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Trial registered on ANZCTR


Registration number
ACTRN12618001285246
Ethics application status
Approved
Date submitted
25/07/2018
Date registered
31/07/2018
Date last updated
16/04/2020
Date data sharing statement initially provided
26/04/2019
Date results information initially provided
26/04/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Is there a difference when whole grains are eaten whole vs. milled on the blood glucose control of people with type 2 diabetes?
Scientific title
Role of wholegrain structure in the blood glucose control of people with type 2 diabetes as measured over two weeks by continuous glucose monitoring systems.
Secondary ID [1] 295655 0
None
Universal Trial Number (UTN)
U1111-1218-0678
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
The blood glucose control of people with type 2 diabetes 308994 0
Condition category
Condition code
Metabolic and Endocrine 307895 307895 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A two week exposure where wholegrain foods will be provided to participants, where the whole grains are largely intact, which is to say minimally processed. Examples are whole oats, a wholegrain bread with intact grains, and brown rice. Participants completed a pre study four-day dietary record (4DDR) to measure the number of grain serves consumed per day, and were asked to continue consuming that amount from the foods we provided. Adherence with this guideline will be monitored for the two weeks of the intervention with a daily check list, and with a four day diet record during each two-week exposure. There is a two-week wash out period between the interventions.

Blood glucose control will be measured with a continuous glucose monitoring system for the two-week intervention. Participants will receive instructions of how to maintain the device inline with manufacturer recommendations. Previous research by this research group on 41 participants over two interventions did not result in any adverse events due to the use of these devices.
Intervention code [1] 301974 0
Lifestyle
Comparator / control treatment
A two week exposure where wholegrain foods will be provided to participants, where the whole grains are milled or ground down. Examples are instant oats, a wholegrain bread with finely milled flour, and an extruded pasta made with brown rice. Participants completed a pre study 4DDR to measure the number of grain serves consumed per day, and were asked to continue consuming that amount from the foods we provided. Adherence with this guideline will be monitored for the two weeks of the intervention with a daily check list, and with a three day diet record during each two-week exposure. There is a two-week wash out period between the interventions.
Control group
Active

Outcomes
Primary outcome [1] 306867 0
Blood glucose control as measured by: fasting blood glucose, mean blood glucose, postprandial blood glucose, time spent over 8mmol/L, and measures of glycaemic variability.
Timepoint [1] 306867 0
Primary outcome data are obtained from a continuous glucose monitoring system worn for the two weeks of each intervention.
Secondary outcome [1] 349982 0
Palatability of the provided foods will be measured by visual analogue scales (10cm).
Timepoint [1] 349982 0
Collected during each two week intervention on a three day food diary of two week days and one weekend day. These days will occur in the second week of each intervention where the days are specified inline with a computer generated randomisation protocol.
Secondary outcome [2] 349983 0
Change in circulating total cholesterol.
Timepoint [2] 349983 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [3] 349984 0
Difference in dental plaque on teeth between interventions. This is measured by scoring participants mouths after they have chewed a vegetable dye tablet that stains acid producing plaque. Six indicator teeth are scored from 0 (no plaque) to 3 (more than 2/3 of the teeth surface covered).
Timepoint [3] 349984 0
Measured pre and post each intervention.
Secondary outcome [4] 349990 0
Change in body weight (kg).
Timepoint [4] 349990 0
Measured pre and post each intervention.
Secondary outcome [5] 350015 0
Small organic molecule profile of exhaled breath during carbohydrate digestion as measured by mass spectroscopy.
Timepoint [5] 350015 0
We will measure the exhaled gas profile of participants pre and post each intervention. Participants are required to breathe three normal breaths near a sensor.
Secondary outcome [6] 350090 0
Participant satiety due to the provided foods will be measured by visual analogue scales (10cm) throughout the days they complete their three day food diary.
Timepoint [6] 350090 0
Collected during each two week intervention on a three day food diary of two week days and one weekend day. These days will occur in the second week of each intervention where the days are specified inline with a computer generated randomisation protocol.
Secondary outcome [7] 350091 0
Change in circulating LDL cholesterol.
Timepoint [7] 350091 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [8] 350092 0
Change in circulating HDL cholesterol.
Timepoint [8] 350092 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [9] 350093 0
Change in circulating triglycerides.
Timepoint [9] 350093 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [10] 350094 0
Change in circulating C-reactive protein.
Timepoint [10] 350094 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [11] 350095 0
Change in body mass index (BMI).
Timepoint [11] 350095 0
Measured pre and post each intervention.
Secondary outcome [12] 350096 0
Change in fatmass via bioelectrical impedance.
Timepoint [12] 350096 0
Measured pre and post each intervention.
Secondary outcome [13] 350097 0
Change in circulating tumour necrosis factor alpha (TNF-a).
Timepoint [13] 350097 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [14] 350098 0
Change in circulating alkylresorcinols.
Timepoint [14] 350098 0
A fasted venous blood sample taken at the start and end of each two week intervention.
Secondary outcome [15] 350099 0
Change in circulating Interleukins as a marker of systemic inflammation.
Timepoint [15] 350099 0
A fasted venous blood sample taken at the start and end of each two week intervention.

