Effect of Acute Hypoxia on Renal Hemodynamic in Healthy Volunteers, Patients With Diabetes and Patients With Diabetes and Kidney Disease

Inclusion Criteria: For all participant : 1. No history of respiratory diseases 2. Affiliated person or beneficiary of the French social security scheme. 3. signed informed consent Group 1 ( For healthy volunteers): 1. \[18; 40\] years old 2. No history of diabetes 3. No acute/long term \> 3 months drug use except contraception 4. BMI: \[18,5 - 29,9\]kg/m2 5. eGFR \> 60ml/min/1.73m2 6. Normal to midly increased albuminuria: defined as ACR \< 3 mg/mmol For all the patients with T2D (group 2 and 3): 1. Diagnosed T2D according to ADA criteria 2. \[35; 75\] years old 3. Stable treatment of diabetes and/or antihypertension for at least 2 months prior to inclusion 4. No proliferative diabetic retinopathy Group 2 - For patients with T2D and no DKD: * eGFR \> 60ml/min/1.73m2 and * Normal to midly increased albuminuria: defined as ACR \< 3 mg/mmol Group 3 - For patients with DKD: * eGFR \[45-60 ml/min/1.73m2\] and/or * Moderately to severely increased ACR ≥ 3 mg/mmol Exclusion Criteria: For all participants: 1. Active smoking 2. Contraindication to any of the agent (PAH, or iohexol or gadolinium) used in the study. 3. Contraindication to cardiac MRI, renal MRI, respiratory tests, 4. History acute coronary syndrome or coronary revascularization 5. Recent (\<6 months) history of: Heart failure requiring hospitalisation or Stroke or transient ischemic neurologic disorder 6. Severe unstable hypertension (≥180 mmHg systolic or ≥110 mmHg diastolic blood pressure) 7. Resting oxygen saturation \<95% at baseline 8. Any concomitant disease or condition that may interfere with the safety or the possibility for the patient to comply with or complete the study protocol. 9. History of severe mountain sickness (dizziness, headache, nausea/vomiting and incapaciting fatigue) 10. Consumption of SGLT2 inhibitors 11. Concurrent participation in another clinical research study 12. Pregnant or breastfeeding women, women of childbearing age who do not have effective contraception 13. Persons benefiting from enhanced protection under french national law 14. Persons under psychiatric care who are unable to give their consent