Investigation of the Effects of Obesity Surgery on Appetitive Behaviour

Not Applicable

Completed

• Conditions: Roux-en-Y Bariatric Surgery
• Interventions: Drug: Saline; Drug: Octreotide

• Registration Number: NCT02010385
• Lead Sponsor: University College Dublin

Brief Summary

Among all the existing ways to treat obesity (lifestyle, pharmacological), Roux-en-Y gastric bypass (RYGB) surgery is currently the most effective. It results in long term weight loss maintenance, significant remission of obesity-related comorbidities and decreased overall mortality. It also induces changes in gastrointestinal hormones responses, with an increase of anorexigenic hormones GLP-1, and PYY.

Although successful, the mechanisms for RYGB-induced weight loss are not completely understood. The RYGB does result in increased satiation, decreased calorie intake and decreased preferences for sweet and fatty foods. Previous work from our lab has shown using progressive ratio task (PRT) that RYGB specifically decreases the appetitive behaviour for sweet and fat stimuli but not for vegetables. The reasons for this change in appetitive behaviour after the surgery remain unknown. They may be triggered by changes in gut hormones, conditioned taste aversion (negative post-ingestive effects) or changes in serum bile acids levels.

This study aims to assess whether RGYB-induced gut hormone changes contribute to the decrease in appetitive behaviour for sweet and fatty foods observed after the surgery.

This is a double blind controlled study comparing the effect of blocking gut hormones with somatostatin analogue (octreotide) on the appetitive behaviour for sweet-fat candies will be carried out. Appetitive behaviour will be measured using the progressive ratio task.

The investigators hypothesize that blocking the gut hormones in obese patients with RYGB will increase their appetitive behaviour for sweet-fat candies.

Detailed Description

Not available

Study Timeline

• Study Start: 2013-02
• Study First Submitted: 2013-12-09
• Study First Submitted QC: 2013-12-11
• Study First Posted: 2013-12-12
• Primary Completion: 2018-06
• Study Completion: 2018-06
• Status Verified: 2022-05
• Last Update Submitted: 2022-05-20
• Last Update Posted: 2022-05-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Gastric bypass surgery since at least 6 months

Exclusion Criteria

• serious illness
• pregnancy or breast feeding
• more than three alcoholic drinks per day
• substance abuse
• psychiatric illness
• significant longstanding heart disease or heart intervention (for example, patients who have had heart attacks, have pacemakers or have had heart surgery)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Saline	Saline	One subcutaneous injection - 1 mL
Octreotide	Octreotide	One subcutaneous injection - 1 mL

Primary Outcome Measures

Name	Time	Method
Progressive ratio breakpoint	One hour	In the Progressive ratio task, the participants click a computer mouse in order to obtain a sweet/fat food reward. The effort required to obtain a reward is progressively increased. The breakpoint refers to the point at which the reward value of the food stimulus is lower than the effort necessary to obtain it and the participant stops pressing the button.

Secondary Outcome Measures

Name	Time	Method
Subjective ratings	One hour	Hunger, fullness, desire in eating and nausea state will be assessed using Visual Analogue Scales (VAS).
Gut hormones level	One hour	GLP-1, ghrelin, leptin and insulin levels will be measured.

Trial Locations

Locations (1)

University College Dublin Clinical Research Centre; 🇮🇪 Dublin, Ireland