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

Institut de Recherches Cliniques de Montreal37 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Type 1 Diabetes

Interventions

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.

Single-hormone closed-loop strategyOTHER

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Percentage of time of plasma glucose levels spent below 3.9 mmol/L

Time frame: From 9:30 to 11:30 (120 minutes)

Secondary Outcomes

Relative decrease in glucose levels during exercise compared to pre-breakfast levels

Difference between pre-breakfast levels and the lowest glucose level from the start of the exercise until 20 minutes after exercise

Time frame: 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)

Decremental area under the curve from the start of the exercise

Time frame: 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)

Percentage of time of plasma glucose levels spent below 3.3 mmol/L

Time frame: 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)

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)

Percentage of time of plasma glucose levels spent above 10 mmol/L

Time frame: 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)

Percentage of time of plasma glucose levels spent above 16.7 mmol/L

Time frame: From 9:30 to 10:30 (60 minutes)

Mean plasma glucose levels

Time frame: From 8:00 to 11:30 (210 minutes)

Standard deviation of glucose levels

Time frame: From 8:00 to 11:30 (210 minutes)

Coefficient of variation of glucose levels

Time frame: 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)

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

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes