Four Way Crossover Closed Loop With Exercise Detection
Condition: Type 1 Diabetes
MeSH terms: Diabetes Mellitus, Type 1
Study type: Interventional

Summary: 
      Closed-loop systems are an emerging technology that automate hormone delivery. They are
      quickly paving the way to revolutionize the treatment of type 1 diabetes. Several categories
      have emerged: dual-hormone (insulin and glucagon) closed-loop systems and closed-loop systems
      with insulin only, one variety of which is the low glucose suspend safety feature now
      available from Medtronic (MiniMed 530G with Enlite). The study described within this protocol
      is designed to test the efficacy of a new closed-loop algorithm for managing blood glucose in
      people with type 1 diabetes before and after exercise. The new algorithm will have 3 modes: a
      single hormone insulin only mode, a dual-hormone insulin and glucagon mode and an insulin
      only mode with predictive low glucose suspend, all with an exercise detection algorithm. The
      purpose of this study is to determine whether a dual hormone AP with an exercise detection
      algorithm outperforms both single hormone AP and a low glucose suspend algorithm and sensor
      augmented pump therapy using the subject's own insulin pump.
    

Detailed description: 
      Subjects will undergo four approximately 84 hour studies. The first day of each study will be
      an approximately 12 hour inpatient visit to include activities of daily living and an
      exercise period with 2 days spent as an outpatient. The subject will come back to the
      research center on the fourth day to complete another approximately 12 hour inpatient visit
      to include activities of daily living and an exercise period followed by removal of all
      devices. In randomized order, subjects will have glucose controlled using the following
      systems: 1) dual-hormone closed-loop system, 2) insulin only closed-loop system, 3)
      predictive low glucose suspend system and 4) sensor augmented pump therapy with subject using
      their own insulin and insulin pump. Both of the closed-loop system algorithms have an
      exercise detection algorithm that uses inputs from a heart rate monitor and accelerometer,
      the Zephyrlife BioPatch. After exercise detection, insulin is turned off for the first 30
      minutes, the total insulin infusion rate is adjusted by an exercise multiplier, and for the
      dual-hormone system, the target glucose for glucagon is increased along with the maximum dose
      of glucagon allowed. The predictive low glucose suspend system will utilize the patient's
      optimized basal rates, correction factor, and carb ratio. The patient will bolus for meals
      and hyperglycemia as usual under PLGS, but will have the additional safety net of the pump
      suspending insulin when it predicts a hypoglycemic event. The Dexcom CGM system and the
      Tandem t:slim pumps will be used for all three intervention visits.

      Subjects will arrive at the CTRC at 7am at the start of intervention visits. Subjects will
      eat breakfast, lunch and dinner in the research center. Subjects will eat breakfast at
      8:30am. After breakfast, subjects will complete activities of daily living (sitting on a
      chair, lying on a bed, washing dishes, sweeping the floor, etc.). Subjects will eat lunch at
      12pm. Subjects will exercise for 45 minutes on a treadmill around 2pm. Subjects will eat
      dinner at 6pm and be discharged. The subject will then go home for Day 2 and Day 3 and return
      on Day 4 to complete another 12 hour inpatient visit with the schedule of activities
      identical to Day 1.
    

Intervention name(s): Artificial Pancreas Controller in Dual Hormone Mode; Subject's insulin pump; Artificial Pancreas Controller in Single Hormone Mode; Artificial Pancreas Controller in Predictive Low Glucose Suspend Mode
Intervention type(s): Device; Device; Device; Device
Intervention description(s): The artificial pancreas controller contains an algorithm for managing blood glucose in people with type 1 diabetes which includes an exercise detection component. The new algorithm will have 3 modes: a single hormone closed-loop insulin only mode, a dual-hormone closed-loop insulin and glucagon mode and an insulin only mode with predictive low glucose suspend. Closed-loop Artificial Pancreas Controller includes insulin and glucagon delivery algorithm implemented on a smart phone, utilizing sensor glucose values from a Dexcom G4 sensor and sending delivery commands to two Tandem t:slim insulin pumps, one filled with insulin and one with glucagon.; Subject will continue on their subcutaneous delivery of insulin on his/her own insulin pump using their own basal rates and carb ratios for meal boluses, managing their blood sugar as they normally would.; The artificial pancreas controller contains an algorithm for managing blood glucose in people with type 1 diabetes which includes an exercise detection component. The new algorithm will have 3 modes: a single hormone closed-loop insulin only mode, a dual-hormone closed-loop insulin and glucagon mode and an insulin only mode with predictive low glucose suspend. Closed-loop Artificial Pancreas Controller includes insulin delivery algorithm implemented on a smart phone, utilizing sensor glucose values from a Dexcom G4 sensor and sending delivery commands to one Tandem t:slim insulin pumps filled with insulin.; The artificial pancreas controller contains an algorithm for managing blood glucose in people with type 1 diabetes which includes an exercise detection component. The new algorithm will have 3 modes: a single hormone closed-loop insulin only mode, a dual-hormone closed-loop insulin and glucagon mode and an insulin only mode with predictive low glucose suspend. Closed-loop Artificial Pancreas Controller includes insulin delivery algorithm implemented on a smart phone, utilizing sensor glucose values from a Dexcom G4 sensor and sending delivery commands to one Tandem t:slim insulin pumps filled with insulin.
Other intervention name(s): APC
Intervention MeSH terms: Pancrelipase; Pancreatin; Hormones
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: diabetes; closed-loop; dual hormone; exercise