Closed-loop Control of Glucose Levels (Artificial Pancreas) During Postprandial Exercise in Adults With Type 1 Diabetes

February 8, 2019 updated by: Rémi Rabasa-Lhoret, Institut de Recherches Cliniques de Montreal

A Single-blind, Randomized, Cross-over Study to Assess the Efficacy of Single-hormone Closed-loop Strategy at Preventing Hypoglycemia During Unannounced and Announced Exercise in Adults With Type 1 Diabetes

Regular physical activity is associated with many health benefits for individuals with type 1 diabetes including improved cardiovascular fitness and vascular health, decreased insulin requirements, improved body composition and quality of life. However, exercise-induced hypoglycemia is very frequent and thus is the main limiting factor for physical activity practice in this population.

The artificial pancreas is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required insulin dosages based on the sensor's readings. The artificial pancreas has the potential to reduce the risk of exercise-induced hypoglycemia but the importance of announcing exercise to the artificial pancreas is yet to be explored.

The objective of this study is to investigate 1) if announcing postprandial exercise to the artificial pancreas is beneficial in reducing the risk of hypoglycemia and 2) if an insulin bolus reduction is necessary when announcing the exercise to the artificial pancreas.

Study Overview

Study Type

Interventional

Enrollment (Actual)

37

Phase

  • Phase 2

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

    • Quebec
      • Montreal, Quebec, Canada, H2W 1R7
        • Institut de recherches cliniques de Montreal

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Males and females ≥ 18 years of old.
  2. Clinical diagnosis of type 1 diabetes for at least one year.
  3. The subject will have been on insulin pump therapy for at least 3 months.
  4. Last (less than 3 months) HbA1c ≤ 12%.

Exclusion Criteria:

  1. Clinically significant microvascular complications: nephropathy (estimated glomerular filtration rate below 40 ml/min), neuropathy (especially diagnosed gastroparesis) or severe proliferative retinopathy as judged by the investigator.
  2. Recent (< 3 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
  3. Use of medication with an effect on heart rate (e.g. beta-blockers).
  4. Abnormal blood panel and/or anemia.
  5. Ongoing or planned pregnancy.
  6. Severe hypoglycemic episode within two weeks of screening.
  7. Other serious medical illness likely to interfere with study participation or with the ability to complete the exercise periods by the judgment of the investigator (e.g. orthopedic limitation).
  8. Failure to comply with team's recommendations (e.g. not willing to eat snack, not willing to change pump parameters, etc).
  9. Problems with venous access.

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: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Unannounced exercise
The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Patient's usual fast-acting insulin analog will be used.
The Dexcom G4 Platinum glucose sensor will be used to measure glucose levels.
Patients will be admitted at the research clinical facility at 6:30. The artificial pancreas intervention will start at 7:00. A standardized breakfast will be served at 8:00. At 9:30, patients will performed a 60-minute exercise on the ergocycle at 60% of VO2 max. At 11:30, patients will be switched to standard insulin pump therapy and a lunch will be served. Patients will be discharged after lunch consumption.
Patient's insulin pump will be used to infuse insulin.
Variable subcutaneous insulin infusion rates will be used to regulate glucose levels. Patient's usual fast acting insulin analog (Lispro, Aspart or Guilisine) will be infused using the patient's pump. The glucose level as measured by the real time sensor (Dexcom G4 Platinum, Dexcom Inc.) will be entered manually into the computer every 10 minutes. The pump's infusion rate will then be changed manually based on the computer generated recommendation infusion rates.
Active Comparator: Announced exercise with pre-meal full bolus
The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given
Patient's usual fast-acting insulin analog will be used.
The Dexcom G4 Platinum glucose sensor will be used to measure glucose levels.
Patients will be admitted at the research clinical facility at 6:30. The artificial pancreas intervention will start at 7:00. A standardized breakfast will be served at 8:00. At 9:30, patients will performed a 60-minute exercise on the ergocycle at 60% of VO2 max. At 11:30, patients will be switched to standard insulin pump therapy and a lunch will be served. Patients will be discharged after lunch consumption.
Patient's insulin pump will be used to infuse insulin.
Variable subcutaneous insulin infusion rates will be used to regulate glucose levels. Patient's usual fast acting insulin analog (Lispro, Aspart or Guilisine) will be infused using the patient's pump. The glucose level as measured by the real time sensor (Dexcom G4 Platinum, Dexcom Inc.) will be entered manually into the computer every 10 minutes. The pump's infusion rate will then be changed manually based on the computer generated recommendation infusion rates.
Active Comparator: Announced exercise with reduced insulin bolus
The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Patient's usual fast-acting insulin analog will be used.
The Dexcom G4 Platinum glucose sensor will be used to measure glucose levels.
Patients will be admitted at the research clinical facility at 6:30. The artificial pancreas intervention will start at 7:00. A standardized breakfast will be served at 8:00. At 9:30, patients will performed a 60-minute exercise on the ergocycle at 60% of VO2 max. At 11:30, patients will be switched to standard insulin pump therapy and a lunch will be served. Patients will be discharged after lunch consumption.
Patient's insulin pump will be used to infuse insulin.
Variable subcutaneous insulin infusion rates will be used to regulate glucose levels. Patient's usual fast acting insulin analog (Lispro, Aspart or Guilisine) will be infused using the patient's pump. The glucose level as measured by the real time sensor (Dexcom G4 Platinum, Dexcom Inc.) will be entered manually into the computer every 10 minutes. The pump's infusion rate will then be changed manually based on the computer generated recommendation infusion rates.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percentage of time of plasma glucose levels spent below 3.9 mmol/L
Time Frame: From 9:30 to 11:30 (120 minutes)
From 9:30 to 11:30 (120 minutes)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Relative decrease in glucose levels during exercise compared to pre-breakfast levels
Time Frame: From 8:00 to 10:50 (170 minutes)
Difference between pre-breakfast levels and the lowest glucose level from the start of the exercise until 20 minutes after exercise
From 8:00 to 10:50 (170 minutes)
Number of patients experiencing exercise-induced hypoglycemia requiring treatment
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Decremental area under the curve from the start of the exercise
Time Frame: From 9:30 to 11:00 (90 minutes)
From 9:30 to 11:00 (90 minutes)
Percentage of time of plasma glucose levels spent below 3.9 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent below 3.3 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent below 2.8 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent between 3.9 and 7.8 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent above 10 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent above 13.9 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Percentage of time of plasma glucose levels spent above 16.7 mmol/L
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)
Mean plasma glucose levels
Time Frame: From 8:00 to 11:30 (210 minutes)
From 8:00 to 11:30 (210 minutes)
Standard deviation of glucose levels
Time Frame: From 8:00 to 11:30 (210 minutes)
From 8:00 to 11:30 (210 minutes)
Coefficient of variation of glucose levels
Time Frame: From 8:00 to 11:30 (210 minutes)
From 8:00 to 11:30 (210 minutes)
Mean time (minutes) to the first hypoglycemic event
Time Frame: From 9:30 to 10:30 (60 minutes)
From 9:30 to 10:30 (60 minutes)

Collaborators and Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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

September 1, 2016

Primary Completion (Actual)

December 1, 2018

Study Completion (Actual)

December 1, 2018

Study Registration Dates

First Submitted

August 1, 2016

First Submitted That Met QC Criteria

August 1, 2016

First Posted (Estimate)

August 4, 2016

Study Record Updates

Last Update Posted (Actual)

February 11, 2019

Last Update Submitted That Met QC Criteria

February 8, 2019

Last Verified

February 1, 2019

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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