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.

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.

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)

prospective, monocentric study conduct in Toulouse university hospital