Inclusion Criteria - For all participants :  Age between 18 and 60 Non diabetic (fasting blood glucose <1.26 g/L) Patient not having objected to participating in the research  Inclusion Criteria - For the obese group with normal renal function  eDFG ≥ 60 ml/min/1.73 m2 BMI > 30 kg/m2 Microalbuminuria / creatinuria ≤ 3mg / mmol and / or proteinuria < 0.15 g/24h  Inclusion Criteria - For the obese group with impaired renal function  eDFG < 60 ml/min/1.73 m2 BMI > 30 kg/m2 Microalbuminuria / creatinuria ≤ 3mg / mmol and / or proteinuria < 0.15 g/24h  Inclusion Criteria - For the non-obese group with impaired renal function  eDFG < 60 ml/min/1.73 m2 BMI between 18 and 30 kg/m2 Microalbuminuria / creatinuria ≤ 3mg / mmol and / or proteinuria < 0.15 g/24h  Inclusion Criteria - For the non-obese group with normal renal function (control group)  eDFG ≥ 60 ml/min/1.73 m2 BMI between 18 and 30 kg/m2 Microalbuminuria / creatinuria ≤ 3mg / mmol and / or proteinuria < 0.15 g/24h  Exclusion Criteria - For all participants :  Acute renal failure within 3 months (defined as an increase of more than 50% in usual creatinemia) Inflammatory, infectious, cardiovascular or progressive neoplastic disease Urinary pathology (malformation, infection, etc.) Exclusion period of a previous study or already participating in a clinical research protocol having an impact on the judgment criteria of the study