Blood Glucose Target Before and During Exercise in Adults With Type 1 Diabetes Using an Artificial Pancreas (GUARDIA)

Evaluating the Appropriate Blood Glucose Target Before and During Moderate Intensity Aerobic Exercise in Adults With Type 1 Diabetes Using Do-it-yourself Automated Insulin Delivery (AID) Systems (the GUARDIA [GlUcose tARget DIY-AID] Trial)"

Despite major technological advances in type 1 diabetes (artificial pancreas), the management of hypoglycemia remains a major challenge, especially during and after physical activity. The primary outcome is to determine the temporary blood glucose (BG) target to be set 60 minutes before aerobic exercise in people with type 1 diabetes (PWT1D) using do-it-yourself automated insulin delivery (DIY-AID) systems. Three glycemic thresholds to be applied 60 minutes before physical activity will be tested in 32 people on AID-DIY: 8.3 (current target for commercial AID systems), 8.8, and 9.3 mmol/L. Each participant will perform 3 sessions of moderate aerobic physical activity (ergocycle) at 60% of vo2peak with a different glycemic target each time (random order). Plasma glucose will be measured every 20 minutes before and during physical activity, and blood glucose measured by continuous glucose reading (DEXCOM) for 24 hours post-intervention. Once the best glycemic target is selected, participants could come to the research center for 1 or 2 more voluntary interventions to test the threshold during 1) fasting exercise and 2) late luteal phase of the menstrual cycle.

Study Overview

• Status: Terminated
• Conditions: Type 1 Diabetes
• Intervention / Treatment: Other: Physical activity trial intervention

Detailed Description

This study follows a randomized, cross-over design and aims to test tree temporary BG targets (8.3, 8.8 and 9.3 mmol/L), resulting in 3 intervention visits per participants. A total of 32 participants will be recruited and randomized for this study.

Intervention visit:

• Participants will be admitted at the research center (IRCM; Montréal or Alberta) at 15:30.
• A venous catheter will be installed for plasma glucose and insulin measurements.
• At 16:00, the temporary BG target will be set in the DIY-AID system and blood sampling will begin.
• At 16:40, if glucose is < 5.5 mmol/L, 16g carbohydrate (CHO; 4 Dex4®) will be provided.
• At 16:55, a smaller sample will be taken only to verify glucose level. If glucose is < 5.5 mmol/L, 16g CHO (4 Dex4®) will be provided and exercise start will be postponed by at least 15 minutes or until glucose level is > 5.5 mmol/L. If more than three CHO intake are needed, the test will be canceled and rescheduled.
• At 17:00, exercise will be started if glucose is > 5.5 mmol/L. The exercise will consist of 60 minutes on the ergocycle at 60% of pre-determined VO2peak (moderate intensity).
• At 18:00, exercise and temporary BG target will be stopped. Blood sampling will continue for 1-hr during recovery.
• At 19:00, participant will be discharged. If glucose level is below 5.0 mmol/L, a snack of 16g CHO (4 Dex4®) will be offered. Participants will have the option to bring their dinner and eat it at the research facility before leaving if they prefer.

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H2W1R7
      • Institut de recherches cliniques de Montreal

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Males and females aged between 18 and 65 years old.
• Clinical diagnosis of type 1 diabetes for 1 year. (Note: The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed.)
• Treatment using DIY-AID system for 3 months.
• Own a smartphone or tablet to use the mobile application: Keenoa, Fitbit App
• Using Dexcom G6 and willing to share CGM data with the research team.
• Using rapid- (e.g., Aspart, Lispro or Glulisine) or ultra-rapid (e.g., FiAsp) acting insulin analogs.
• HbA1c < 8.5%.

Exclusion Criteria:

• Major complication within the previous 3 months (e.g., severe hypoglycemia requiring assistance, diabetic ketoacidosis, or cardiovascular event).
• Restriction in PA due to significant diabetes complications (e.g., severe peripheral neuropathy, active proliferative retinopathy, etc.) or other type of limitations (e.g., orthopedic, severe arthritis, etc.). Uncontrolled hypertension (e.g., blood pressure > 150 mmHg systolic or > 95 mmHg diastolic).
• Ongoing pregnancy or breastfeeding.
• Inability to give consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Temporary target of 8.3 mmol/L; Current commercial artificial pancreas thresholds. Temporary target set 60 minutes before the intervention.	Other: Physical activity trial intervention; 60 minutes aerobic ergocyle exercice at 60% VO2 Peak
Experimental: Temporary target of 8.8 mmol/L; Temporary target set 60 minutes before the intervention	Other: Physical activity trial intervention; 60 minutes aerobic ergocyle exercice at 60% VO2 Peak
Experimental: Temporary target of 9.3 mmol/L; Temporary target set 60 minutes before the intervention	Other: Physical activity trial intervention; 60 minutes aerobic ergocyle exercice at 60% VO2 Peak

