Influence of Intragastric Fatty Acid Infusion on Behavioral Responses to Positive Emotion Induction in Healthy Subjects

Study Overview
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Brief Summary
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The purpose of this study is to test whether intragastrically infused fatty acid will interact with positive emotion induction and if this effect is mediated by gut hormones.

Detailed Description
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This study aims at the possible effect of subliminal intragastric administration of fatty acids on responses to positive emotion induction, based on our earlier findings that subjective administration of fatty acid decreases neural responses to negative mood induction (Van Oudenhove et al, J Clin Invest 2011). After screening for exclusion criteria and the participants sign the informed consent form, an intravenous catheter is placed in the forearm, and a naso-gastric tube inserted through the nose. Then the test subject is connected to the equipment in order to record the activity of the autonomic nervous system, via three electrocardiogram electrodes. By using the nasogastric tube we serve a fatty acid solution (Dodecanoic acid, fatty acid condition) or a physiological saline solution ( control condition) intragastrically. The intragastric administration of low doses of this food ingredient has already been used in several previous studies by our research group and has proven perfectly safe. A positive or neutral emotional state will be induced by the combination of looking at emotional facial expressions and listening to classical music pieces that were previously validated for this purpose; This combination of incentives has already been used in previous studies of our research group. Responses will be measured by means of validated self-report scales and measurements of the vagal tone. We also take blood samples on a regular basis by the intravenous catheter for determination of gastrointestinal hormones, given our hypothesis that this may explain the effect on emotions. After removal of the nasogastric tube, the influence of subliminal administration of fatty acids and emotional state on food intake measured by means of a validated and previously drink test used in which participants ad libitum to drink a chocolate milkshake while the emotion-induction by means of classical music pieces continue. Finally, the intravenous catheter is removed.

Official Title
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Influence of Intragastric Fatty Acid Infusion on Behavioral Responses to Positive Emotion Induction in Normal Weight Subjects

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Dietary Supplement: Dodecanoic acid
* Behavioral: Positive emotion
* Dietary Supplement: saline
* Behavioral: neutral emotion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy women age > 18 and < 60. Body Mass Index (BMI) of 19-25 kg/m2 (no weight change of more than 5% of body weight in the past three months). Exclusion Criteria: chronic medical illness affecting the gastrointestinal, endocrine, cardiovascular or nervous system (risk of) pregnancy history of upper gastrointestinal surgery history of behavioral, therapeutic or surgical treatment aiming at or leading to weight loss/gain psychiatric disorders, including (history of) depression or eating disorders alcohol abuse or dependence regular use of medication, except for oral contraception use of any drugs, including cannabis, during the past 6 months

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

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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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: positive emotion and fatty acid<br>positive emotion induction combine with 2.g Dodecanoic acid intragastric infusion | Dietary Supplement: Dodecanoic acid<br>* The middle chain saturated fatty acid that can be widely found in daily food.<br>* Other names: Lauric acid;Behavioral: Positive emotion<br>* Positive emotion induced by facial expressions and classic music.<br>|
| Experimental: neutral emotion and fatty acid<br>neutral emotion induction combine with 2.g Dodecanoic acid intragastric infusion | Dietary Supplement: Dodecanoic acid<br>* The middle chain saturated fatty acid that can be widely found in daily food.<br>* Other names: Lauric acid;Behavioral: neutral emotion<br>* Neutral emotion induced by facial expressions and classic music.<br>|
| Experimental: positive emotion and saline<br>positive emotion induction combine with saline intragastric infusion | Behavioral: Positive emotion<br>* Positive emotion induced by facial expressions and classic music.<br>Dietary Supplement: saline<br>* saline<br>|
| Placebo Comparator: neutral emotion and saline<br>neutral emotion induction combine with saline intragastric infusion | Dietary Supplement: saline<br>* saline<br>Behavioral: neutral emotion<br>* Neutral emotion induced by facial expressions and classic music.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time evolution of VAS from the beginning until the end of a study visit | visual analogue scale for appetite related sensations | -10min 0min 10min 20min 30min 40min | 
| time evolution of gut hormones from the beginning until the end of a study visit |  | -10min 10min 20min 30min 40min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| evolution of heart rate variability |  | -20min 20min | 
| hedonic food intake | amount of milkshake drunk | 40min |