Trial Review

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12621001653853
Ethics application status
Approved
Date submitted
15/11/2021
Date registered
1/12/2021
Date last updated
1/12/2021
Date data sharing statement initially provided
1/12/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
Optimising Exercise Preparation using Closed-loop Insulin Delivery for Exercise in People With Type 1 Diabetes
Scientific title
Advanced Hybrid Closed Loop (AHCL): Optimising the Timing of the Temporary Target Prior to Moderate Intensity and High intensity Exercise in People with Type 1 Diabetes
Secondary ID [1] 305801 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 1 Diabetes 324309 0
Condition category
Condition code
Metabolic and Endocrine 321799 321799 0 0
Diabetes
Physical Medicine / Rehabilitation 322003 322003 0 0
Other physical medicine / rehabilitation

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The purpose of this research study is to collect data that can help to answer questions about the performance of the Medtronic 780G artificial pancreas system during and post-exercise when a temporary glucose target is set at different time points pre-exercise. The study will compare glucose control in adults with type 1 diabetes in response to short-duration (40min) moderate intensity exercise, short-duration (40min) high-intensity exercise and long-duration (90min) moderate intensity exercise, when a temporary glucose target is set 60min pre-exercise, 20min pre-exercise, 0min pre-exercise, or when no temporary target is set.

Participation in this research study will occur over approximately 6-12 months. Participants will be required to attend the clinical trials centre at St Vincent’s Hospital, Melbourne on 17 occasions. To participate in this project, participants will need to be over 18 years of age, have been diagnosed with type 1 diabetes, and be currently using an insulin pump and have experience with continuous glucose monitoring devices.

Participation in this study will involve the completion of a maximal exercise capacity test, eight 40min moderate intensity exercise bouts, four 40min high-intensity exercise bouts and four 90min moderate intensity exercise bouts. Twelve of these exercise bouts will occur in the evening at ~5:00PM and four bouts will occur in the morning at ~8:00AM. Moderate intensity exercise involves continuous cycling on a stationary bicycle at an intensity where you are still able to maintain a conversation but is still more difficult than a leisurely walk. High intensity exercise is also on the stationary bicycle, but involves short bursts of hard exercise, separated by periods of rest. The intensity of the MIE will be continuous at 40% VO2max, while the HIE will involve intervals at 80% VO2max seperated by rest. All exercise sessions will be supervised by the study exercise physiologist.

The first visit to the clinical trials centre will be a screening session and will take approximately 2 hours, where we will obtain written consent, medical history, and collect some personal and physical data (such as height and weight). Additionally, participants will undergo a maximal exercise capacity test involving cycling on a stationary bicycle which progressively increases in intensity until fatigue after ~15 minutes. For the duration of this test there will be a mask fitted over the nose and mouth and which measures expired breath. If participants meet all of the criteria to be included in the study, they will be provided with the study insulin pump including the closed-loop (artificial pancreas) functionality, glucose sensors and study glucose meter. The insulin delivery device will be programmed with their insulin delivery settings and they will be educated in the use of the system.

Once participants have received the study devices, you will remain in manual mode on the insulin pump for at least 72 hours, after which they will enable the Smartguard feature (closed-loop mode), under direction of the study Diabetes Educator. They will remain in the closed-loop setting on the pump for at least 1 week before participating in the main experimental exercise visits. Following this screening sessions participants will continue to infuse insulin via the study device for the duration of the study.

Participants will attend the clinical trials center at ~17:00 on twelve occasions, and at ~08:00 on four occasions separated by at least one week (sixteen sessions total). On each day of evening exercise, participants will be asked to eat approximately four hours prior to the planned exercise and deliver your insulin bolus as usual. For morning exercise, participants will arrive prior to 09:00 having fasted overnight. Participants will set a temporary glucose target of 8.3mmol/L on the study insulin pump at one of four time-points pre-exercise for each bout of exercise: i) 60 min pre-exercise; ii) 20min pre-exercise; iii) at the onset of exercise; iv) no temporary set-point will be set and insulin delivery will continue as normal.

The mode/intensity (HIE vs MIE) and time of day of exercise (morning vs evening), as well as the allocation to the temporary target condition (i, ii, iii, iv) will occur in random order, as determined prior to participant enrollment via computerised randomizer.

Following each bout of exercise, participants will remain in the study centre for 90min post-exercise and will consume a provided, standardized meal consisting of 60g CHO, 20g protein and 20g fat.

Following completion of the 16 experimental testing sessions, the study devices will be returned to the study team.
Intervention code [1] 322198 0
Treatment: Devices
Comparator / control treatment
Current guidelines closed-loop insulin delivery suggest setting a temporarily elevated glucose target to reduce basal insulin delivery 60-120min prior to exercise. The current study is comparing glucose control when a temporary glucose target is set on the closed-loop system at 60min pre-exercise, 20min pre-exercise, 0min pre-exercise, or when no temporary target is set.
The control condition involves setting the temporary glucose target at the currently recommended 60-min pre-exercise and will be compared when the temporary target is set closer to exercise (20min, 0min or no temporary target).
Control group
Active

