Investigation of the Effects of Obesity Surgery on Appetitive Behaviour
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.
|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|
- 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.
- 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.
|Study Start Date:||February 2013|
|Estimated Study Completion Date:||February 2014|
|Estimated Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
Active Comparator: Octreotide
One subcutaneous injection - 1 mL
Other Name: Octreotide 100 micrograms/1ml - solution for injection - Hospira - Q64021
Placebo Comparator: Saline
One subcutaneous injection - 1 mL
Other Name: Sodium chloride 0.9% W/V injection BP - Fannin - PL 24598/0002
|Contact: Sophie Meillon, PhD||+353(0)email@example.com|
|Contact: Carel le Roux, Pr, MD||+353(0)firstname.lastname@example.org|
|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|
|Principal Investigator:||Carel le Roux, Pr, MD||UCD Conway institute|