Patient description: The patient is a 24-year-old man who has had type 1 diabetes for 11 years. He presents to the emergency room with hyperglycemia and concern for possible diabetic ketoacidosis after not taking his insulin for 3 days. The patient reports that he is currently homeless and has lost his supply of insulin, syringes, glucometer, and glucose testing supplies. The patient states that at the time of his initial diagnosis with type 1 diabetes he was hospitalized with a glucose value >1000 mg/dL. At the time, he was experiencing polyuria, polydipsia, and polyphagia. He reports that he has been on insulin since the time of his diagnosis, and he has never been prescribed oral agents for diabetes management. Most recently, he has been using insulin glargine 55 units once daily, and insulin aspart sliding scale 3 times daily. The patient has had previous episodes of diabetic ketoacidosis, for which he was hospitalized. With this episode of hyperglycemia, he is not experiencing any nausea, vomiting, or abdominal discomfort, and he appears well. His lab studies showed: A1c: 11.3% Creatinine: 0.9 mg/dL with eGFR >60 mL/min Aspartate aminotransferase (AST): 17 U/L Alanine aminotransferase (ALT): 14 U/L Beta-hydroxybutyrate: 0.1 mmol/L Bicarbonate: 25 mEq/L Anion

Clinical trial eligibility criteria: eligible ages (years): 21.0-65.0,  Type 1 Diabetes Mellitus Patient must be aged between 21 (inclusive) and 65 years old. The age of 21 has been chosen because this trial is supported by a US Foundation Patient must have been clinically diagnosed with Type 1 diabetes mellitus. For an individual to be enrolled at least one criterion from each list must be met for documented hyperglycemia (at least 1 must be met) Fasting glucose ≥126 mg/dL confirmed Two-hour Oral Glucose Tolerance Test (OGTT) glucose ≥200 mg/dL confirmed HbA1c ≥6.5% documented confirmed Random glucose ≥200 mg/dL with symptoms  Diabetic ketoacidosis within the 6 months prior to enrollment Severe hypoglycemia resulting in seizure or loss of consciousness in the 12 months prior to enrollment Pregnancy, breast feeding, or intention of becoming pregnant Uncontrolled arterial hypertension (diastolic blood pressure >90 mmHg and/or systolic blood pressure >160 mmHg) Conditions which may increase the risk of hypoglycemia such as uncontrolled coronary artery disease during the previous year (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 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 DexCom CGM (implantable cardioverter-defibrillator, electronic pacemaker, neurostimulator, intrathecal pump, and cochlear implants) Anticoagulant therapy other than aspirin Oral steroids Medical condition requiring use of an acetaminophen-containing medication that cannot be withheld for the study admissions