Accuracy of Dexcom G6® and FreeStyle Libre® Sensors in Standardized Hypoxemia Conditions

Inclusion Criteria: all population * No history of respiratory diseases (childhood asthma, respiratory allergies, exercise-induced asthma or dyspnea) * Willing to participate and able to sign an informed consent form (ICF) * Being affiliated with the French Social Security Inclusion Criteria:Patients with diabetes * type 1 diabetes mellitus or type 2 diabetes mellitus (ADA definition) * Age : 18 to 75 years * stable diabetes treatment for more than 3 months * no diabetic retinopathy * no diabetic neuropathy * no cardiovascular diseases * no contra-indication for coronary computed tomography angiography or myocardial perfusion scintigraphy. Inclusion Criteria: Healthy volunteers * Age : 18 ; 40 years * No diabetes * No persistant drug use \> 3 months except contraception * Body mass index : \[18,5 - 29,9\] kg/m2 Non-inclusion criteria : all population * Active smokers * Pregnant or breastfeeding women, women of childbearing age without effective contraception * Known allergies to the patch. * Skin lesions at the sensor site that may interfere with sensor placement or accuracy * Major cardiovascular complications within the past 3 months * Decompensated congestive heart failure * Chronic respiratory failure * Chronic renal failure * Resting ambient air O2 saturation ≤95%. * Treatment with systemic corticosteroids * Severe hypertension (≥180 mmHg systolic pressure or ≥ 100 mmHg diastolic pressure) * Any concomitant disease or condition that the investigator believes may compromise patient safety or affect the conduct of the study * Anemia (Hb\<12g/dl) * History of severe mountain sickness * Concurrent participation in another clinical research study, * Persons benefiting from enhanced protection Non-inclusion criteria: Patients with diabetes * Absolute contraindications to physical activity (HAS definitin) : * Pulmonary arterial hypertension (\> 60 mm Hg) * Presence of intra-cardiac thrombus * Acute pericardial effusion * Severe obstructive cardiomyopathy * Symptomatic aortic stenosis * Recent thrombophlebitis with or without pulmonary embolism