Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12620001225909
Ethics application status
Approved
Date submitted
14/10/2020
Date registered
17/11/2020
Date last updated
17/11/2020
Date data sharing statement initially provided
17/11/2020
Type of registration
Retrospectively registered

Titles & IDs
Public title
Glycaemic suppressing effect of kiwifruit – a mechanistic study.
Scientific title
Glycaemic suppressing effect of kiwifruit – a mechanistic study. A randomised, repeated measures, human intervention study
Secondary ID [1] 302515 0
Nil known
Universal Trial Number (UTN)
U1111-1256-2586
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetes 319385 0
Metabolic disorder 319386 0
Condition category
Condition code
Metabolic and Endocrine 317349 317349 0 0
Diabetes
Metabolic and Endocrine 317350 317350 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. Weet-Bix™ + sugars in 2 kiwifruit.
2. Weet-Bix™ + 2 whole kiwifruit
3. Weet-Bix™ + 2 whole kiwifruit neutralised
4. Weet-Bix™ + juice of 2 kiwifruit
5. Weet-Bix™ + 2 kiwifruit sugars + kiwifruit organic acids


13C-labelled sodium acetate (100 mg) will be added to the test meal just before consumption (details on the safety of 13C-labelled sodium acetate is stated below).

An additional 200 ml of water will 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. They may continue work, if practical to do so, at the testing location. Once each subject is relaxed and comfortable (approximately 15-20 minutes after arrival), 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.
The duration of each testing session be 3 hours and 45 minutes.
The participants will be checked off for session attendance.
The participants will be under direction observation from the time they come to the clinic till they finish (about 3.45 hours)
The duration of the washout between each testing session will be 48 hours
Intervention code [1] 318810 0
Prevention
Intervention code [2] 318811 0
Lifestyle
Comparator / control treatment
Control - Weet-Bix + 2 whole kiwifruit.

All results will be compared with the results obtained for Weet-Bix + 2 whole kiwifruit
Control group
Active

Outcomes
Primary outcome [1] 325401 0
Blood glucose as assessed by finger-prick blood test
Timepoint [1] 325401 0
Blood glucose testing will be timed from the start of food consumption by finger prick sampling of capillary blood at 15 min intervals in the first hour and then at 30 min intervals until 180 min has elapsed. Samples will be collected at 0 (baseline x 2), 15, 30, 45, 60, 90, 120, 150 and 180 minutes. The blood glucose will be measured immediately using a HemoCue® blood glucose meter
Secondary outcome [1] 387784 0
Measure changes in insulin
Timepoint [1] 387784 0
Blood sampling will be timed from the start of food consumption by finger prick sampling of capillary blood at 15 min intervals in the first hour and then at 30 min intervals until 180 min has elapsed. Samples will be collected at 0 (baseline x 2), 15, 30, 45, 60, 90, 120, 150 and 180 minutes.
Capillary blood sample will be drawn into a Z gel serum Microvette® microtube designed for capillary blood collection, centrifuged and stored at -80°C for later analysis
Secondary outcome [2] 387785 0
Gastric emptying as assessed by exhaled breath analysis
Timepoint [2] 387785 0
Breath samples will be collected by blowing gently into a 10ml Exetainer with a drinking straw and replacing the cap just before the end of exhalation. Breath samples will be collected at baseline (time = zero minutes) and every 15 min postprandially until 3 hours. Breath samples will be analysed using isotope ratio mass spectrometry.
Secondary outcome [3] 387786 0
Satiety will also be measured using 'Visual Analogue Scale'
Timepoint [3] 387786 0
Time: 0, 15, 30, 45, 60, 90, 120, 150 and 180 minutes post-food consumption.
Secondary outcome [4] 388932 0
Measure changes increatin hormone (gastric inhibitory peptide (GIP)
Timepoint [4] 388932 0
Blood sampling will be timed from the start of food consumption by finger prick sampling of capillary blood at 15 min intervals in the first hour and then at 30 min intervals until 180 min has elapsed. Samples will be collected at 0 (baseline x 2), 15, 30, 45, 60, 90, 120, 150 and 180 minutes.
Capillary blood sample will be drawn into a Z gel serum Microvette® microtube designed for capillary blood collection, centrifuged and stored at -80°C for later analysis

Eligibility
Key inclusion criteria
• Age: Aged between 18 and 40.
• Sex: Male or female.
• Glucose tolerance: No history of diabetes or evidence of glucose intolerance in a preliminary screening test.
• 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
40 Years
Sex
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 (less than or equal to 6.0 mmol/L fasting glucose, International Diabetes Federation recommendation) and HbA1c greater than 40 mmol/mol.
• Non-fasting: Having consumed anything apart from water in the twelve hours prior to the test.
• Allergic or intolerant kiwifruit or wheat.
• Pregnant or breastfeeding.
• Long term chronic illnesses requiring treatment, such as cancer and cardiovascular disease.
• Gut conditions or drugs effecting gut transit time, such as irritable bowel syndrome, peptic ulcers and laxatives.

