Tissue factor is the main activator of coagulation cascades. Excessive tissue factor expression is made responsible of thrombosis in a number of clinical situations including thrombosis in contact with atherosclerotic plaques. Recent work showed that tissue factor gene expression in adipose tissue was significantly increased in obese versus lean mice.

The main objective of this study is to show that tissue factor expression is increased in human adipose tissue obtained from obese subjects and to identify its main tissular origin by comparing abdominal and subcutaneous adipose tissue.

The secondary objectives are to identify the cell origin of tissue factor (adipocytes versus stromal cells) and to analyze the relation ship between blood tissue factor and (i) tissue factor expressed by adipose tissue, (ii) the amount of subcutaneous and profound adipose tissue, and (iii) coagulation activation markers.

Study design: it is a monocentric case/control study involving 60 obese subjects with a BMI  35 kg/m2 and 60 controls with a BMI between 18.5 and 25.

Inclusion Criteria:

• BMI > 35
• Stable obesity
• Abdominal or pelvic surgery
• Agree to participate to the study

Exclusion Criteria:

• malignancy,
• infectious or inflammatory disease, notably HIV infection
• pregnancy
• history of ischemic cardio or neurovascular event, lower limb arteritis