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NCT Number: NCT04031599

Assessment of the Efficacy of the Artificial Pancreas Combined With a Qualitative Meal Size Estimation to Control Postprandial Glucose Levels

Postprandial glycemic excursions are major determinants of overall glycemic control in type 1 diabetes. Carbohydrate content of ingested meals is the main determinant of post-meal glucose excursion. Accurate carbohydrate counting is a critical aspect of managing postprandial blood glucose levels. accurate carbohydrate counting is considered by patients as a significant burden and frustrating task.

The closed-loop system (CLS) 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 objective of this study is to compare the efficacy of two strategies to regulate glucose levels in outpatient settings in adults with type 1 diabetes: 1) single-hormone CLS with rapid acting insulin analogue combined with carbohydrate counting; 2) single-hormone CLS with rapid acting insulin analogue combined with simplified qualitative meal-size estimation.

A sub-study will also be proposed to participants. Postprandial exercise combines two situations complicating CLS operation: a high plasma insulin due to insulin on-board related to meal boluses and rapid blood glucose changes (postprandial blood glucose excursion and then drop during exercise) making input from the glucose sensor less accurate. The objective of this sub-study will be to explore the safety and efficacy of the CLS using the combined strategy of pre-meal exercise announcement and meal bolus reduction of 33% when exercise is performed 1 hour compared to 2 hours post meal time.

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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 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

Not applicable

Primary location

McGill University Health Center, Montreal, Quebec, Canada

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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 diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed.
  • The subject will have been on insulin pump therapy for at least 3 months.
  • Currently using, or willing to switch to Lispro U100 or Aspart for the duration of the study.
  • HbA1c < 10%.

Exclusion criteria

  • Clinically significant nephropathy, neuropathy (e.g. known or suspected gastroparesis) or retinopathy (e.g. proliferative retinopathy) as judged by the investigator
  • Recent (< 6 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery
  • Anticipated need to use acetaminophen during interventions with the closed-loop system
  • Pregnancy (ongoing or current attempt to become pregnant)
  • Breastfeeding
  • No nearby third party for assistance if needed (e.g. severe hypoglycemia glucagon treatment)
  • Plans to go abroad or travel at more than 3 hours distance from Montreal during the trial period
  • Severe hypoglycemic episode within two weeks of screening or during the run-in period
  • Severe hyperglycemic episode requiring hospitalization in the last 3 months
  • Current use of glucocorticoid medication (except low stable dose and inhaled steroids)
  • Agents affecting gastric emptying (Motilium®, Victoza®, Ozempic®, Trulicity®, Byetta® and Symlin®) as well as oral anti-diabetic agents (Metformin, Prandase®, DPP-4 inhibitors) if not at a stable dose for 3 months. Otherwise, these medications are acceptable and will be kept stable during the entire protocol.
  • Current use of SGLT-2 inhibitors unless at a stable dose for at least 3 months and appropriate ketone testing performed.
  • Known or suspected allergy to the trial products
  • Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator
  • Anticipation of a significant change in exercise regimen between admission and end of the trial (i.e. starting or stopping an organized sport)
  • In the opinion of the investigator, a participant who in unable or unwilling to observed the contraindications of the study devices

Treatment and study plan

Single-hormone closed-loop system

Device

Every 10 minutes, the glucose levels as measured by the sensor will be transferred automatically to a LG Google Nexus Smartphone that the algorithm is running on, which will calculate the recommended doses and will send them wirelessly to the infusion pump.

Insulin pump

Device

Tandem Diabetes Care

Continuous Glucose Monitoring System

Device

Dexcom G6

Aspart or Lispro

Drug

Aspart or lispro will be infused with the infusion pump

carbohydrate counting

Other

Participants will be required to enter an estimate of the carbohydrate content of their meal into the phone. Insulin boluses will be calculated based on grams of carbohydrates and participant's insulin-to-carbohydrate ratio. Carbohydrate-matching full prandial bolus will be given 5 to 10 minutes before the meal.

Simplified qualitative meal-size estimation strategy

Other

A pre-meal partial prandial bolus will be given 5-10 minutes before the meal. The partial bolus will be based on the estimated meal size (small, regular, large and extra-large). The closed-loop system will give the remaining insulin needed based on the sensor readings. For this strategy, meal size will be defined as: small as any meal less than 30g, regular meal as any meal between 30g and 60g CHO, large meal as any meal between 60g and 90g CHO, extra-large meal for anything above 90g CHO.

3-week intervention

Other

Glucose levels will be regulated by the single-hormone closed-loop system for 3 consecutive weeks.

1-hour postprandial exercise (sub-study)

Other

60 minute exercise will be started one hour after the meal time.

