PET-study on the Role of the Reward System in Weight Loss After Bariatric Surgery

NCT05359887 | Active Not Recruiting

• 1 other identifier: UMCG202100632
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Bariatric surgery (BS) is currently the most effective treatment in severe obesity. However, a considerable percentage of patients undergoing BS fail to lose sufficient weight or regain weight after initial weight loss during long-term follow-up, which may be attributed to personality traits and pathological eating behaviour. Previous positron emission tomography (PET) studies have shown reduced dopamine D2 receptor availability in obese patients and upregulation of this availability following successful BS in the brain's reward system. Dopamine D2 receptor availability in patients with unsuccessful BS has not been investigated to date.

Conditions

Obesity

Keywords

Obesity; Reward system; PET-scan; [11C]-Raclopride

Outcome Measures

Primary Outcomes (1)

• Change in [11C]-raclopride binding potential in the brain's reward system between study groups before and after a food challenge.

  Pre- and post-eating changes in dopamine D2 receptor availability as indexed by the \[11C\]-raclopride binding potential in the brain's reward system between subjects who underwent successful vs unsuccessful bariatric surgery

  -50 minutes (before start of PET scanning), 0 minutes (during PET break, before mixed meal), 30 minutes (after second phase of PET-scanning)

Secondary Outcomes (2)

• The correlation between [11C]-raclopride binding potential in the brain's reward system and of questionnaires and diaries

  Pre-intervention

• The correlation between [11C]-raclopride binding potential in the brain's reward system and of gut hormones.

  -50 minutes (before start of PET scanning), 0 minutes (during PET break, before mixed meal), 30 minutes (after second phase of PET-scanning), 60 - 90 - 120 minutes

Study Arms (2)

Unsuccessful BS (Total Weight Loss (TWL) < 20%)

EXPERIMENTAL

Fifteen who had unsuccessful BS (Total Weight Loss (TWL) \< 20%)

Other: standardized liquid mixed meal Nutridrink®

Successful BS (TWL > 25%).

EXPERIMENTAL

Fifteen who had successful BS (TWL \> 25%).

Other: standardized liquid mixed meal Nutridrink®

Interventions

standardized liquid mixed meal Nutridrink® OTHER

Administration of food in controlled situation

Successful BS (TWL > 25%).; Unsuccessful BS (Total Weight Loss (TWL) < 20%)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Bariatric surgery 24-36 months prior to the study
• Adult (over 18y old)
• Mentally capable to understand the consequences of the procedure and make his or her own choice without coercion
• Able to undergo PET and MRI, according to the investigator's assessment
• Native speaking
• Able to participate in follow-up
• Written informed consent

You may not qualify if:

• Presence of a DSM-IV axis 1 disorder
• The use of drugs that bind to dopamine D2/3 receptors, including various classes of antipsychotics and antidepressants
• History of stroke, brain tumor, Parkinson's Disease or dementia
• History of head trauma with loss of consciousness
• Alcohol or substance abuse in the last 6 months
• Alcohol consumption 24h prior to PET scanning
• Smoking or other forms of nicotine intake 12 hours prior to PET scanning
• Use of anorectic drugs in the last 6 months
• Current pregnancy
• Medication for Diabetes Mellitus
• Claustrophobia
• The presence of implanted metal objects of the type which may concentrate radiofrequency fields or cause tissue damage from twisting in a magnetic field (such as certain implanted devices, shrapnel, ocular metal shavings)
• Patients with a bodyweight \> 200kg will be excluded to ensure the maximum load of the camera bed of the PET-scanner (227 kg) is not exceeded.

Sponsors & Collaborators

• University Medical Center Groningen: lead

Study Sites (1)

MCL

Leeuwarden, Netherlands

Location

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 12, 2022
• First Posted: May 4, 2022
• Study Start: December 1, 2022
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 29, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

NL (1)