Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12621000889853
Ethics application status
Approved
Date submitted
2/06/2021
Date registered
8/07/2021
Date last updated
24/03/2024
Date data sharing statement initially provided
8/07/2021
Date results information initially provided
24/03/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Glycaemic outcomes in people with type 2 diabetes initiating continuous glucose monitoring: The 2GO-CGM study
Scientific title
Effect on glycaemic outcomes in people with type 2 diabetes initiating continuous glucose monitoring: The 2GO-CGM study
Secondary ID [1] 304202 0
HRS (sponsor issued) ID: 01762
Universal Trial Number (UTN)
U1111-1264-5822
Trial acronym
2GO-CGM
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 diabetes 321889 0
Condition category
Condition code
Metabolic and Endocrine 319620 319620 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a multi-site, 12-week randomized controlled trial (RCT), followed by a 12-week continuation phase where those initially randomized to routine care cross over into the continuous glucose monitoring (CGM) intervention. This study will explore the effect of initialising CGM on glycaemic outcomes in patients with type 2 diabetes. The Dexcom G6 CGM system is being used in this study, which is already commercially available in New Zealand. All participants will be involved in the RCT for 26 weeks. The main study will be followed by a 12-month extension study, where those who volunteer to participate will use the CGM system for further 12 months. Participants who decide to take part in the extension study will be involved for a total of 18 months. The study will enrol 80 people with type 2 diabetes aged 16 years and over, who have suboptimal glycaemic control and inject insulin daily. Following consent, baseline data will be collected from eligible subjects during the initial clinic visit (up to 4 hours). Subjects will wear a blinded Dexcom G6 CGM system for 14 days, where the glucose values will not be shown to the participants. Following this run-in period of 14 days to collect baseline glycaemic values participants will be randomized to the control arm and continue their usual finger prick glucose monitoring, or to the intervention arm and use Dexcom G6.
Participants randomized to the intervention arm will be trained on CGM use during a 3-4-hour session by trained research staff (research nurses/doctors with diabetes knowledge), and this will be combined with a diabetes management/insulin titration algorithm. Each Dexcom G6 CGM sensor can be worn for up to 10 days, and a new sensor can easily be applied by the participants themselves. The Dexcom G6 CGM system consists of (1) a sensor worn on the upper arm or abdomen that measures the glucose concentration in the interstitial fluid, (2) a transmitter that send the results wirelessly and (3) a handheld receiver, that receives and displays the glucose data. Through this receiver, CGM glucose data will be uploaded by participants to the cloud-based Dexcom CLARITY software throughout the study, and research staff will use this information to assess sensor use during the study. Throughout the 12-week RCT phase, participants will be contacted by research staff at weeks 2 and 8 to review and if required adjust the insulin titration plan as indicated by the self-management algorithm. Furthermore, all participants will be asked to complete a food diary at home on four days during both the first and the last week of the RCT phase. During the same time, sleep quality will be measured using questionnaires and actigraphy. Following the primary end-point, those in the control arm will be trained on CGM in the same way the intervention arm was originally trained and use the CGM system for 12 weeks. The intervention arm will continue Dexcom G6 use for a further 12 weeks to see if any improvements are ongoing or sustained, and allow for a longer data collected for adverse events, which occur at a very low rate. After completion of the main study, all participants will be invited into the 12-month extension study to collect longitudinal data in this population group. During the 12-month extension phase, the participants may be upgraded to the new Dexcom G7, as soon as this system is available. The Dexcom G7 is significantly smaller, has a simplified insertion process and a shorter sensor warm-up time compared to the G6 model. Any use of the Dexcom G7 would only be in the extension phase and will not induce any bias into the results given there are no differences in the glucose monitoring between the models. Those who consent to take part in this 12-month extension will visit the clinic after 6 months for a follow-up check and data collection and 12 months for final data collection (up to 3 hours).
The insulin titration algorithm is depended on the participant's diabetes treatment (basal insulin only; basal plus regimen; basal bolus regimen; once daily premixed insulin; twice daily premixed insulin). Participants will be provided with individualised plans for self-titration of their insulin regimen. Adherence and safety of self-titration will be checked at each study visit and remote review by diabetes research nurses. Prandial insulin (either rapid-acting or premixed insulin as appropriate) will be encouraged at all meals where there is a consistent > 3 mmol/L increase in glucose levels for 2 – 4 hours post meals. Non-insulin glucose lowering therapies will be continued throughout the study except for sulfonylureas, which will be stopped if prandial insulin is started at that meal. The initial insulins used in this study will be those prescribed by their normal health care providers and include:
- Basal insulins – glargine (Lantus) and isophane (NPH; Protaphane; Humulin NPH)
- Rapid acting insulins – aspart (NovoRapid), lispro (Humalog) and glulisine (Apidra)
- Premixed insulins – 30% aspart/70% isophane (NovoMix 30), 25% lispro/75% isophane (Humalog Mix 25) and 50% lispro/50% isophane (Humalog Mix 50)
Intervention code [1] 320534 0
Treatment: Devices
Intervention code [2] 320535 0
Lifestyle
Comparator / control treatment
Participants randomized to the control arm will receive standard routine diabetes care from their usual provider. Between scheduled study visits, participants will have the usual ability to contact the clinical team as is routine for all patients. Participants in the control arm will continue self-monitoring blood glucose using conventional finger stick blood glucose testing with a glucometer. The control arm will receive the same personalised insulin titration/management algorithm, but will be reliant on their usual finger prick glucose values. After 10 weeks, a further 2 weeks of blinded CGM glucose values will be collected for the control arm. Throughout the 12-week RCT phase, participants will be contacted by research staff at weeks 2 and 8 to review and if required adjust the insulin titration plan as indicated by the self-management algorithm. Following the primary end-point, those in the control arm will be trained on CGM in the same way the intervention arm was originally trained and use the CGM system for 12 weeks.
Control group
Active