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in plasma glucose during exercise	To determine the temporary blood glucose (BG) target to be set 60 minutes before aerobic exercise in PWT1D using DIY-AID systems which will be associated with the smallest change in glucose during exercise by testing the targets of 8.3 (current target for commercial AID systems), 8.8, and 9.3 mmol/L.	60 minutes (during exercice)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time in range during exercice: menstrual cycle phases	Volunteer participants will return in the luteal phase of the menstrual cycle to repeat the intervention at the glycemic threshold targeted during the primary outcome.	60 minutes (during exercice)
Time in range (during fasting exercice)	The intervention will be repeated at the glycemic threshold targeted during the primary outcome	60 minutes (during exercice)
Number of hypoglycemic episodes	number of hypoglycemic episodes (plasma glucose < 4.0 mmol/L) during exercise.	60 minutes (during exercice)
Number of participants who required oral treatment during exercise	Number of participants who required oral treatment during exercise for: a) plasma glucose value < 4.5 mmol/L and b) plasma glucose value < 4.0 mmol/L.	60 minutes (during exercice)
Lowest plasma glucose	Lowest plasma glucose level during exercise	60 minutes (during exercice)
Plasma glucose at 60 minutes	plasma glucose level at the end of exercise	60 minutes
Carbohydrate consumption (g)	amount of carbohydrate (CHO) needed to increase glucose value	60 minutes (during exercice)
Insulin on board (units)	Insulin on board or active insulin at exercise onset (Units will be collected on insulin pump) from start to finish	60 minutes (during exercice)
Plasma insulin	plasma insulin changes from exercise start to finish (uU/mL)	60 minutes (during exercice)
Percent time in range, in hypoglycemia and in hyperglycemia	Percentage of time < 3.0 mmol/L, between 3.0-3.9 mmol/L, between 3.9-10.0 mmol/L, between 10.1-13.9 mmol/L, and > 13.9 mmol/L post-exercice until 6 am	6 hours post-exercice
Percent time in range, in hypoglycemia and in hyperglycemia	Percentage of time < 3.0 mmol/L, between 3.0-3.9 mmol/L, between 3.9-10.0 mmol/L, between 10.1-13.9 mmol/L, and > 13.9 mmol/L post-exercice until 6 am	midnight to 6 am
Mean CGM glucose	post-exercice until 6 am	24 hours post-exercice
Glucose variability	post-exercice until 6 am; assessed by the CGM standard deviation	midnight to 6 am
Coefficient of variation	post-exercice until 6 am; assessed by the coefficient of variation	midnight to 6 am
Coefficient of variation	post-exercice until 6 am; assessed by the coefficient of variation	24 hours post-exercice
Glucose variability	post-exercice until 6 am; assessed by the CGM standard deviation	24 hours post-exercice
Number of participants requiring an oral treatment for hypoglycemia	Number of participants requiring an oral treatment for hypoglycemia (< 3.9 mmol/L) until 6 am.	midnight to 6 am
Number of participants requiring an oral treatment for hypoglycemia	Number of participants requiring an oral treatment for hypoglycemia (< 3.9 mmol/L) until 6 am.	24 hours post-exercice
Hypoglycemia with treatment	Total number of hypoglycemia episodes requiring treatment	24 hours post-exercice
Hypoglycemia with treatment	Total number of hypoglycemia episodes requiring treatment	midnight to 6 am
Carbohydrate needed (g)	total amount of carbohydrate (CHO) needed to treat hypoglycemic events.	midnight to 6 am
Carbohydrate needed (g)	total amount of carbohydrate (CHO) needed to treat hypoglycemic events.	24 hours post-exercice

Collaborators and Investigators

• Sponsor: Institut de Recherches Cliniques de Montreal
• Collaborators: University of Alberta
• Investigators: Principal Investigator: Rémi Rabasa-Lhoret, MD, PhD, IRCM

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Actual): March 31, 2025
• Study Completion (Actual): April 30, 2025

Study Registration Dates

• First Submitted: March 20, 2023
• First Submitted That Met QC Criteria: April 6, 2023
• First Posted (Actual): April 20, 2023

Study Record Updates

• Last Update Posted (Actual): March 5, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Hypoglycemia; Artificial pancreas; Exercice
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Autoimmune Diseases; Immune System Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Hypoglycemia; Diabetes Mellitus, Type 1
• Other Study ID Numbers: 2023-1223

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No