Obesity, Morbid
Conditions
Keywords
bariatric surgery, Brain, Magnetic Resonance Imaging
Brief summary
Despite global efforts, the prevalence of obesity continues to rise, with rates in Canada tripling over the past three decades. In addition to the well-established risk of cardiometabolic conditions such as heart disease and diabetes, obesity has been associated with cognitive decline and an increased risk of dementia later in life. Sleeve gastrectomy, the most widely used surgical treatment for severe obesity, has proven effective in promoting significant weight loss and improving overall health. Emerging research, including our recent brain imaging study, suggests that this surgery may also have a positive impact on brain health. Our findings demonstrated significant improvements, with patients experiencing reductions in brain age by 2.9 and 5.6 years 12 and 24 months post-surgery, respectively. Despite these promising results, the long-term effects of sleeve gastrectomy on brain health and cognitive function remains poorly understood. While some patients experience cognitive improvements following surgery, others do not, and the factors driving this variability remain unknown. This proposal aims to comprehensively investigate the impact of bariatric surgery on brain health by examining its cognitive consequences, determinants, and drivers. Understanding the key factors that contribute to brain health improvements after bariatric surgery is essential for optimizing its benefits, preventing relapse and developing personalized interventions to maintain or enhance brain health in individuals living with obesity.
Interventions
PROCEDURESleeve Gastrectomy
Vertical sleeve gastrectomy
Sponsors
Laval University
Canadian Institutes of Health Research (CIHR)
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Women or men between 18 and 65 years who meet the Guidelines for bariatric surgery (BM I≥ 30 kg/m2 with major comorbidities or BMI ≥ 35 kg/m2
Exclusion criteria
* Pregnancy * Liver cirrhosis * Unstable medical, surgical or psychiatric conditions * Substance or alcohol abuse * Medications affecting the central nervous system * Previous gastric, oesophageal, brain, or bariatric surgeries * Gastrointestinal inflammatory diseases or ulcers * MRI contraindications
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Estimated Brain Age | Baseline to 36 months | Difference between MRI-predicted brain age and chronological age based (delta age, years) derived from a validated machine learning model based on MRI modalities. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Executive Function Composite Score | Baseline to 36 months | Composite z-score derived from the Stroop Color-Word Interference test, Trail Making Test Part B and Digit Span Test ( z-score change). |
| Change in Processing Speed Composite Score | Baseline to 36 months | Composite z-score derived from the Digit Symbol Substitution Test, Trail Making Test Part A, Stroop Color-Word Interference (z-score change). |
| Change in Memory Composite Score | Baseline to 36 months | Composite z-score derived from the Rey Auditory Verbal Learning Test (z-score change). |
| Change in Global Cognition | Baseline to 36 months | Montreal Cognitive Assessment (MoCA) score (0-30), with higher scores indicating better cognitive performance. |
| Change in White Matter Fractional Anisotropy (FA) | Baseline to 36 months | Mean fractional anisotropy (FA) derived from diffusion tensor imaging (dimensionless, 0-1); Higher FA values generally reflect greater white matter microstructural organization and fiber tract integrity. |
| Change in White Matter Mean Diffusivity (MD) | Baseline to 36 months | Mean diffusivity (MD; mm²/s) derived from diffusion tensor imaging. Higher MD values generally reflect reduced white matter microstructural integrity and increased water diffusion within tissue. |
| Change in Grey Matter Density | Baseline to 36 months | Grey matter density measured using voxel-based morphometry derived from T1-weighted structural MRI (arbitrary units). |
| Change in Grey Matter Cortical Thickness and Surface Area | Baseline to 36 months | Mean cortical thickness (mm) and total surface area (mm²) derived from T1-weighted MRI. |
| Change in White Matter Hyperintensity Volume | Baseline to 36 months | Total white matter hyperintensity volume (mm3) segmented from 3D FLAIR MRI. |
| Change in Cerebral Artery Diameter | Baseline to 36 months | Mean arterial lumen diameter (mm) measured in predefined cerebral arteries using TOF-MRA. |
| Change in Cerebral Artery Volume | Baseline to 36 months | Total cerebral arterial volume (mm³) measured from TOF-MRA using automated vessel segmentation. |