Outcomes
Primary outcome [1] 327491 0
Glycaemic control as measured by percentage of time in range (3.9 – 10mmol/L), by way of CGM data analysis.
Timepoint [1] 327491 0
Baseline, 12 weeks post baseline (primary timepoint), 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [1] 395339 0
Glycaemic control as measured by glycated haemaglobin (HbA1C). HbA1c will be measured from a small whole blood sample by a calibrated point-of-care device (DCA Vantage Analyzer).
Timepoint [1] 395339 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [2] 395340 0
Glycaemic outcomes via CGM data for % CGM time <3.0mmol/L
Timepoint [2] 395340 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [3] 395341 0
Glycaemic outcomes via CGM data for % CGM time <3.9mmol/L
Timepoint [3] 395341 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [4] 395342 0
Glycaemic outcomes via CGM data for % CGM time >10.0mmol/L
Timepoint [4] 395342 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [5] 395343 0
Glycaemic outcomes via CGM data for % CGM time >13.9mmol/L
Timepoint [5] 395343 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [6] 395344 0
Glucose levels during the day (0600-2359 hours), determined from CGM data
Timepoint [6] 395344 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [7] 395345 0
Glucose levels during the night (0000-0559 hours), determined from CGM data.
Timepoint [7] 395345 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [8] 395346 0
Total cholesterol, by laboratory blood test
Timepoint [8] 395346 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [9] 395347 0
High density lipoprotein, by laboratory blood test
Timepoint [9] 395347 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [10] 395348 0
Low Density Lipoprotein, by laboratory blood test
Timepoint [10] 395348 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [11] 395349 0
Triglycerides, by laboratory blood test
Timepoint [11] 395349 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [12] 395351 0
Liver function, measured by alanine aminotransferase, by laboratory blood test
Timepoint [12] 395351 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [13] 395352 0
Liver function, measured by aspartate aminotransferase, by laboratory blood test
Timepoint [13] 395352 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [14] 395353 0
Complete blood count, by laboratory blood test
Timepoint [14] 395353 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [15] 395354 0
Estimated glomerular filtration rate, by laboratory blood test
Timepoint [15] 395354 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [16] 395355 0
Urine albumin creatinine ratio, by laboratory urine test
Timepoint [16] 395355 0
Baseline, 12 weeks post baseline, 24 weeks post baseline, 51 weeks post baseline, 77 weeks post baseline,
Secondary outcome [17] 395356 0
Qualitative interview-based assessment of participant experience using CGM. Semi-structured, one-to-one interviews will be conducted by trained research staff and take approximately 60 minutes.
Timepoint [17] 395356 0
After 24 weeks of CGM use
Secondary outcome [18] 395363 0
Cost-effectiveness analysis, as calculated by cost per percentage point of TIR, using incremental cost-effectiveness analysis. Costs will be assessed by review of study costs and glycaemic outcomes, and are based on the total cost of the trial, excluding costs relating to evaluation of the trial.
Timepoint [18] 395363 0
12 weeks post baseline
Secondary outcome [19] 395364 0
Subjective sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI)
Timepoint [19] 395364 0
Baseline, 12 weeks post baseline, 77 weeks post baseline
Secondary outcome [20] 395365 0
Objective sleep, measured by wearing an actigraphy device continuously for 7 days and 8 nights
Timepoint [20] 395365 0
Baseline, 12 weeks post baseline, 77 weeks post baseline
Secondary outcome [21] 397440 0
The change in sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI)
Timepoint [21] 397440 0
Baseline, 12 weeks post baseline
Secondary outcome [22] 397441 0
The change in sleep quality, as measured by wearing of a wrist-worn actigraphy motion sensor device for 7 consecutive days and nights.
Timepoint [22] 397441 0
Baseline, 12 weeks post baseline.
Secondary outcome [23] 397442 0
Changes in eating behaviour, as measured by review of a 4-day food diary.
Timepoint [23] 397442 0
Baseline, 12 weeks post baseline

