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Trial registered on ANZCTR


Registration number
ACTRN12618001826235
Ethics application status
Approved
Date submitted
24/10/2018
Date registered
9/11/2018
Date last updated
9/11/2018
Date data sharing statement initially provided
9/11/2018
Date results information initially provided
9/11/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
A human intervention trial to study the effect of kibbled grain breads on blood glucose concentrations compared with commonly consumed highly glycaemic white bread.
Scientific title
The role of kibbled grains in breads for blood glucose control - A randomised, repeated
measures, human intervention study.
Secondary ID [1] 296402 0
The New Zealand Institute of Plant and Food Research CoRE funding programme Project code: P/224007/01
Universal Trial Number (UTN)
U1111-1220-1812
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetes 310152 0
Metabolic disorders 310153 0
Condition category
Condition code
Metabolic and Endocrine 308903 308903 0 0
Diabetes
Metabolic and Endocrine 308904 308904 0 0
Metabolic disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A randomised repeated measures design will be used in which each subject receives all diets in a random order.
The test foods will be as follows:

1. White bread: 93 g (Reference) plus 100 ml water (Treatment: Chew)
2. Soy-purple wheat kibbled bread: 109 g plus 100 ml water (Treatment: Chew)
3. Purple wheat kibbled bread: 154 g plus 100 ml water (Treatment: Chew)
4. White bread: 93 g (Reference) homogenized with 100 ml water (Treatment: Swallow)
5. Soy-purple wheat kibbled bread: 109 g homogenized with 100 ml water (Treatment: Swallow)
6. Purple wheat kibbled bread: 154 g homogenized with 100 ml water (Treatment: Swallow)
7. White bread: 93 g (Reference) plus 100 ml water (Treatment: Swallow without chewing)
8. Soy-purple wheat kibbled bread: 109 g plus 100 ml water (Treatment: Swallow without chewing)
9. Purple wheat kibbled bread: 154 g plus 100 ml water (Treatment: Swallow without chewing).

An additional 200 ml of water will be consumed with all diets.

Foods given above contain approximately 40 g of available carbohydrate. The exact available carbohydrate content of all diets will be determined by in vitro digestive analysis prior to calculating the results.

The breads will be prepared in the Plant & Food Research, food safe labs. Breads will be baked on every Friday and divided into required portions and frozen until testing so that all subjects are tested with kibbled grain and white breads that have had identical treatment. Respondents will be asked to come for the trial between Mondays to Fridays. The breads will be thawed to room temperature overnight before being served. Participants will be asked to ingest breads 1, 2, 3 and 7, 8, 9 with and without chewing respectively, which will take 6 sessions for the subject. Breads 4. 5, 6 will be thawed to room temperature (overnight), homogenized with 100 ml of water not more than 1 h before testing, and consumed in 3 sessions. The subjects will be given 200 ml of water to be consumed with all diets.

On each test day the volunteers will be seated and asked to remain so for the duration of the test. Once each subject is relaxed and comfortable a baseline blood sugar measurement will be taken in duplicate for that day. Each subject will then be given a test food and instructed to consume the whole amount within a ten-minute period. Blood glucose testing will be by finger prick blood sampling. Samples will be thus be collected at 0 (baseline x 2), 15, 30, 45, 60, 90 and 120 minutes. Blood glucose will be measured immediately using a HemoCue® blood glucose meter. A visual analogue scale will be used to measure appetite over the two hours at 0, 30, 60, 90 and 120 mins. The washout period for this crossover study is 48 hours between each session.

Intervention code [1] 312731 0
Prevention
Intervention code [2] 312732 0
Lifestyle
Comparator / control treatment
White bread (93 g = 40 g of available carbohydrates)

a. White bread: 93 g (Reference) plus 100 ml water (Treatment: Chew)
b. White bread: 93 g (Reference) homogenized with 100 ml water (Treatment: Swallow)
c. White bread: 93 g (Reference) plus 100 ml water (Treatment: Swallow without chewing)
Control group
Active

Outcomes
Primary outcome [1] 307871 0
To determine the glycaemic potency and demonstrate the effect of postprandial blood glucose concentrations of soy-purple wheat kibbled bread, purple wheat kibbled bread and white bread on a 40 g carbohydrate basis.
Timepoint [1] 307871 0
Measure blood glucose concentrations at 0 (baseline x 2), 15, 30, 45, 60, 90 and 120 minutes after a serving of two kibbled grain bread varieties and a white bread reference (equivalent 40 g carbohydrate) in a particular type of treatment. Nine test sessions will be conducted over a period of seven weeks with at least a 48-hour washout between sessions.
Secondary outcome [1] 353187 0
To determine the effect of intact grain structure on the postprandial blood glucose concentrations in response to ingesting bread with or without chewing.
Timepoint [1] 353187 0
Measure blood glucose concentrations at 0 (baseline x 2), 15, 30, 45, 60, 90 and 120 minutes after a serving of two kibbled bread varieties and a white bread reference (equivalent 40 g carbohydrate) in a particular type of treatment. Nine test sessions will be conducted over a period of seven weeks with at least a 48-hour washout between sessions.
Secondary outcome [2] 353188 0
Measure satiety with a visual analogue scale following consumption of two kibbled grain bread varieties: Soy-purple wheat kibbled bread, purple wheat kibbled bread and a white bread reference.
Timepoint [2] 353188 0
A visual analogue scale will be used to measure appetite over the two hours at 0, 30, 60, 90 and 120 mins. Nine test sessions will be conducted over a period of seven weeks with at least a 48-hour washout between sessions.