| Change in Cerebral Blood Flow | Baseline to 36 months | Regional and whole-brain cerebral blood flow (mL/100g/min) derived from ASL sequences. |
| Change in Brain Iron Content as Measured by QMRI Multi-Parameter Mapping Protocol | Baseline to 36 months | Magnetic susceptibility derived from quantitative susceptibility mapping (QSM), a surrogate marker of cerebral iron content (seconds). |
| Change in Brain Water Content as Measured by QMRI Multi-Parameter Mapping Protocol | Baseline to 36 months | Quantitative MRI estimate of brain Water content (%). |
| Change in Brain Myelin Integrity as Measured by QMRI Multi-Parameter Mapping Protocol | Baseline to 36 months | Myelin quantitative MRI measure (myelin water fraction, %). |
| Change in Body Mass Index | Baseline to 36 months | BMI (kg/m2) |
| Change in Percent Excess Weight Loss | Baseline to 36 months | Excess weight loss (%) |
| Change in Body Composition | Baseline to 36 months | Total weight (kg), Fat mass (kg) measured by bioimpedance or DXA. |
| Change in Adiposity | Baseline to 36 months | Waist, Hip and Neck circumference (cm). |
| Change in Glycemic Profile (blood samples) | Baseline to 36 months | Fasting glucose (mmol/L) |
| Change in HbA1c | Baseline to 36 months | HbA1c (%) |
| Change in Insulin (Blood samples) | Baseline to 36 months | Fasting Insulin (pmol/L) |
| Change in HOMA-IR index | Baseline to 36 months | HOMA-IR index (fasting glucose (mmol/L) x fasting insulin (pmol/L) / 135) |
| Change in Lipid Profile (blood samples) | Baseline to 36 months | Fasting Total Cholesterol (mmol/L), High Density Lipoprotein (HDL) cholesterol (mmol/L), Low Density Lipoprotein (LDL) cholesterol (mmol/L), Triglycerides (mmol/L), Apolipoprotein-B (g/L). |
| Change in Vascular Status | Baseline to 36 months | Systolic and diastolic blood pressure (mmHg). |
| Change in Inflammatory Cytokines (blood samples) | Baseline to 36 months | CRP (mg/L), IL-6 (pg/mL), LBP (g/mL), BDNF (pg/mL) |
| Change in Gastrointestinal Hormones (blood samples) | Baseline to 36 months | Postprandial GLP-1 (pg/mL) and fasting total ghrelin (pmol/L). |
| Change in Adipokines (blood samples) | Baseline to 36 months | Fasting Leptin concentration (ng/mL) |
| Change in Dietary Intake and Diet Quality Score (Web-based 24-hour dietary recall) | Baseline to 36 months | Healthy Eating Index (HEI) Score; Minimum: 0, Maximum: 100. |
| Change in Eating Behaviors (Three-Factor Eating Questionnaire) | Baseline to 36 months | The Three-Factor Eating Questionnaire (TFEQ) will be used to assess three dimensions of eating behavior: cognitive restraint of eating, uncontrolled/disinhibited eating, and susceptibility to hunger. The questionnaire generates subscale scores for each dimension, with higher scores indicating greater levels of the respective eating behavior construct. |
| Change in Eating Behaviors (Binge Eating Scale) | Baseline to 36 months | To assess the presence of certain binge eating behaviors that may be indicative of an eating disorder. The higher the score, the more binge eating behaviors is observed. The minimum score is 0 while the maximum score is 46. The final result allows to determine if the person has an absent (less than 17), moderate (between 18 and 26) or severe (more than 27) binging level. |
| Change in Quality of Life (Laval Questionnaire) | Baseline to 36 months | Laval questionnaire evaluating quality of life on 6 aspects on a scale from 0 to 7, higher scores indicate better quality of life. |
| Change in Depression and Anxiety Symptoms (Beck Depression Inventory) | Baseline to 36 months | Beck Depression Inventory. Evaluates severity of depressive symptoms using a validated questionnaire. Minimum score : 0; Maximum score : 63; Higher scores mean a worse outcome. |
| Change in Anxiety | Baseline to 36 months | General Anxiety Disorder questionnaire (GAD-7). Total score ranges from 0 to 21, with an increasing score on the scale is indicating a worse anxiety state. |
| Change in Quality of Sleep | Baseline to 36 months | Pittsburgh Sleep Quality Index questionnaire (PSQI) (19 self-assessment questions grouped into seven components). The scores for the seven components are summed to give an overall score that ranges from 0 to 21, with "0" indicating no difficulty and "21" indicating severe difficulty in all components. A score higher than 5 indicates problematic sleep in one or more components. |
| Change in Physical Activity | Baseline to 36 months | Physical activity measured using accelerometry. Outcomes include daily moderate-to-vigorous physical activity (minutes/day) and sedentary time (minutes/day). |
Countries
Canada
Contacts
CONTACTMélissa Pelletier, MSc
PRINCIPAL_INVESTIGATORAndréanne Michaud, DtP, PhD
Institut universitaire de cardiologie et de pneumologie de Québec, University Laval
Outcome results
None listed