Kidney Function Indexed Extracellular Volume Before and After Obesity Surgery

Inclusion Criteria

• •Topic GFR estimated by having the simplified formula of MDRD \<60 ml / min / 1.73 m²
• •Topic with BMI ≥ 40 kg / m², or ≥ 35 kg / m²
• •Subject having at least one comorbidity could be improved after surgery after failure of medical treatment: hypertension , OSAHS and other severe respiratory disorders, severe metabolic disorders, particularly type 2 diabetes , debilitating musculoskeletal diseases, steatohepatitis nonalcoholic .
• •Topic who signed the informed consent
• •Topic affiliated to the social security
• •Male or female Topics
• •Elderly 18 to 70 inclusive