Outcomes
Primary outcome [1] 329564 0
The primary outcome is the total percent of continuous glucose monitoring (CGM) time spent in hypoglycaemia (<3.9 mmol/L) from the onset of exercise until the 2-hours following exercise completion.
Timepoint [1] 329564 0
The primary timepoint is from the onset of exercise until 2-hours post exercise completion
Secondary outcome [1] 403005 0
The percent of CGM time spent in target glycaemia ([a] 3.9-10.0 mmol/L and [b] 3.9-7.8 mmol/L) during the period from exercise commencement to 120 minutes post-exercise completion.
Timepoint [1] 403005 0
From the beginning of exercise until 2-hours post exercise completion
Secondary outcome [2] 403674 0
The percent of CGM time spent in hyperglycaemia (>10.0 mmol/L, >13.9mmol/L) during the period from exercise commencement to 120 minutes post-exercise completion.
Timepoint [2] 403674 0
The period from exercise commencement to 120 minutes post-exercise completion.
Secondary outcome [3] 403676 0
The percent of CGM time spent in hypoglycaemia (<3.9 mmol/L, <3.5 mmol/L, <3.0 mmol/L, and <2.8 mmol/L) during the period from exercise commencement to 120 minutes post-exercise completion.
Timepoint [3] 403676 0
The period from exercise commencement to 120 minutes post-exercise completion.
Secondary outcome [4] 403677 0
The combined mean CGM glucose and glycaemic variability (CV, MAGE) during the period from exercise commencement to 120 minutes post-exercise completion.
Timepoint [4] 403677 0
The period from exercise commencement to 120 minutes post-exercise completion.

Eligibility
Key inclusion criteria
Inclusion Criteria: Age greater than or equal to 18 years; T1D of >1-year duration; stable on insulin pump therapy for >3 months; proficient in carbohydrate counting; continuous glucose monitoring (CGM) sensor experience; HbA1c <10.0%; willing to have an adult experienced in the management of diabetes willing to live with them during the outpatient phase of the protocol.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion Criteria: Pregnancy; eGFR<40 ml/min/1.73m2; a history of diabetic ketoacidosis or of severe hypoglycemia in the last 3 months; diabetic gastroparesis; tape allergy; unable to exercise; major medical or psychiatric illness.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
6/12/2021
Actual
Date of last participant enrolment
Anticipated
6/06/2022
Actual
Date of last data collection
Anticipated
6/06/2023
Actual
Sample size
Target
32
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 310153 0
Commercial sector/Industry
Name [1] 310153 0
Medtronic
Country [1] 310153 0
United States of America
Primary sponsor type
Hospital
Name
St Vincent's Hospital Melbourne
Address
41 Victoria Parade, Fitzroy, VIC 3065
Country
Australia
Secondary sponsor category [1] 311232 0
None
Name [1] 311232 0
Address [1] 311232 0
Country [1] 311232 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 309842 0
St Vincent's Hospital Melbourne Human Research Ethics Committee
Ethics committee address [1] 309842 0
35 Victoria Parade, Fitzroy, VIC 3065
Ethics committee country [1] 309842 0
Australia
Date submitted for ethics approval [1] 309842 0
Approval date [1] 309842 0
10/11/2021
Ethics approval number [1] 309842 0

Summary
Brief summary
Regular physical activity has been clearly demonstrated to have a range of beneficial effects in people with and without diabetes, although in those people with type 1 diabetes this may come at the expense of increased risk of low blood sugar (or a hypo). This increased risk during exercise in individuals with type 1 diabetes occurs as insulin concentration cannot be decreased rapidly at the start of exercise, generally causing blood glucose levels to fall. On the other hand, very hard or intense exercise may cause blood glucose levels to rise. These differing responses to exercise of varying intensities makes generalizing recommendations for exercise difficult in people with type 1 diabetes.

A number of strategies are currently recommended to reduce the risk of exercise-induced low blood sugar (hypo), including reducing the meal-time insulin dose for meals close in timing to the beginning of exercise, or eating carbohydrates prior to and during exercise. However, these strategies often require the person with diabetes to actively plan in advance their exercise, and predict its intensity and duration, which is not always possible. Current guidelines for insulin delivery via an artificial pancreas suggest reducing insulin delivery by setting a temporary increased glucose target 60-120min prior to exercise (ie. Increasing the target on the pump from 5.5mmol to 8.3mmol).

However, it is important to consider the optimal timing for setting a temporary elevated glucose target using artificial pancreas systems. If good glucose control with very little high or low blood sugar can be achieved when the temporary glucose target is initiated closer to, or at the beginning of exercise, then this would make planning and undertaking exercise easier in people with type 1 diabetes.

The purpose of this research study is to collect data that can help to answer questions about the performance of the Medtronic 780G artificial pancreas system during and post-exercise when a temporary glucose target is set at different time points pre-exercise. The study will compare glucose control in adults with type 1 diabetes in response to short-duration (40min) moderate intensity exercise, short-duration (40min) high-intensity exercise and long-duration (90min) moderate intensity exercise, when a temporary glucose target is set 60min pre-exercise, 20min pre-exercise, 0min pre-exercise, or when no temporary target is set.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 115574 0
Prof David O'Neal
Address 115574 0
St Vincent's Hospital, 35 Victoria Pde, Fitzroy 3065 VIC
Country 115574 0
Australia
Phone 115574 0
+61 3 92882012
Fax 115574 0
Email 115574 0
[email protected]
Contact person for public queries
Name 115575 0
Dr Dale Morrison
Address 115575 0
St Vincent's Hospital, 35 Victoria Pde, Fitzroy 3065 VIC
Country 115575 0
Australia
Phone 115575 0
+61413137853
Fax 115575 0
Email 115575 0
[email protected]
Contact person for scientific queries
Name 115576 0
Dr Dale Morrison
Address 115576 0
St Vincent's Hospital, 35 Victoria Pde, Fitzroy 3065 VIC
Country 115576 0
Australia
Phone 115576 0
+61413137853
Fax 115576 0
Email 115576 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.