Obesity Nutritional, Metabolic, Endocrine
Conditions
Interventions
This cross-sectional observational study will compare patients with obesity either before or after bariatric surgery (gastric bypass or sleeve gastrectomy) and a group of healthy controls. Data will b
Sponsors
Champalimaud Foundation
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: The inclusion criteria for the healthy group are: 1. Aged between 18 and 65 years old 2. General good health as determined by the investigator The clinical sample consists of consecutive patients at a tertiary care outpatient centre specialised in the surgical treatment of obesity, belonging to Centro Hospitalar de Lisboa Ocidental, E.P.E., in Lisbon, Portugal. Patients are included in two groups: one group is of patients approved for bariatric surgery and on the waiting list (obese group) and the other is a group of patients that received bariatric surgery no less than 1.5 and no more than 4 years after either gastric bypass or sleeve gastrectomy (surgical group). In both groups, approval for bariatric surgery follows standard criteria as defined by the Portuguese National Health Service, namely: 1. Body mass index (BMI) greater than 40 Kg/m2 with or without associated comorbidities or greater than 35 Kg/m2 in the presence of at least 1 comorbidity (type 2 diabetes mellitus dyslipidemia, obstructive sleep apnea syndrome, obese hypoventilation syndrome, arterial hypertension or osteoarticular degenerative pathology, with marked functional limitation). 2. Age between 18 and 65 years 3. Failure of non-surgical interventions for weight reduction, for at least one year, obesity that is not secondary to an identified endocrine disease 4. Ability to understand the surgical procedure and to adhere to a long-term follow-up program 5. Absence of psychiatric disorders, absence of alcohol or drug dependence 6. Balanced relationship between operative risk and clinical risk
Exclusion criteria
Exclusion criteria: The exclusion criteria for healthy volunteers, assessed at entry into the study are: 1. Active acute respiratory infection 2. Active neurological or psychiatric disease 3. Active gastrointestinal, hepatic, or pancreatic disease 4. Diabetes 5. Illicit substance use or alcohol abuse 6. Use of any neuropsychiatric medication (including anxiolytics, antipsychotics, antidepressants, anticonvulsants, stimulants, anti-dementia medication, dopamine agonists and opioid pain relievers) or antidiabetic medication (including glp-1 agonists) 7. Obesity (BMI = 30 Kg/m2) or underweight (BMI < 18.5 Kg/m2) 8. Illiteracy, or otherwise not understanding instructions for the study 9. Prior major gastrointestinal surgery and/or intra-gastric balloon in the previous 12 months 10. History of food allergies 11. Pregnancy or breastfeeding Exclusion criteria for patients are equivalent to those mentioned above, except for obesity, and prior major gastrointestinal surgery (for the surgical group only).
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Changes in preference (%) for the conditioned stimulus (CS+) according to intake (g) from pre- to post-conditioning. Intake % preference for CS+ is calculated as [CS+ intake/ (CS- + CS+ intake) *100] measured using the weight of stimulus consumed, in g at post-conditioning day (day 6) relative to pre-conditioning day (day 1) | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Changes in preference (%) for CS+ according to pleasantness ratings (mm, gLMS) from pre- to post-conditioning. Pleasantness %preference for CS+ is calculated as [CS+ gLMS/ (CS- + CS+ gLMS) *100] measured using gLMS, in mm at post-conditioning day (day 6) relative to pre-conditioning day (day 1) 2. Striatal binding potential (BP) estimated as: (mean counts per voxel in the target area - counts per voxel in the reference region)/ counts per voxel in the reference region. The reference region is defined as a portion of the occipital lobe where D2 and D3 receptors are absent. The target area is defined as the striatum measured using IBZM single-photon emission computerized tomography (SPECT) on the post-conditioning day (day 6). The following main explanatory (independent) variables are assessed on pre-conditioning day (day 1) and/or post-conditioning day (day 6): 1. Feeding behavior traits measured using The Dutch Eating Behavior Questionnaire (DEBQ) 2. Food Acceptance measured using the Food Action Rating Scale (FARS) 3. Hedonic hunger measured using the Power of Food Scale (PFS) 4. Addiction-like feeding behavior measured using the Yale Food Addiction Scale (YFAS) 5. Intensity and pleasantness ratings given to 4 concentrations of citric acid (sour), sodium chloride (salty), sucrose (sweet) and quinine hydrochloride (bitter) measured using general labelled magnitude/hedonic scales (gLMS/ gLHS) 6. Acuity in tastant identification (sour, salt, sweet and bitter) measured using a multiple forced-choice test 7. Taste Thresholds measured using electrogustometry 8. Hunger and thirst ratings (fasted and post-prandial) measured using gLMS and a visual analogue scale (VAS) on pre and post-conditioning days 9. Hunger and thirst ratings (fasted) measured using gLMS and VAS during the conditioning days | — |
Countries
Portugal
Contacts
Public ContactAlbino Jorge Oliveira-Maia
Outcome results
None listed