Investigation of the Effects of Obesity Surgery on Appetitive Behaviour

Sponsor

University College Dublin (Other)

Overall Status

Completed

CT.gov ID

NCT02010385

Collaborator

(none)

Enrollment

Location

Arms

63.9

Duration (Months)

0.5

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Roux-en-Y Bariatric Surgery	Drug: Octreotide Drug: Saline	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

30 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Double (Participant, Investigator)

Primary Purpose:

Health Services Research

Official Title:

Investigation of the Effects of Obesity Surgery on Appetitive Behaviour - Impact of Gut Hormones

Study Start Date :

Feb 1, 2013

Actual Primary Completion Date :

Jun 1, 2018

Actual Study Completion Date :

Jun 1, 2018

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Octreotide One subcutaneous injection - 1 mL	Drug: Octreotide Other Names: Octreotide 100 micrograms/1ml - solution for injection - Hospira - Q64021
Placebo Comparator: Saline One subcutaneous injection - 1 mL	Drug: Saline Other Names: Sodium chloride 0.9% W/V injection BP - Fannin - PL 24598/0002

Arm

Intervention/Treatment

Active Comparator: Octreotide

One subcutaneous injection - 1 mL

Drug: Octreotide

Other Names:

Octreotide 100 micrograms/1ml - solution for injection - Hospira - Q64021

Placebo Comparator: Saline

One subcutaneous injection - 1 mL

Drug: Saline

Other Names:

Sodium chloride 0.9% W/V injection BP - Fannin - PL 24598/0002

Outcome Measures

Primary Outcome Measures

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

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.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 65 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

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)