Adjusted Value of Thromboprophylaxis in Hospitalized Obese Patients: A Comparative Study of Two Regimens of Enoxaparin

Inclusion Criteria: 1. Patient aged ≥ 18 ans. 2. Signed inform consent 3. Obesity defined by a BMI value ≥ 30 kg/m2. 4. Hospitalized for : * acute medical affection such as : * congestive heart failure (stage III or IV NYHA), * severe respiratory disease, * Infectious disease or acute rheumatologic disorder or inflammatory bowel disease with one or more additional risk factors, including active cancer, previous VTE, age \> 75 y-o, estrogen therapy, chronic heart failure or chronic respiratory disease * or recent myocardial infarction(\< 6 weeks), recent stroke with hemiparesis (\< 15 days), previous VTE, myeloproliferative syndrome associated with one or more additional risk previously cited. 5. Affiliation to a welfare system. Exclusion Criteria: 1. Subjects unwilling or unable to comply with study procedures 2. History of hypersensitivity to enoxaparin heparin induced thrombocytopenia 3. Previous history of heparin induced thrombopenia 4. acquired or inherited bleeding diathesis or coagulopathy, 5. Platelet count \< 50.000 G/L, 6. History of clinically significant bleeding 7. Severe renal insufficiency with CrCl \<30 ml/min (Cockcroft method), 8. Pregnancy or breastfeeding 9. Women without contraceptive methods 10. Severe peripheral arterial disease (Ankle blood pressure \<50mm Hg) 11. Concomitant anticoagulant therapy 12. Severe psychiatric disease 13. History of disease or psychological or sensory anomaly susceptible to prevent the subject to understand indeed the conditions required for his participation to the protocol or preventing him from giving its enlightened consent 14. Person deprived of liberty by an administrative or judicial decision, or person under legal guardianship person 15. Patient participating to a trial or having participated in another medicinal trial within 1 month