2-hour postprandial exercise (sub-study)

Other

60 minute exercise will be started two hours after meal time

Exercise announcement and meal bolus reduction (sub-study)

Other

Meal bolus reduction of 33% at meal time and exercise announcement (increased target glucose from 6 to 9mmolL) to the CLS algorithm

Primary outcomes

  1. Percentage of time of glucose levels spent between 3.9 and 10.0 mmol/L

    Time frame: 504 hours

  2. Relative decrease in glucose levels during exercise compared to pre-breakfast levels (sub-study)

    Time frame: 3.5 or 4.5 hours

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

Secondary outcomes

  1. Percentage of time of glucose levels spent between 3.9 and 7.8 mmol/L

    Time frame: 504 hours

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

    Time frame: 504 hours

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

    Time frame: 504 hours

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

    Time frame: 504 hours

  5. Percentage of time of glucose levels spent above 10.0 mmol/L

    Time frame: 504 hours

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

    Time frame: 504 hours

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

    Time frame: 504 hours

  8. Mean glucose levels

    Time frame: 504 hours

  9. Fasting glucose levels

    Time frame: 504 hours

  10. Standard deviation of glucose levels

    Time frame: 504 hours

  11. Standard deviation of insulin delivery

    Time frame: 504 hours

  12. Coefficient of variance of glucose levels

    Time frame: 504 hours

  13. Coefficient of variance of insulin delivery

    Time frame: 504 hours

  14. Between-day variability in glucose levels

    Time frame: 504 hours

  15. Between-day variability in insulin delivery

    Time frame: 504 hours

  16. Total insulin delivery

    Time frame: 504 hours

  17. Number of hypoglycemic events less than 3.1 mmol/L

    Time frame: 504 hours

  18. Number of nights with hypoglycemic events less than 3.1 mmol/L

    Time frame: 126 hours

  19. Number of days with hypoglycemic events less than 3.1 mmol/L

    Time frame: 252 hours

  20. Total number of hours of sensor availability

    Time frame: 378 hours

  21. Percentage of time of sensor availability

    Time frame: 504 hours

  22. 2-hour postprandial glucose levels over the last 3 days of the intervention.

    Time frame: 18 hours

  23. Average number of days per participant requiring study team support for at least one technical problem

    Time frame: 21 days

  24. Number of hours and percentage of time in open-loop and closed-loop modes

    Time frame: 504 hours

  25. Average number of phone calls per participant related to CLS technical issues

    Time frame: 504 hours

  26. Decrease in plasma glucose levels during exercise (sub-study)

    Time frame: 1 hour

    Difference between glucose levels at the beginning of the exercise and the lowest glucose levels from the start of the exercise until the end of exercise

  27. Relative decrease in glucose levels during exercise compared to pre-breakfast levels (sub-study)

    Time frame: 2 or 3 hours

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

  28. Percentage of time of plasma glucose levels spent below 3.9 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  29. Percentage of time of plasma glucose levels spent below 3.3 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  30. Percentage of time of plasma glucose levels spent below 3.0 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  31. Percentage of time of plasma glucose levels spent between 3.9 and 10.0 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  32. Percentage of time of plasma glucose levels spent above 10.0 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  33. Percentage of time of plasma glucose levels spent above 13.9 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  34. Percentage of time of plasma glucose levels spent above 16.7 mmol/L (sub-study)

    Time frame: 1 or 2 hours

    Pre-exercise period (from mealtime to exercise onset)

  35. Percentage of time of plasma glucose levels spent below 3.9 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  36. Percentage of time of plasma glucose levels spent below 3.3 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  37. Percentage of time of plasma glucose levels spent below 3.0 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  38. Number of patients experiencing hypoglycemia requiring treatment (sub-study)

    Time frame: 1 hour

    Exercise period

  39. Percentage of time of plasma glucose levels spent between 3.9 and 10.0 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  40. Percentage of time of plasma glucose levels spent above 10.0 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  41. Percentage of time of plasma glucose levels spent above 13.3 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  42. Percentage of time of plasma glucose levels spent above 16.7 mmol/L (sub-study)

    Time frame: 1 hour

    Exercise period

  43. Percentage of time of plasma glucose levels spent below 3.9 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  44. Percentage of time of plasma glucose levels spent below 3.3 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  45. Percentage of time of plasma glucose levels spent below 3.0 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  46. Percentage of time of plasma glucose levels spent between 3.9 and 10.0 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  47. Percentage of time of plasma glucose levels spent above 10.0 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  48. Percentage of time of plasma glucose levels spent above 13.3 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  49. Percentage of time of plasma glucose levels spent above 16.7 mmol/L (sub-study)

    Time frame: 1.5 hour

    Post-exercise period

  50. Number of patients experiencing hypoglycemia requiring treatment (sub-study)

    Time frame: 3.5 or 4.5 hours

    Overall study period

  51. Mean time (minutes) to the first hypoglycemic event (sub-study)

    Time frame: 1 hour

    Exercise period

Sponsors and collaborators

Lead sponsor

Institut de Recherches Cliniques de Montreal

Other

Registry information

Official study title

An Open-label, Randomized, Crossover Trial to Assess the Efficacy of Single-hormone Closed-loop System With a Rapid Acting Insulin Analogue Combined With Either Conventional Carbohydrate Counting or a Simplified Qualitative Meal-size Estimation in Regulating Glucose Levels in Adults With Type 1 Diabetes

Important dates

Study start
2020
Primary completion
2021
Study completion
2021
First posted
Jul 24, 2019
Registry last updated
Jan 28, 2022

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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