Inclusion Criteria:

• Age 18-75 years
• Clinical diagnosis, based on investigator assessment, of T1D for at least one year and using insulin for at least 1 year.
• Using an insulin pump for diabetes therapy for at least 3 months
• Demonstration of proper mental status and cognition for the study
• Non-smoker
• If not currently using CGM, willing to use CGM during the study
• An understanding of and willingness to follow the protocol and sign the informed consent

Exclusion Criteria:

• Admission for diabetic ketoacidosis in the 6 months prior to enrollment unless study team feels the subject is appropriate for study given complete clinical context for subject
• Severe hypoglycemia resulting in seizure or loss of consciousness > once in the 6 months prior to enrollment
• History of a seizure disorder (except hypoglycemic seizure), unless written clearance is received from a neurologist and not currently on a seizure medication
• Cystic fibrosis
• Unstable coronary artery disease or heart failure, unless written clearance is received from a cardiologist or primary care provider
• A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol such as the following examples:
  1. Inpatient psychiatric treatment in the past 6 months
  2. Presence of a known adrenal disorder or chronic oral steroid therapy
  3. Abnormal liver function test results (Transaminase >3 times the upper limit of normal); testing required for subjects taking medications known to affect liver function or with diseases known to affect liver function
  4. Abnormal renal function test results (calculated GFR <60 mL/min/1.73m2);
  5. Active gastroparesis (defined actively being treated with medications)
• If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, lack of stability on the medication for the past 2 months prior to enrollment in the study
• Abuse of alcohol or recreational drugs
• Pregnancy
• Infectious process not anticipated to resolve prior to study procedures (e.g. meningitis, pneumonia, osteomyelitis).
• Uncontrolled arterial hypertension (Resting diastolic blood pressure >90 mmHg and/or systolic blood pressure >160 mmHg) at the time of screening
• Uncontrolled microvascular complications such as current active proliferative diabetic retinopathy defined as proliferative retinopathy requiring treatment (e.g. laser therapy) in the past 12 months.
• A recent injury to body or limb, muscular disorder, use of any medication, any carcinogenic disease, or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the protocol.