Four Way Crossover Closed Loop With Exercise Detection

Type 1 Diabetes Clinical Trial

Official title: A Randomized, Four-way, Cross-over Outpatient Study to Assess the Efficacy of a Dual-hormone Versus Insulin Alone Closed-loop System With Exercise Detection vs a Predictive Low Glucose Suspend System vs Current Care

Status Completed

Clinical Trial 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.

Clinical Trial 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. ;

Related Conditions & MeSH terms

• Diabetes Mellitus, Type 1
• Type 1 Diabetes

• NCT number: NCT02862730
• Study type: Interventional
• Source: Oregon Health and Science University
• Status: Completed
• Phase: N/A
• Start date: October 2016
• Completion date: January 31, 2018