Eligibility
Key inclusion criteria
Diagnosed with type 2 diabetes.
Have not changed prescribed medicine dose or type in the last three months
Willing to comply with study requirements of consuming whole grains each day.
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
pregnant or lactating.

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)
Staff administering the study will not be able to access the sequentially numbered, opaque, sealed envelopes that state the order of interventions until after a participant has provided written informed consent and is ready to start an intervention.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer based randomisation process.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Randomisation process will be balanced between the two interventions.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
The sample size estimate was based on a power calculation with an alpha of 0.05 and power of 0.80 to detect within-group differences in primary outcome variable, a clinically relevant 20 % difference in postprandial glycaemia as measured by CGM. From this calculation we required 28 participants to complete both interventions,

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
31/08/2018
Actual
8/10/2018
Date of last participant enrolment
Anticipated
1/04/2019
Actual
1/04/2019
Date of last data collection
Anticipated
18/05/2019
Actual
18/05/2019
Sample size
Target
28
Accrual to date
Final
28
Recruitment outside Australia
Country [1] 10681 0
New Zealand
State/province [1] 10681 0
Otago

Funding & Sponsors
Funding source category [1] 300238 0
University
Name [1] 300238 0
Department of Medicine, University of Otago
Country [1] 300238 0
New Zealand
Funding source category [2] 302593 0
Charities/Societies/Foundations
Name [2] 302593 0
Laurenson Award
Country [2] 302593 0
New Zealand
Funding source category [3] 305474 0
University
Name [3] 305474 0
Riddet Institute
Country [3] 305474 0
New Zealand
Primary sponsor type
University
Name
University of Otago
Address
PO BOX 56
Dunedin 9010 Otago
Country
New Zealand
Secondary sponsor category [1] 299657 0
None
Name [1] 299657 0
Address [1] 299657 0
Country [1] 299657 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301061 0
Health and Disability Ethics Committees
Ethics committee address [1] 301061 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 301061 0
New Zealand
Date submitted for ethics approval [1] 301061 0
03/08/2018
Approval date [1] 301061 0
03/09/2018
Ethics approval number [1] 301061 0

Summary
Brief summary
Last year we measured the difference in acute blood glucose response due to food where whole grains were either intact, or ground down (ACTRN12617000328370). The differences we observed in blood glucose from these meal responses warrants further investigation, to see if the structural integrity of whole grains may play a role in the longer-term blood glucose control of people with type 2 diabetes.

This new trial therefore looks at blood glucose control in two, two-week interventions. We would like the same people to do both interventions, with a two-week break in between the interventions. In one intervention, we will provide participants with whole grain products that are largely intact (whole oats, bread with whole grains baked in, and brown rice) and ask them to replace their grain servings each day with the foods we provide. In the other intervention we will provide whole grain products that have been milled (instant oats, wholemeal bread, pasta made from brown rice) and ask them to replace their grain servings each day with the foods we provide. Each participant will be randomised to the order they do the interventions in. We would like 28 or more participants to complete both interventions. During each intervention participant's blood glucose control will be measured with continuous blood glucose monitors. We will primarily compare participants blood glucose control with these devices between interventions, but we will also consider possible differences in participant satiety, cholesterol and other blood markers, the level of acid forming plaque on their teeth, and measures of body weight and body fatness.

Our hypothesis is that the structural integrity of the wholegrain is a necessary parameter of why whole grains have been identified as beneficial in both prospective and intervention studies. Removing the structural integrity of whole grains therefore, will reduce the beneficial response. We are particularly interested in blood glucose control, but will also measure blood lipids and inflammation to see if the structural integrity of whole grains might also influence these other cardiometabolic markers.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 41734 0
Dr Andrew Reynolds
Address 41734 0
Department of Medicine
University of Otago
PO Box 56
Dunedin 9010 Otago
Country 41734 0
New Zealand
Phone 41734 0
+64279565826
Fax 41734 0
Email 41734 0
andrew.reynolds@otago.ac.nz
Contact person for public queries
Name 41735 0
Dr Andrew Reynolds
Address 41735 0
Department of Medicine
University of Otago
PO Box 56
Dunedin 9010 Otago
Country 41735 0
New Zealand
Phone 41735 0
+64279565826
Fax 41735 0
Email 41735 0
andrew.reynolds@otago.ac.nz
Contact person for scientific queries
Name 41736 0
Dr Andrew Reynolds
Address 41736 0
Department of Medicine
University of Otago
PO Box 56
Dunedin 9010 Otago
Country 41736 0
New Zealand
Phone 41736 0
+64279565826
Fax 41736 0
Email 41736 0
andrew.reynolds@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
No potentially identifiable data - such as individual patient data - will be released.


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.