Impact of Obesity on Post-operative Cognitive Dysfunction: Role of Adipose Tissue

Study Overview
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Brief Summary
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This research aims at describing the relationship between white adipose tissue inflammation and post-operative cognitive dysfunctions.The possible link between inflammatory cytokines secretions of the white adipose tissue of a surgical wound and the arising of patient's cognitive dysfunction in the post-operative course will be investigated. The hypothesis is that obese patient's inflammation of the white adipose tissue leads to cognitive dysfunction.

Detailed Description
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The postoperative cognitive dysfunctions (POCD) are characterized by delirium and cognitive impairment. The delirium is defined by an acute altered attention with a fluctuating course. The post-operative cognitive impairment involves the early alteration of different functions including memory, attention and cognitive flexibility. POCD have a major impact in patient's morbidity. They are linked to the systemic inflammation induced by the surgical wound. The systemic inflammation leads to the rupture of the brain-blood barrier and to hippocampal inflammation. As hippocampus mediates the principal cognitive functions, hippocampal inflammation leads to POCD. Orthopedic and cardiac surgery are particularly concerned. Obesity is growing condition in the French population. It is linked to chronic systemic inflammation and altered cognitive functions. We think that obese people may present a susceptibility to POCD because of the pre-operative systemic inflammation.

Official Title
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Impact of Obesity on Post-operative Cognitive Dysfunction: Role of Adipose Tissue

Conditions
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Post-Operative Confusion, Obesity, Cognitive Impairment

Intervention / Treatment
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* Biological: Blood sampling
* Biological: white adipose tissue sampling


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patient about to receive a hip arthroplasty under general anesthesia, elective cardiac surgery with cardiopulmonary bypass, patient with a MMSE score > or = 20(/30), patient able to give informed consent Exclusion Criteria: emergency surgery, or surgery in a septic context, patient with a known dementia or altered MMSE score (under 20)

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Obese patients<br>BMI >30kg/m2 | Biological: Blood sampling<br>* 4 tubes of 7 mL of blood will be collected<br>Biological: white adipose tissue sampling<br>* At the beginning of the surgery, samples of white adipose tissue from the surgical wound will be collected.<br>|
| non obese patients<br>BMI between 18 to 29kg/m2 | Biological: Blood sampling<br>* 4 tubes of 7 mL of blood will be collected<br>Biological: white adipose tissue sampling<br>* At the beginning of the surgery, samples of white adipose tissue from the surgical wound will be collected.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arising of POCD measured by a composite criterion | 2 points Mini-Mental State Examination (MMSE) score decrease compared to the pre-operative score, and/or appearance of a delirium tracked down every day by the Confusion Assessment Method (CAM) during the hospital course. | day 5 after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation of inflammatory cytokine levels from patient's plasma and patient's white adipose tissue (extract from a controlled medium). | inflammatory cytokine levels will be measured in plasma and adipose tissue, and compared. | Day 0 and day 5 after surgery | 
| Identification of a linked between inflammatory cytokine levels and the appearance of POCD. | inflammatory cytokine levels will be measured in plasma and adipose tissue, and correlated with appearance of POCD | day 5 after surgery | 
| Peri-operative variations of the protein S100B, an autonomy scale (IADL) and a quality of life scale (EQ5D). | protein S100B levels will be measured in plasma and adipose tissue, and correlated with scores of autonomy scale (IADL) and quality of life scale (EQ5D). | day 5 after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Post-operative cognitive dysfunction, Inflammation, Inflammatory cytokines