Obesity, patients with monogenic obesity, and patients undergoing upper GI surgery Nutritional, Metabolic, Endocrine Obesity, gastrectomy, monogenic obesity
Conditions
Interventions
This is an observational study that takes place over two days in the Cambridge Clinical Research Centre at Addenbrooke’s hospital. The study combines a series of cognitive, behavioural neuroimaging, h
Sponsors
University of Cambridge
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: All participants: 1. Aged 18-45 years 2. Written informed consent given 3. Estimated IQ =80 measured using the WASI-II Full Scale-2 4. Ambulatory 5. Normal or corrected-to-normal vision Gastrectomy patient group: 1. Aged 18-60 years 2. If post-operative, clinically stable Monogenic obesity patient group: 1. Identified mutation in MC4R, LepR, or SIM1 genes
Exclusion criteria
Exclusion criteria: All participants: 1. Not fluent English speaker 2. Current serious neurological or psychiatric illness, including neurodevelopmental disorders; schizophrenia spectrum and other psychotic disorders; bipolar and related disorders; substance-related and addictive disorders; obsessive-compulsive and related disorders; anorexia nervosa, bulimia nervosa, binge-eating disorder, or otherwise specified feeding or eating disorder; previous bariatric or gastric bypass (Roux-en-Y) surgery 3. Type 1 or Type 2 diabetes 4. Evidence of anaemia, metabolic or cardiovascular disease, or disease that may influence metabolism or blood measurements (such as cancer or thyroid disease) 5. Dietary restrictions that cannot be accommodated by the metabolic kitchen 6. Pregnancy or lactation 7. Contraindications to MRI scanning (such as pacemakers, metallic prostheses such as cochlear implants or heart valves, or shrapnel fragments) 8. Claustrophobic to a degree that they would feel uncomfortable in the MRI scanner Lean group: 1. Left-handedness 2. BMI outside of the range 18.5-24.9 kg/m² 3. Lifetime history of any of the following DSM-5 psychiatric conditions: 3.1. Obsessive-Compulsive and Related Disorders 3.2. Trauma- and Stressor-Related Disorders 3.3. Dissociative Disorders 3.4. Somatic Symptom and Related Disorders 3.5. Disruptive, Impulse-Control, and Conduct Disorders 4. Recent history (previous 6 months) of any of the following DSM-5 psychiatric conditions 4.1. Depressive Disorders 4.2. Anxiety Disorders 5. Current use of antidepressant or anxiolytic medication Diet-induced obesity group: 1. Left-handedness 2. BMI <29.9 kg/m² 3. Lifetime history of any of the following DSM-5 psychiatric conditions: 3.1. Obsessive-Compulsive and Related Disorders 3.2. Trauma- and Stressor-Related Disorders 3.3. Dissociative Disorders 3.4. Somatic Symptom and Related Disorders 3.5. Disruptive, Impulse-Control, and Conduct Disorders 4. Recent history (previous 6 months) of any of the following DSM-5 psychiatric conditions 4.1. Depressive Disorders 4.2. Anxiety Disorders 5. Current use of antidepressant or anxiolytic medication Gastrectomy and monogenic obesity patient groups: 1. Treating clinician has any concerns that participation in the study may have a deleterious effect on the participant’s health or ongoing treatment
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Cognitive measures of habitual and goal-directed learning and their relationships to interoceptive measures of arousal and brain imaging measured using the following measures on the mornings of days 1 and 2: 1. Measures of habitual and goal-directed learning will be button pushes in responses to computer-presented picture cues (abstract shapes) reflecting participants’ predictions about the stimuli (rewarding or neutral) associated with those cues. These are binary measures coded as either correct or incorrect and providing an averaged score of participant’s learning of the contingent relationships between cues and associated stimuli. The degree to which participants’ learning is driven by goal-directed as opposed to habitual (stimulus-driven) processes can be computed from an ensuing task in which the participants are requested to withhold predictions for stimuli that are no longer deemed rewarding. A measure of withholding (averaged across trials) is an index of the level of goal-directed behaviour. 2. Interoceptive measures relate both to cardiac and respiratory monitoring (heart rate, heart rate variability, respiratory rate) and to the participants’ ability to estimate their own heart rate (so-called “interoceptive awareness”). Interoceptive awareness scores are measured in terms of the level of accuracy obtained by participants in their estimates. These measures are taken on two occasions: on the morning of the first day of testing and on the morning of the second day. The relationship between scores on interoceptive awareness and goal-directed responding will be calculated by asking whether people who are more accurate on the former have a greater tendency to be goal-directed on the cue-stimulus learning task above. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. General cognitive function measured using task-induced blood oxygenation level signal which serves as a marker for regional brain activity as participants perform simple cognitive tasks over 1 h at approximately 3 pm on days 1 and 2 2. Eating behaviours measured using unobtrusive observation and measurement of the amount of calories consumed and the composition of foods chosen from a mixed buffet meal provided to participants at approximately 5 pm on days 1 and 2 | — |
Countries
United Kingdom
Outcome results
None listed