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.
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=10) 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 incremental area under the curve for blood glucose response, insulin and the incretin hormones, rate of gastric emptying and satiety by comparison of treatments. A registered statistician at Plant and Food Research will conduct the statistical analysis.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
5/11/2020
Date of last participant enrolment
Anticipated
27/11/2020
Actual
Date of last data collection
Anticipated
29/01/2021
Actual
Sample size
Target
10
Accrual to date
7
Final
Recruitment outside Australia
Country [1] 23059 0
New Zealand
State/province [1] 23059 0
Manawatu

Funding & Sponsors
Funding source category [1] 306954 0
Government body
Name [1] 306954 0
The New Zealand Institute for Plant and Food Research
Country [1] 306954 0
New Zealand
Primary sponsor type
Government body
Name
The New Zealand Institute for Plant and Food Research
Address
Batchelar Road,
Food Science Centre,
Palmerston North, 4442
Country
New Zealand
Secondary sponsor category [1] 307512 0
None
Name [1] 307512 0
None
Address [1] 307512 0
None
Country [1] 307512 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 307091 0
The Central Health and Disability Ethics Committee
Ethics committee address [1] 307091 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 307091 0
New Zealand
Date submitted for ethics approval [1] 307091 0
07/09/2020
Approval date [1] 307091 0
19/10/2020
Ethics approval number [1] 307091 0
20/CEN/208

Summary
Brief summary
Kiwifruit has both, viscous fibre and organic acids. Therefore this trial is to study the effect of kiwifruit properties such as organic acids and fibre on blood glucose response. This trial is a pilot study to set up the method to measure gastric emptying as well as to improve our understanding of the possible mechanism involved in glycaemic lowering effect of kiwifruit.
Trial website
Trial related presentations / publications
Public notes
Blood sampling
Blood glucose testing will be timed from the start of food consumption by finger prick sampling of capillary blood at 15 min intervals in the first hour and then at 30 min intervals until 180 min has elapsed. Samples will be collected at 0 (baseline x 2), 15, 30, 45, 60, 90, 120, 150 and 180 minutes. Two analyses will be made from each blood sample: blood glucose will be measured immediately using a HemoCue® blood glucose meter, while the remaining capillary blood sample will be drawn into a Z gel serum Microvette® microtube designed for capillary blood collection, centrifuged and stored at -80°C for later analysis of insulin and incretin hormone (gastric inhibitory peptide). At 0, 15, 60, 120 and 180 min appetite will be assessed using a questionnaire containing recommended visual analogue scales for self-reported appetite in healthy adults (Charlot and Chapelot 2013).

Breath sampling:
Sodium salt of 1-[13C] acetate will be used to measure gastric emptying as acetate is hydrophilic, poorly absorbed in the stomach and rapidly metabolized after absorption. Sodium [1-13C] acetate is considered a reliable and valid method for identifying changes in gastric emptying of semisolids (Braden et al. 1995). Breath samples will be collected by blowing gently into a 10ml Exetainer (Labco, Buckinghamshire, UK) with a drinking straw and replacing the cap just before the end of exhalation. Breath samples will be collected at baseline and every 15 min postprandially until 3 hours. Breath samples will be analysed using isotope ratio mass spectrometry.

Safety of sodium acetate:
13-C sodium acetate is not available in ‘food grade’ but is available in a pyrogen and microbe tested form which is usually accepted as safe for human consumption. https://shop.isotope.com/productdetails.aspx?itemno=CLM-156-CTM

Details on the safety of 13C-labelled sodium acetate is stated below:
o Sodium acetate may be added to food as a seasoning such as to give potato chips a salt and vinegar flavor (https://en.wikipedia.org/wiki/Sodium_acetate)
o It is a very common food constituent in the form of acetic acid (vinegar). It can be found in 5-10% in vinegar.
o It is a natural part of normal intermediatory metabolism in humans.
o 13C is a stable, non-radioactive carbon isotope, and will have no detectable effects in the body, and is used solely as a tracer.

Contacts
Principal investigator
Name 105998 0
Dr John Monro
Address 105998 0
Plant and Food Research
Food Industry Science Centre
Private Bag 11600
Palmerston North 4442
Country 105998 0
New Zealand
Phone 105998 0
+64 63556137
Fax 105998 0
Email 105998 0
john.monro@plantandfood.co.nz
Contact person for public queries
Name 105999 0
Dr John Monro
Address 105999 0
Plant and Food Research
Food Industry Science Centre
Private Bag 11600
Palmerston North 4442
Country 105999 0
New Zealand
Phone 105999 0
+64 63556137
Fax 105999 0
Email 105999 0
john.monro@plantandfood.co.nz
Contact person for scientific queries
Name 106000 0
Dr John Monro
Address 106000 0
Plant and Food Research
Food Industry Science Centre
Private Bag 11600
Palmerston North 4442
Country 106000 0
New Zealand
Phone 106000 0
+64 63556137
Fax 106000 0
Email 106000 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 individual data will be shared. The sum of all the data will be used in analyses and used in publications


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
SourceTitleYear of PublicationDOI
EmbaseDietary Fibre and Organic Acids in Kiwifruit Suppress Glycaemic Response Equally by Delaying Absorption-A Randomised Crossover Human Trial with Parallel Analysis of 13C-Acetate Uptake.2022https://dx.doi.org/10.3390/nu14153189
N.B. These documents automatically identified may not have been verified by the study sponsor.