Investigation of the Effects of Obesity Surgery on Appetitive Behaviour

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2015 by University College Dublin
Information provided by (Responsible Party):
Carel le Roux, University College Dublin Identifier:
First received: December 9, 2013
Last updated: May 28, 2015
Last verified: May 2015

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 Intervention
Roux-en-Y Bariatric Surgery
Drug: Octreotide
Drug: Saline

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Health Services Research
Official Title: Investigation of the Effects of Obesity Surgery on Appetitive Behaviour - Impact of Gut Hormones

Resource links provided by NLM:

Further study details as provided by University College Dublin:

Primary Outcome Measures:
  • Progressive ratio breakpoint [ Time Frame: One hour ] [ Designated as safety issue: No ]
    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 [ Time Frame: One hour ] [ Designated as safety issue: No ]
    Hunger, fullness, desire in eating and nausea state will be assessed using Visual Analogue Scales (VAS).

  • Gut hormones level [ Time Frame: One hour ] [ Designated as safety issue: No ]
    GLP-1, ghrelin, leptin and insulin levels will be measured.

Estimated Enrollment: 30
Study Start Date: February 2013
Estimated Study Completion Date: February 2016
Estimated Primary Completion Date: February 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Octreotide
One subcutaneous injection - 1 mL
Drug: Octreotide
Other Name: Octreotide 100 micrograms/1ml - solution for injection - Hospira - Q64021
Placebo Comparator: Saline
One subcutaneous injection - 1 mL
Drug: Saline
Other Name: Sodium chloride 0.9% W/V injection BP - Fannin - PL 24598/0002


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
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)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02010385

Contact: Sophie Meillon, PhD +353(0)864506131
Contact: Carel le Roux, Pr, MD +353(0)864117842

University College Dublin Clinical Research Centre Recruiting
Dublin, Ireland, Dublin 4
Contact: Mat Arimin, MD    +353(0)851187100      
Principal Investigator: Carel le Roux, Pr, MD         
Sponsors and Collaborators
University College Dublin
Principal Investigator: Carel le Roux, Pr, MD UCD Conway institute
  More Information

Responsible Party: Carel le Roux, Prof, PhD, MSc, MRCPath, MRCP, MBChB, University College Dublin Identifier: NCT02010385     History of Changes
Other Study ID Numbers: Le Roux 12 June 12
Study First Received: December 9, 2013
Last Updated: May 28, 2015
Health Authority: Ireland: Medical Ethics Research Committee

Keywords provided by University College Dublin:
Bariatric surgery
Food behaviour
Gut hormones

Additional relevant MeSH terms:
Antineoplastic Agents
Antineoplastic Agents, Hormonal
Gastrointestinal Agents
Pharmacologic Actions
Therapeutic Uses processed this record on November 27, 2015