Eligibility
Key inclusion criteria
1. Type 2 diabetes as per ADA classification
2. HbA1c greater than 8.0%
3. Minimum daily insulin requirement of greater than or equal to 0.2 units insulin/kg/day, for at least 3 months previous to study enrollment.
4. Aged 16 years and over.
5. Be willing and able to conform to the study protocol
Minimum age
16 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. History of Type 1 diabetes
2. History of other types of diabetes such as MODY, secondary pancreatic diabetes, diabetes due to endocrinopathies
3. Has had a hospital admission for hyperglycaemia in last 6 months
4. Use of systemic corticosteroids for more than 14 days, or repeated pharmacologic systemic courses of corticosteroids
5. Recurrent or chronic systemic infections that in the view of the investigator would significantly impact on glycaemia.
6. Major cardiovascular event (including or not limited to MI, CVA, CABG, PTCA) or major surgery in last 3 months
7. Active malignancy requiring ongoing treatment
8. Previous or planned bariatric surgery.
9. Pregnancy
10. Any other reason that investigator feels may not be in best interest of patient to participate.

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)
Allocation will be done by a biostatistician blinded to allocation arm and will use non-informative group codes until all planned analyses are completed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The study statistician will prepare a computer-generated randomisation list with an allocation ratio of 1:1 and permutated blocks of random size. The randomisation list will be stratified by;
1. Use of metformin (Yes/No)
2. Use of SGLTi or GLP agonist (Yes/No)
The randomisation list will be loaded into the REDCap (Research Data Capture) database by the study statistician immediately prior to moving the project to production status. Once the project is moved to production, the randomisation list is locked and becomes unmodifiable and inaccessible to the study team preserving allocation concealment. The study statistician will have no contact with potential participants or be able to influence enrolment in any way.
Participants who give consent for participation, and fulfil the eligibility criteria, will be enrolled in the study and given a unique study identifier. After stratification variables have been entered into REDCap, research staff with authorisation to randomise participants may click the ‘randomise’ button, which will assign the treatment to the study number according to the randomisation list and lock the fields containing the treatment group and stratification variables.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Our inclusion criteria predicts a population that are likely to have an estimate time in range (TIR) of 56% +/- 20%. To detect a difference to a mean improvement of 14% TIR (to the target TIR of 70% set by international guidelines), at 80% power and a of 0.05, 33 participants are required in each arm. Sample size has been inflated to 40 participants in each arm to account for possible loss-to-follow-up. This power calculation is a conservative estimate, and we are likely to be able to detect a smaller difference. The mean between-group difference in TIR at 12 weeks will be estimated with 95% confidence intervals using analysis of covariance, a general linear model that adjusts for TIR at baseline.

