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

Institut de Recherches Cliniques de Montreal

Status and phase: Completed; Phase 2

Conditions: Type 1 Diabetes

Treatments: Other: 60-minute exercise; Other: Single-hormone closed-loop strategy; Device: Insulin pump; Device: Dexcom G4 Platinum glucose sensor; Drug: Insulin

Study type: Interventional

Funder types: Other

Identifiers

NCT02855307

CLASS-16

Details and patient eligibility

About

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.

Enrollment: 37 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

---

37 participants in 3 patient groups

Unannounced exercise

Active Comparator group

Description:

The target blood glucose of the algorithm will be as usual. A pre-meal full insulin bolus will be given.

Treatment:

Other: 60-minute exercise

Device: Insulin pump

Drug: Insulin

Device: Dexcom G4 Platinum glucose sensor

Other: Single-hormone closed-loop strategy

Announced exercise with pre-meal full bolus

Active Comparator group

Description:

The target blood glucose of the algorithm will be increased and a pre-meal full bolus will be given

Treatment:

Other: 60-minute exercise

Device: Insulin pump

Drug: Insulin

Device: Dexcom G4 Platinum glucose sensor

Other: Single-hormone closed-loop strategy

Announced exercise with reduced insulin bolus

Active Comparator group

Description:

The target blood glucose of the algorithm will be increased and the pre-meal insulin bolus will be reduced by 33%.

Treatment:

Other: 60-minute exercise

Device: Insulin pump

Drug: Insulin

Device: Dexcom G4 Platinum glucose sensor

Other: Single-hormone closed-loop strategy