - Saline Healthy subjects will arrive after consuming a standard meal 60 minutes prior to study onset. They will receive a single subcutaneous injection of 0.9% saline at the start of the study. 5 minutes post-injection, the subjects will receive written instructions and begin their first decision-making task on a computer. |
Drug: Saline
Subjects will receive a subcutaneous injection of saline (0.9%) at the start of the study.
|
| Experimental: Obese Subjects - Ghrelin Obese subjects will arrive after consuming a standard meal 60 minutes prior to study onset. They will receive a single subcutaneous injection of human synthetic Acyl Ghrelin at the start of the study. 5 minutes post-injection, the subjects will receive written instructions and begin their first decision-making task on a computer. |
Drug: Ghrelin
Subjects will receive a subcutaneous injection of synthetic acyl ghrelin (12 µg/kg) at the start of the study.
Other Names:
|
| Placebo Comparator: Obese Subjects - Saline Obese subjects will arrive after consuming a standard meal 60 minutes prior to study onset. They will receive a single subcutaneous injection of 0.9% saline at the start of the study. 5 minutes post-injection, the subjects will receive written instructions and begin their first decision-making task on a computer. |
Drug: Saline
Subjects will receive a subcutaneous injection of saline (0.9%) at the start of the study.
|
Outcome Measures
Primary Outcome Measures
- Effect of Ghrelin on food choices in Task 1. [Approximately 25 minutes]
The difference in the proportion of healthy and unhealthy choices in the Saline and Ghrelin conditions.
- Effect of Ghrelin on temporal choices in Task 2 [Approximately 25 minutes]
The difference in the proportion of smaller sooner and larger later choices in the Saline and Ghrelin conditions
Secondary Outcome Measures
- Dwell time on each choice during Task 1 [Approximately 25 minutes]
For eye-tracking, total dwell time (in ms) on each item in a food choice will be compared in both experimental conditions.
- Number of fixations on foods during Task 1 [Approximately 25 minutes]
The total number of fixations on each food option will be compared in both experimental conditions.
- Dwell time on each choice during Task 2 [Approximately 25 minutes]
For eye-tracking, total dwell time (in ms) on each item in the monetary choice will be compared in both experimental conditions.
- Number of fixations on foods during Task 2 [Approximately 25 minutes]
The total number of fixations on each monetary option will be compared in both experimental conditions.
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Ability to speak and understand English
-
BMI of 18.0 - 24.9 kg/m2 or 30.0 - 50.0 kg/m2
Exclusion Criteria:
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Diagnosis of diabetes mellitus (including gestational diabetes)
-
Active infections
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History of malignant or inflammatory conditions, such as rheumatoid arthritis and inflammatory bowel disease
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History of myocardial infarction or congestive heart failure
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Active liver or kidney disease
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Uncontrolled hypertension
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Pituitary or adrenal disorders or neuroendocrine tumors
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History of anorexia nervosa, bulimia, or eating disorders not otherwise specified (NOS); Score of "at risk" on the EAT-26 eating disorder screening tool
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Diagnosis of attention-deficient/hyperactivity disorder (ADHD)
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Malabsorptive gastrointestinal disease, gastroparesis, or history of gastrointestinal surgery
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Pregnancy or lactation
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Requirement of daily medications that alter gastrointestinal function (including, but not limited to, glucocorticoids, psychotropics, narcotics, and metoclopramide).
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Requirement of glasses for impaired vision (including reading glasses). Subjects who wear contact lenses for vision correction will not be excluded.
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Insufficient visual acuity to read and interpret the decision stimuli
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Insufficient motor capabilities to press a button, move the joystick, or move their eyes to indicate a response
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Duke Sociology-Psychology Building 417 Chapel Drive | Durham | North Carolina | United States | 27708 |
Sponsors and Collaborators
- Jenny Tong, MD, MPH
Investigators
- Principal Investigator: Jenny Tong, MD, MPH, Duke Molecular Physiology Institute
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- Pro00077515