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

Phase 2

Completed

Brief Summary: Closed-loop strategy 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. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormones: insulin and glucagon.

The objective is to compare the efficacy of single-hormone closed-loop strategy and dual-hormone closed-loop strategy at regulating glucose levels during continuous exercise and interval exercise.

The investigator hypothesized that dual-hormone closed-loop strategy is superior to single-hormone closed-loop strategy in regulating glucose levels during exercise periods.

Detailed Description: Closed-loop strategy 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. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormones: insulin and glucagon.

We aim to conduct a randomized two-way cross-over trial comparing single-hormone closed-loop strategy and dual-hormone closed-loop strategy to compare the two interventions during exercise periods in adults with type 1 diabetes. A moderate intensity exercise will be performed for 60 minutes at 60% of the maximum oxygen consumption (VO2max). A high intensity exercise will be 40 minutes of interval training. The interval training will be preceded by a 10 minutes warm-up and followed by a 10 minutes cool down.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

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.
Recent (< 3 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
Ongoing pregnancy.
Severe hypoglycemic episode within two weeks of screening.
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).
Failure to comply with team's recommendations (e.g. not willing to eat snack, not willing to change pump parameters, etc).
Problems with venous access

Arm && Interventions

Group	Intervention	Description
Single-hormone closed-loop system	60-minute exercise	In single-hormone closed-loop system, variable subcutaneous insulin infusion rate will be used to regulate glucose levels
Dual-hormone closed-loop system	60-minute exercise	In dual-hormone closed-loop system, variable subcutaneous insulin and glucagon infusion rates will be used to regulate glucose levels
Single-hormone closed-loop system	40-minute interval exercise	In single-hormone closed-loop system, variable subcutaneous insulin infusion rate will be used to regulate glucose levels
Dual-hormone closed-loop system	40-minute interval exercise	In dual-hormone closed-loop system, variable subcutaneous insulin and glucagon infusion rates will be used to regulate glucose levels

Primary Outcome Measures

Name	Time	Method
The number of patients experiencing exercise-induced hypoglycemia requiring dextrose infusion (< 3.3 mmol/L symptomatic or < 3.0 mmol/L regardless of symptoms).	18:00 hours to 19:30 hours

Secondary Outcome Measures

Name	Time	Method
Decrease in glucose levels during each exercise	18:00 to 19:30 hours or 18:00 to 19:10 depending on the exercise performed	Difference between glucose levels at the beginning of the exercise and the lowest glucose level from the start of the exercise until 30 minutes after exercise).
Percentage of time of plasma glucose levels < 4 mmol/L	15:30 hours to 19:30 hours
The amount of dextrose infused	15:30 to 19:30
Number of patients with an exercise-induced hypoglycemia < 3.9 mmol/L	15:30 hours to 19:30 hours
Percentage of time-in-target defined as between 4 and 10 mmol/L	15:30 hours to 19:30 hours
Mean time (minutes) to the first hypoglycemic event during the exercise period	18:00 to 19:00
Area under the curve of plasma glucose levels < 4 mmol/L	15:30 hours to 19:30 hours
Decremental area under the curve from the start of the exercise for 90 minutes.	18:00 to 19:30

Locations (1): Institut de recherches cliniques de Montréal
🇨🇦
Montreal, Quebec, Canada