Eligibility
Key inclusion criteria
• Age: Aged between 18 and 65.
• Sex: Male or female.
• Glucose tolerance: No history of diabetes or evidence of glucose intolerance in a preliminary screening test (glycated haemoglobin below 40 mmol/mol ).
• Gluten and soy tolerance: No history of intolerance towards gluten, soy and bread products.
• BMI: Volunteers have a body mass index between 18 and 35 kg/m2
• Health: Healthy as gauged by self-assessment and result on the General Health Questionnaire.
• Agreement: Subject having given written informed consent to comply with the conditions of the trial.
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
• Glucose intolerance: Any history of diabetes or evidence of glucose intolerance in a preliminary test.
• Gluten and soy intolerance: Any history of intolerance towards gluten, soy and bread products.
• Non-fasting: Having consumed anything apart from water in the twelve hours prior to the test.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Each participant will be assigned an identification number, including those who fail the screening procedure by central randomization by computer.

Participants who pass the screening procedure will be allocated numbers after the recruitment process is finished. Therefore, the recruiter was unaware of the treatment order for each individual at time of recruiting. Each participant receives all treatments in random order rather than being allocated to one group. Randomization of the samples and treatments will be completed by a statistician at Plant & Food Research using a computer.

Allocation Not Concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The order of the diets and treatments for each subject (n=12) will be determined by computer randomisation of numbers
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Groups will be compared in terms of response amplitude, time o baseline and incremental area under the blood glucose response curve by comparison of treatments. A registered statistician at Plant and Foood Research will conduct the statistical analysis.

The participant numbers (n = 12) exceeds the minimum number (n=10) specified by the current ISO method (ISO 26642:2010) for determination of glycaemic index and is typical of studies involving comparisons of foods.

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 20948 0
New Zealand
State/province [1] 20948 0
Manawatu

Funding & Sponsors
Funding source category [1] 301010 0
Government body
Name [1] 301010 0
The New Zealand Institute for Plant & Food Research Limited
Address [1] 301010 0
Private Bag 11600, Palmerston North 4442, New Zealand
Country [1] 301010 0
New Zealand
Primary sponsor type
Government body
Name
The New Zealand Institute for Plant & Food Research Limited
Address
Private Bag 11600, Palmerston North 4442, New Zealand
Country
New Zealand
Secondary sponsor category [1] 300599 0
None
Name [1] 300599 0
Address [1] 300599 0
Country [1] 300599 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301768 0
Northern A Health and Disability Ethics Committee
Ethics committee address [1] 301768 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 301768 0
New Zealand
Date submitted for ethics approval [1] 301768 0
12/09/2018
Approval date [1] 301768 0
17/10/2018
Ethics approval number [1] 301768 0
18/NTA/160

Summary
Brief summary
Kibbled grain breads are likely to have a lower glycaemic effect than white breads because they have a number of features associated with reduced blood glucose response such as dietary fibre, and plant structure that limits starch digestibility.

The aim of the study is to establish the effect of two types of kibbled grain breads on blood glucose relative to the effect of a white bread reference. This study also determines the effect of intact grain structure on the postprandial blood glucose responses to bread with or without chewing. This will give us a measure of the in vivo relative glycaemic potency of the two bread types, which have been selected for possessing low glycaemic potency when estimated using validated in vitro methods.

Standard glycaemic response testing protocols will be used. After an overnight fast, participants will consume a different one of each of nine bread samples delivering 40 g available carbohydrate, on nine occasions, each a week apart. The breads will be: 1) White bread, (2) Soy and purple wheat kibbled grain bread and (3) Purple wheat kibbled grain bread, each in three forms:(1) As normally masticated, (2) swallowed without chewing, and (3) swallowed after homogenizing, giving the 9 samples. A randomised repeated measures design will be used in this study. Blood glucose will be measured by finger prick sampling at 8-time points over a two hour period. Two blood samples will be taken at baseline and single blood samples over the 2 hour postprandial period. Blood glucose concentrations will be measured with a HemoCue® blood glucose meter, and changes from baseline will be plotted against time to obtain blood glucose response curves. These curves will be analysed to obtain information on the area under the curve and the distribution of the area to reveal the glycaemic impact characteristics of the bread samples.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 88034 0
Dr John Monro
Address 88034 0
Plant and Food Research
Food Industry Science Centre
Private Bag 116000
Palmerston North 4474
Country 88034 0
New Zealand
Phone 88034 0
+64 211644660
Fax 88034 0
Email 88034 0
john.monro@plantandfood.co.nz
Contact person for public queries
Name 88035 0
Dr Suman Mishra
Address 88035 0
Plant and Food Research
Food Industry Science Centre
Private Bag 116000
Palmerston North 4474
Country 88035 0
New Zealand
Phone 88035 0
+64 63556215
Fax 88035 0
Email 88035 0
suman.mishra@plantandfood.co.nz
Contact person for scientific queries
Name 88036 0
Dr John Monro
Address 88036 0
Plant and Food Research
Food Industry Science Centre
Private Bag 116000
Palmerston North 4474
Country 88036 0
New Zealand
Phone 88036 0
+64 211644660
Fax 88036 0
Email 88036 0
john.monro@plantandfood.co.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 material that could personally identify the participant will be used in any reports on this study. All information collected in all parts of the study is confidential and will not be available to anyone other than the principal investigator and the co-investigator. The samples and data will be identified by study ID number only and will be stored in a lockable filing cabinet on a security-carded floor.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary