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NCT Number: NCT02855307

Closed-loop Control of Glucose Levels (Artificial Pancreas) During Postprandial 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.

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Key information

Conditions

Type 1 Diabetes Autoimmune Diseases Behavior Diabetes Mellitus Diabetes Mellitus, Type 1 Endocrine System Diseases Glucose Metabolism Disorders Hyperinsulinism Hypoglycemia Immune System Diseases Insulin Resistance Metabolic Diseases Motor Activity Nutritional and Metabolic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Institut de recherches cliniques de Montréal

Montreal, Quebec, H2W 1R7, Canada

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

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.
  • Use of medication with an effect on heart rate (e.g. beta-blockers).
  • Abnormal blood panel and/or anemia.
  • Ongoing or planned 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.

Treatment and study plan

60-minute exercise

Other

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.

Insulin pump

Device

Patient's insulin pump will be used to infuse insulin.

Dexcom G4 Platinum glucose sensor

Device

The Dexcom G4 Platinum glucose sensor will be used to measure glucose levels.

Insulin

Drug

Patient's usual fast-acting insulin analog will be used.

Single-hormone closed-loop strategy

Other

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.

Primary outcomes

  1. 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

  1. 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

  2. Number of patients experiencing exercise-induced hypoglycemia requiring treatment

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

  3. Decremental area under the curve from the start of the exercise

    Time frame: From 9:30 to 11:00 (90 minutes)

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

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

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

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

  6. Percentage of time of plasma glucose levels spent below 2.8 mmol/L

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

  7. 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)

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

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

  9. Percentage of time of plasma glucose levels spent above 13.9 mmol/L

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

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

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

  11. Mean plasma glucose levels

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

  12. Standard deviation of glucose levels

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

  13. Coefficient of variation of glucose levels

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

  14. Mean time (minutes) to the first hypoglycemic event

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

Sponsors and collaborators

Lead sponsor

Institut de Recherches Cliniques de Montreal

Other

Registry information

Official study title

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

Important dates

Study start
2016
Primary completion
2018
Study completion
2018
First posted
Aug 4, 2016
Registry last updated
Feb 11, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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