Inclusion Criteria:  -For the patient population:  estimated GFR <60 ml / min / 1.73m2 according to the CKD-EPI formula OR patients dialyzed for more than 3 months No history of kidney transplant BMI between 18 and 30 kg / m² For women of childbearing age, at least one method of contraception recognized as effective Willing and able to give informed consent  For control group:  Potential living kidney donor Willing and able to give informed consent  For all of the study participants:  o Non diabetic (fasting blood glucose <1.26 g / L, or absence of insulin or oral antidiabetic treatment)  Exclusion Criteria:  For the patient population:  Subjects with a history of colectomy, gut resection or cholecystectomy Having received antibiotics, prebiotics, probiotics in the last 3 months. Taking a high dose laxative treatment (> 2 doses per day) in the last 3 months Hemoglobin <7 g / dl or <9 g / L in case of previous cardiovascular disease  For control group:  DFGe ≤ 80 ml / min / 1.73m2 according to CKD-EPI High blood pressure (PA≥140 / 90 mmHg) or taking antihypertensive treatment Presence of proteinuria (> 0.15 g / 24h) or micro-albuminuria (> 3 mg / mg creatinuria) or hematuria (> 20 GR / mm3)  For all of the study participants:  Hemoglobin <7 g / dl or <9 g / L in case of previous cardiovascular disease Active inflammatory, infectious, cardiovascular or neoplastic disease Period of exclusion from a previous study or already participating in a clinical research protocol having an impact on the study judgment criteria Exposure to ionizing radiation (medical radiological examinations or occupational exposure with exposure greater than 20 mSv) in the 6 months preceding inclusion No affiliation to social security Patient under guardianship or safeguarding justice Pregnant patient (a pregnancy test will be carried out for women of reproductive age o For the patients and control group will accept muscles biopsies Presence of a precarious venous capital that does not allow the placement of a venous catheter - Thrombocytopenia History of arrhythmias or cardiac conduction disorders Taking anticoagulant and / or antiplatelet agent Pulse <50 bpm Allergy to local anesthetics and / or plaster