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

Phase 2

Completed

• Conditions: Type 1 Diabetes
• Interventions: Other: 60-minute exercise; Device: Insulin pump; Device: Dexcom G4 Platinum glucose sensor; Drug: Insulin; Other: Single-hormone closed-loop strategy

• Registration Number: NCT02855307
• Lead Sponsor: Institut de Recherches Cliniques de Montreal

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2016-08-01
• Study First Submitted QC: 2016-08-01
• Study First Posted: 2016-08-04
• Study Start: 2016-09
• Primary Completion: 2018-12
• Study Completion: 2018-12
• Status Verified: 2019-02
• Last Update Submitted: 2019-02-08
• Last Update Posted: 2019-02-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 37

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Unannounced exercise	Insulin	The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Announced exercise with reduced insulin bolus	Insulin	The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Unannounced exercise	Dexcom G4 Platinum glucose sensor	The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Announced exercise with reduced insulin bolus	Insulin pump	The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Announced exercise with pre-meal full bolus	Single-hormone closed-loop strategy	The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given
Announced exercise with reduced insulin bolus	60-minute exercise	The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Unannounced exercise	Insulin pump	The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Announced exercise with pre-meal full bolus	60-minute exercise	The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given
Announced exercise with pre-meal full bolus	Insulin pump	The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given
Announced exercise with reduced insulin bolus	Dexcom G4 Platinum glucose sensor	The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Announced exercise with reduced insulin bolus	Single-hormone closed-loop strategy	The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.
Unannounced exercise	60-minute exercise	The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Unannounced exercise	Single-hormone closed-loop strategy	The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.
Announced exercise with pre-meal full bolus	Dexcom G4 Platinum glucose sensor	The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given
Announced exercise with pre-meal full bolus	Insulin	The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given

Primary Outcome Measures

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

Secondary Outcome Measures

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

Trial Locations

Locations (1)

Institut de recherches cliniques de Montréal; 🇨🇦 Montreal, Quebec, Canada