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
12/07/2021
Actual
16/09/2021
Date of last participant enrolment
Anticipated
Actual
12/10/2022
Date of last data collection
Anticipated
30/04/2024
Actual
Sample size
Target
80
Accrual to date
Final
71
Recruitment outside Australia
Country [1] 23748 0
New Zealand
State/province [1] 23748 0
Waikato
Country [2] 23749 0
New Zealand
State/province [2] 23749 0
Canterbury
Country [3] 23750 0
New Zealand
State/province [3] 23750 0
Otago

Funding & Sponsors
Funding source category [1] 308575 0
Commercial sector/Industry
Name [1] 308575 0
DexCom, Inc.
Country [1] 308575 0
United States of America
Primary sponsor type
University
Name
University of Otago
Address
362 Leith Street, North Dunedin, Dunedin 9016
Country
New Zealand
Secondary sponsor category [1] 309651 0
None
Name [1] 309651 0
Address [1] 309651 0
Country [1] 309651 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 308517 0
Central Health and Disability Ethics Committee
Ethics committee address [1] 308517 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington 6011
Ethics committee country [1] 308517 0
New Zealand
Date submitted for ethics approval [1] 308517 0
03/03/2021
Approval date [1] 308517 0
09/04/2021
Ethics approval number [1] 308517 0
21/CEN/75

Summary
Brief summary
Improving glycaemic control is a key target to reduce complications in individuals with type 2 diabetes (T2D) but remains a significant challenge. Continuous glucose monitoring (CGM) is well established in type 1 diabetes to improve health outcomes and reduce disease burden. However, data in T2D is limited. Further, there is a lack of contemporary data using modern CGM, which is more accurate, and does not require capillary glucose calibration. Therefore, modern real-time CGM has a great potential to be utilized by people with T2D and improve glycaemic outcomes and reduce long-term complications and the health economic burden this disease has. This multi-site, 12-week randomized controlled study is followed by a 12-week continuation phase where those initially randomized to routine care cross over into the CGM intervention. The study will enrol 80 participants, aged 16 years and over. Baseline data will be collected from eligible subjects. After a run-in period of 14 days using a blinded Dexcom G6 CGM system to collect baseline glycaemic values, participants will be randomized to continue usual capillary glucose monitoring, or to Dexcom G6 CGM. All participants will receive the same diabetes management schedule to adjust insulin titration based on their glucose levels. After 10 weeks, a further 2 weeks of CGM glucose values will be collected (blinded for the control group) to explore the effect of initiating continuous glucose monitoring in adults with T2D on glycaemia as measured by the primary outcome time in target glucose range (3.9 – 10mmol/L).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 110982 0
Dr Martin de Bock
Address 110982 0
Department of Paediatrics
University of Otago
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 110982 0
New Zealand
Phone 110982 0
+64 3 372 6763
Fax 110982 0
Email 110982 0
martin.debock@otago.ac.nz
Contact person for public queries
Name 110983 0
Dr Martin de Bock
Address 110983 0
Department of Paediatrics
University of Otago
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 110983 0
New Zealand
Phone 110983 0
+64 3 372 6763
Fax 110983 0
Email 110983 0
martin.debock@otago.ac.nz
Contact person for scientific queries
Name 110984 0
Dr Martin de Bock
Address 110984 0
Department of Paediatrics
University of Otago
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 110984 0
New Zealand
Phone 110984 0
+64 3 372 6763
Fax 110984 0
Email 110984 0
martin.debock@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
De-identified data related to the primary and secondary outcomes
When will data be available (start and end dates)?
Data will be available prior to submitting the first manuscript for publication (approximately April 2022) through 10 years (approximately April 2032).
Available to whom?
Those involved in the peer review process for publication in a scientific journal, upon request.
Available for what types of analyses?
Those analyses performed to report the study findings.
How or where can data be obtained?
By emailing the lead investigator, Dr Martin de Bock, martin.debock@otago.ac.nz


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
11881Informed consent form    381981-(Uploaded-08-12-2021-08-32-27)-Study-related document.pdf
11882Ethical approval    381981-(Uploaded-02-06-2021-11-15-37)-Study-related document.pdf



Results publications and other study-related documents

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

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseStudy protocol: glycaemic outcomes in people with type 2 diabetes initiating continuous glucose monitoring: the 2GO-CGM study.2023https://dx.doi.org/10.1007/s40200-023-01244-y
N.B. These documents automatically identified may not have been verified by the study sponsor.