Feasibility Study of Closed Loop Control in Type 1 Diabetes Using Heart Rate Monitoring as an Exercise Marker
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
|Official Title:||Feasibility Study of Closed Loop Control in Type 1 Diabetes Using Heart Rate Monitoring as an Exercise Marker|
- Hypoglycemic Events [ Time Frame: 26 hours (x2 admissions) ]Plasma glucose based number of hypoglycemic events, defined as consecutive plasma readings below 70mg/dl to measure the capacity of the system to protect patients against the risk of hypoglycemia. Two events separated by only one Yellow Springs Instrument (YSI) value over 70 are considered to form a single event.
- Low Blood Glucose Index [ Time Frame: 26 hours (x2 admissions) ]
A measure of the risk of hypoglycemia. It quantifies the frequency and the extent of low BG readings.
A LBGI < 2.5 is associated with a low-risk of hypoglycemia, LBGI 2.5-5 is associated with a moderate risk of hypoglycemia, and LBGI > 5 is associated with a high-risk of hypoglycemia.
- Average Glucose Drop [ Time Frame: 26 hours (2x admissions) ]Average glucose drops at specific time points after the onset of exercise; defined as the difference between plasma glucose at onset of exercise and the glucose values reached at 40 and 60 min post onset of exercise.
- Time in Range [ Time Frame: 26 hours (x2 admissions) ]Percent time spent within target (70-180 mg/dL) range.
|Study Start Date:||May 2012|
|Study Completion Date:||August 2012|
|Primary Completion Date:||August 2012 (Final data collection date for primary outcome measure)|
Experimental: Experimental Condition: (Heart-Rate Informed SSM+HMM)
An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate
Device: Heart rate informed SSM+HMM
The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
No Intervention: Control Condition (SSM+HMM)
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
The combination of the Control to Range system and the cell phone is called the "Artificial Pancreas (AP) Platform". The purpose of this study is to see if this investigational technology can help control blood sugar in people with type 1 diabetes mellitus on insulin pump therapy can be successfully used and supervised in a hospital setting. This study is also being done to see if giving information about heart rate to the Closed-to-Range System can reduce hypoglycemia as it relates to exercise. Subjects will exercise on an exercise bike in the clinical research unit. During one exercise testing session, the Closed-to-Range System will receive information about your heart rate (Experimental Condition). During the other exercise testing session, the Control to Range System will not receive information about your heart rate (Control Condition). This part of the study is being done to see whether heart rate information helps the Closed-to-Range System reduce the occurrences of exercise-related hypoglycemia.
The Closed-to-Range system has two parts (modules) that can work together or separately.
A. The Safety Supervision Module (SSM) helps to prevent low blood sugars. It can reduce the amount of basal insulin that the pump is delivering and alert you if carbohydrates are needed to help prevent a low blood sugar. This module will be active at all times during the operation of the Closed-to-Range System.
B. The Hyperglycemia Mitigation Module (HMM) helps to prevent high blood sugars. It can instruct the insulin pump to deliver small boluses to help prevent high blood sugar. It can also help warn you of a possible pump problem if the blood sugar level is not responding to the insulin as it should.
The Closed-to-Range System works with the insulin pump and continuous glucose monitor to help keep the blood sugar in a desired range (80-180 mg/dL) during the day and help avoid hypoglycemia during the night.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01582139
|United States, Virginia|
|University of Virginia|
|Charlottesville, Virginia, United States, 22908|
|Principal Investigator:||Marc Breton, Ph.D.||University of Virginia Center for Diabetes Technology|