Feasibility Study of Closed Loop Control in Type 1 Diabetes Using Heart Rate Monitoring as an Exercise Marker

Inclusion Criteria

• ≥21 and 90 mmHg and/or systolic blood pressure >160 mmHg)
• Hematocrit 2 times the upper limit of normal
• Impaired renal function measured as creatinine >1.5 mg/dL
• Conditions which may increase the risk of hypoglycemia such as known coronary artery disease (e.g. history of myocardial infarction, acute coronary syndrome, therapeutic coronary intervention, coronary bypass or stenting procedure, stable or unstable angina, episode of chest pain of cardiac etiology with documented EKG changes, or positive stress test or catheterization with coronary blockages >50%), congestive heart failure, history of cerebrovascular event, seizure disorder, syncope, adrenal insufficiency, neurologic disease or atrial fibrillation
• Additional conditions which may inhibit the ability to perform exercise on a stationary bike (e.g. injury to or immobility of limbs, neuromuscular disease, exercise-induced asthma requiring inhaler use within the last 12 months or clinically impaired pulmonary function)
• Use of a medication that significantly lowers heart rate (beta blockers, reserpine, guanethidine, methyldopa, clonidine, cimetidine, digitalis, calcium channel blockers, amiodarone, antiarrythmic drugs, or lithium)
• History of a systemic or deep tissue infection with methicillin-resistant staph aureus or Candida albicans
• Use of a device that may pose electromagnetic compatibility issues and/or radiofrequency interference with the continuous glucose monitor (CGM) (implantable cardioverter-defibrillator, electronic pacemaker, neurostimulator, intrathecal pump, and cochlear implants)
• Medical condition requiring use of an acetaminophen-containing medication that cannot be withheld for the study admissions.
• Psychiatric disorders that would interfere with study tasks (e.g. inpatient psychiatric treatment within 6 months prior to enrollment, uncontrolled anxiety or panic disorder)
• Mental incapacity, unwillingness or language barriers precluding adequate understanding or cooperation
• Current or recent alcohol or drug abuse by patient history
• Medical conditions that would make operating a CGM, cell phone or insulin pump difficult (e.g. blindness, severe arthritis, immobility)
• Any skin condition that prevents sensor or pump placement on the abdomen or arm (e.g. bad sunburn, pre-existing dermatitis, intertrigo, psoriasis, extensive scarring, cellulitis)
• Known microvascular (diabetic) complications (other than diabetic non-proliferative retinopathy), such as history of laser coagulation, proliferative diabetic retinopathy, known diabetic nephropathy (other than microalbuminuria with normal creatinine) or neuropathy requiring treatment
• Active gastroparesis requiring current medical therapy
• 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
• Known bleeding diathesis or dyscrasia
• Known allergy to medical adhesives, components of the insulin pump insertion set or continuous glucose monitor sensor
• Anticoagulant therapy other than aspirin
• Oral steroids
• Active enrollment in another clinical trial
• Unwillingness to avoid acetaminophen while the continuous glucose monitor is in use.
• Unwillingness to withhold dietary supplements two weeks prior to admission and for the duration of the study participation.
• Subjects with basal rates less than 0.05.

Restrictions on use of other drugs or treatments

• Pramlintide, liraglutide and exenatide will be held for the duration of the study intervention.
• Oral steroids are excluded
• Anticoagulant therapy other than aspirin is excluded
• Acetaminophen will not be allowed while the continuous glucose monitor is in use
• Dietary supplements will be withheld two weeks prior to admission and for the duration of study participation
• Beta blockers, reserpine, guanethidine, methyldopa, clonidine, cimetidine, digi