Preventing Hypoglycemia During Exercise With Proactive Snacking on Closed Loop

April 16, 2020 updated by: Jennifer Sherr, Yale University
This study is designed to look at how snacking during exercise may help prevent low blood sugars while subjects are on the "closed loop artificial pancreas." This system uses a continuous glucose sensor, an insulin pump, and a computer program that automatically determines how much insulin to give based on the sensor glucose level.

Study Overview

Detailed Description

This study will be a randomized cross-over study as subjects will be studied under both study conditions - Closed Loop (CL) alone vs. CL + proactive snacking protocol). Differences in the nadir blood glucose levels during exercise between the two study conditions will be the primary outcome measure.

Study Type

Interventional

Enrollment (Actual)

15

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Connecticut
      • New Haven, Connecticut, United States, 06520
        • Yale University School of Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

13 years to 44 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Age 13-45 years
  2. Clinical diagnosis of T1D (formal antibody and/or genetic testing will not be required)
  3. Duration of T1D ≥ 1 year
  4. HbA1c ≤ 9 %
  5. Treated with continuous subcutaneous insulin infusion (pump) for at least 3 months
  6. Body weight > 40 kg (to accommodate phlebotomy)
  7. Able to tolerate a 75-minute exercise period of moderate intensity
  8. Be willing to wear 2 subcutaneous glucose sensors (placed under the skin like a pump site) simultaneously during the inpatient portions of this study.
  9. Be in good general health without other acute or chronic illness that in the judgment of the investigator could interfere with the study or jeopardize subject safety
  10. Normal hematocrit
  11. Able to give consent (for children <18 years, permission from parents and subject assent will be required)
  12. Female subjects of reproductive potential must be abstinent or consistently using appropriate family planning methods.

Exclusion Criteria:

  1. Insulin resistant (defined as requiring > 1.5 units/kg/day at time of study enrollment)
  2. Presence of any medical or psychiatric disorder that may interfere with subject safety or study conduct
  3. Use of any medications (besides insulin) known to effect blood glucose levels, including oral or other systemic glucocorticoid therapy. Inhaled, intranasal, or rectal corticosteroid use is allowed along as not given within 2 weeks of the closed loop admissions. Use of topical glucocorticoids is allowable as long as affected skin area does not overlap with study device sites.
  4. Subjects using herbal supplements will be excluded, due to the unknown effects of these supplements on glucose control
  5. History of hypoglycemic seizure within last 3 months
  6. Female subjects who are pregnant, lactating, or unwilling to be tested for pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CL and exercise with proactive snacking
Subject will consume oral glucose prior to starting exercise regimen while on the Medtronic MiniMed Closed Loop (CL) System
The Medtronic MiniMed Closed Loop (CL) System is an investigational system that uses some commercially available products. An investigational Enlite 2 glucose sensor measures the sensor glucose. The glucose sensor signal is sent to the insulin pump. From the insulin pump the sensor glucose is sent through the translator, which then relays the signal on to a controller. An Android Mobile Device (off the shelf) has the control algorithm installed. This device is known as the controller. The controller serves as the control center for the Android system, receiving data from the sensor and pump components, feeding the data to its control algorithm, issuing delivery commands to the pump to apply the algorithm's recommend therapy, and providing a means to monitor the system.
Up to 45 g of oral glucose via Gatorade
Other Names:
  • Oral glucose
Active Comparator: CL and exercise without proactive snacking
Subject will not consume oral glucose prior to starting exercise regimen while on the Medtronic MiniMed Closed Loop (CL) System
The Medtronic MiniMed Closed Loop (CL) System is an investigational system that uses some commercially available products. An investigational Enlite 2 glucose sensor measures the sensor glucose. The glucose sensor signal is sent to the insulin pump. From the insulin pump the sensor glucose is sent through the translator, which then relays the signal on to a controller. An Android Mobile Device (off the shelf) has the control algorithm installed. This device is known as the controller. The controller serves as the control center for the Android system, receiving data from the sensor and pump components, feeding the data to its control algorithm, issuing delivery commands to the pump to apply the algorithm's recommend therapy, and providing a means to monitor the system.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Nadir blood glucose levels during exercise
Time Frame: 75 minutes
Difference in the nadir blood glucose levels during exercise between the two study conditions: Closed Loop alone vs. Closed Loop+ snacking.
75 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Episodes of hypoglycemia (blood glucose <60mg/dL) during exercise
Time Frame: 75 minutes
Percentage of subjects that required treatment for hypoglycemia during the exercise period between the two study conditions
75 minutes
Mean reduction in blood glucose during exercise
Time Frame: 75 minutes
Mean Reduction in blood glucose from baseline blood glucose during exercise
75 minutes
Mean time blood glucose in target during exercise
Time Frame: 75 minutes
Comparison of the mean time blood glucose levels were between 70-180mg/dL during exercise between the two study conditions
75 minutes
Mean time blood glucose levels are in target during the overnight period
Time Frame: 17 hours
Comparison of the mean time blood glucose levels are in target (70-180mg/dL) during the overnight period after mid-afternoon exercise.
17 hours
Mean glucose values
Time Frame: 12 hours
Comparison of the mean daytime and nighttime glucose values
12 hours
Mean 24- hour glucose levels
Time Frame: 24 hours
Comparison of the mean 24- hour glucose levels
24 hours
insulin delivery during CL therapy
Time Frame: 24 hours
Differences between insulin delivery during CL therapy during the two study conditions (pro-active snacking vs. no snacking) will be assessed.
24 hours
Incremental meal-related glucose Area Under the Curve
Time Frame: 24 hours
Assessment of incremental meal related glucose area under the curve will be conducted.
24 hours
Nadir glucose levels following the meals
Time Frame: 24 hours
Nadir glucose levels following meals will be compared between the two study conditions
24 hours
Area under the curve meal-related plasma insulin level excursion following meals
Time Frame: 24 hours
Area under the curve meal-related insulin excursion following meals.
24 hours
Nadir glucose levels overnight
Time Frame: 12 hours
Difference between nadir glucose levels between the two study conditions will be assessed.
12 hours
Mean absolute relative difference (MARD) for each sensor
Time Frame: 24 hours
Calculation and comparison of the mean absolute relative difference for each sensor will be performed and comparisons between accuracy of the sensors will be done.
24 hours
Mean daytime and nighttime glucose values
Time Frame: 24 hours
Comparison of the mean daytime and nighttime glucose levels
24 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Jennifer Sherr, MD, PhD, Yale University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2015

Primary Completion (Actual)

June 1, 2016

Study Completion (Actual)

December 1, 2016

Study Registration Dates

First Submitted

April 16, 2014

First Submitted That Met QC Criteria

May 7, 2014

First Posted (Estimate)

May 9, 2014

Study Record Updates

Last Update Posted (Actual)

April 20, 2020

Last Update Submitted That Met QC Criteria

April 16, 2020

Last Verified

April 1, 2020

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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