Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12618000329268
Ethics application status
Approved
Date submitted
21/02/2018
Date registered
6/03/2018
Date last updated
8/02/2019
Date data sharing statement initially provided
8/02/2019
Date results information initially provided
8/02/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Metabolic effects of kiwifruit in people with prediabetes
Scientific title
Effects of longterm kiwifruit consumption on metabolic outcomes in people with prediabetes
Secondary ID [1] 294112 0
Nil known
Universal Trial Number (UTN)
U111112068414
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetes 306705 0
prediabetes 306781 0
Condition category
Condition code
Metabolic and Endocrine 305805 305805 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention:
Participants will be assigned randomly to two groups of 20 subjects each. Both the groups will be asked to continue with their customary diet for fifteen weeks (3 weeks lead in, 12 weeks trial period), but not to consume vitamin supplements. During the lead in period of 3 weeks, all the participants will be asked not to consume any kiwifruit to ensure that the 12 weeks kiwifruit intervention period is a discrete kiwifruit consumption period. The control group will then continue to not consume any kiwifruit for twelve weeks but will be asked to drink 250 mL of provided water 30minutes before their breakfast every day.
The kiwifruit intervention group will be asked to consume two kiwifruit per day for 12 weeks, PREFERABLY 30 MINUTES BEFORE BREAKFAST.
All participants will be asked to attend the Plant & Food Research clinic in the mornings twice, (1) at the beginning of the trial, (2) at the end of the twelve weeks.. The participants will be asked to fast overnight (10-12 hours) and allow 30 mL of venous blood to be withdrawn from their arm by a trained phlebotomist. Finger prick blood will also be taken for fasting blood glucose measurement. Anthropometric measurement including height, weight, blood pressure (automatic sphygmomanometer), waist and hip circumference will be taken during each visit and questions regarding their general wellbeing will be asked. The participants will therefore be expected to attend the clinic two times during the trial and once for screening before the start of the trial.
Participants will also be asked to fill out a seven day food diary two times, covering the seven days leading up to each visit to the clinic.

Blood sampling and analytes:
On the two visits to the clinic during the intervention period, the participants will be asked to provide fasting venous blood samples which will be taken by a trained phlebotomist. Subjects will be seated and once relaxed and comfortable venous blood will be withdrawn from the anterior cubital fossa into Vacutainer™ tubes. Total blood volume collected at each clinic visit will be 30m.

The blood samples will be used to measure the following:
1. HbA1c, insulin, uric acid, creatinine
2. Serum lipids
3. Biomarkers of oxidative stress and inflammation
4. Plasma vitamin C
Capillary finger prick blood sample will be taken for fasting blood glucose measurement.

SunGold kiwifruit will be supplied by the study team.
Intervention code [1] 300393 0
Lifestyle
Intervention code [2] 300446 0
Prevention
Comparator / control treatment
12 weeks of consuming customary diet with no kiwifruit but drinking 250 mL sparkling water 30 minutes before breakfast.
Control group
Active

Outcomes
Primary outcome [1] 304873 0
Change in HbA1c level
Change in HbA1c level in the blood sample. HbA1c between 41-49 mmol/mol is considered as prediabetic range. Therefore, change in HbA1c value would be monitered
Timepoint [1] 304873 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks
Secondary outcome [1] 343431 0
Plasma lipid profile: HDL cholesterol, LDL cholesterol and total lipids.
Timepoint [1] 343431 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks.
Secondary outcome [2] 343781 0
Insulin
Timepoint [2] 343781 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks.
Secondary outcome [3] 343782 0
Uric acid
Timepoint [3] 343782 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks.
Secondary outcome [4] 343783 0
creatinine
Timepoint [4] 343783 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks.
Secondary outcome [5] 343784 0
biomarkers of inflammation eg, c-reactive proteins
Timepoint [5] 343784 0
Blood samples will be taken at the start of the trial and at the end of twelve weeks.

Eligibility
Key inclusion criteria
All participants have pre-diabetes and may or may not be taking medication
Minimum age
18 Years
Maximum age
70 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Intolerance of kiwifruit.
Allergic to kiwifruit
Planned change in diet or medication within the trial period
Any illness or gastrointestinal disorder within the 3 weeks prior to the trial.

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)
Subjects coded by independent person so that identity of subjects unknown to allocator at the time of allocation
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a computer generated randomisation table.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Intervention-free lead-in
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Although this is a pilot study, we will power on a relatively large change in HbA1c of 0.5%. With 80% power and alpha set to 0.05, a sample size of 20 per group is required to detect a difference between groups in HbA1c of 0.5%, given a SD estimate of 0.7% (Incani, M., et al. (2015). "Glycated hemoglobin for the diagnosis of diabetes and prediabetes: Diagnostic impact on obese and lean subjects, and phenotypic characterization." Journal of Diabetes Investigation 6(1): 44-50) and a within-person correlation of 0.6 (from our own data). If we use a within-person correlation of 0.7 we get n=16 per group, which allows for some drop-outs if we have 20 in each group.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
8/03/2018
Actual
8/03/2018
Date of last participant enrolment
Anticipated
29/06/2018
Actual
29/06/2018
Date of last data collection
Anticipated
14/12/2018
Actual
14/12/2018
Sample size
Target
40
Accrual to date
Final
34
Recruitment outside Australia
Country [1] 9610 0
New Zealand
State/province [1] 9610 0
Manawatu

Funding & Sponsors
Funding source category [1] 298747 0
Government body
Name [1] 298747 0
High Value Nutrition Science Challenge, New Zealand Government
Country [1] 298747 0
New Zealand
Primary sponsor type
Government body
Name
New Zealand Institute for Plant and Food Research Limited
Address
New Zealand Institute for Plant and Food Research Limited,
Private Bag 11600,
Palmerston North,
New Zealand
4442
Country
New Zealand
Secondary sponsor category [1] 297924 0
None
Name [1] 297924 0
Address [1] 297924 0
Country [1] 297924 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299686 0
Health and Disability Ethics Committees
Ethics committee address [1] 299686 0
Ministry of Health
133 Molesworth Street
PO Box 5013
Wellington
6011
Ethics committee country [1] 299686 0
New Zealand
Date submitted for ethics approval [1] 299686 0
05/01/2018
Approval date [1] 299686 0
16/02/2018
Ethics approval number [1] 299686 0
18/CEN/2

Summary
Brief summary
Fruit, including kiwifruit, are a valuable component of the human diet because of the wide range of vitamins, minerals and other bioactives that they supply. They are also generally rich in sugars, in particular fruit sugar (fructose) and glucose. Now that glucose intolerance and diabetes are becoming global megatrends there is a growing challenge of how to include fruit in the diets of glucose-intolerant consumers, especially in Asian markets for kiwifruit, in which the incidence of diabetes is expected to reach >400 million by 2030. Glucose may increase exposure to glycaemia and risk of long-term medical complications typical of diabetes. On the other hand, fructose, although less glycaemic, may raise blood triglycerides. Therefore, a concern is that reduced exposure to glycaemia as a result of ingesting fruit in place of more glycaemic foods may be counteracted by unfavourable changes in blood lipids. The challenge is, therefore, multifaceted:
• How to increase fruit intake without adversely increasing exposure to glucose-induced postprandial glycaemia (HbA1c).
• How to do so without unfavourably altering plasma lipids due to an increase in fructose intake,
• How to use whole kiwifruit to gain the protective benefits of fruit bioactives against processes leading to diabetic complications.
The associated research questions are:
1. Can kiwifruit be included in the diet without exacerbating exposure to postprandial glycaemia?
2. Can the fructose-rich sugars in kiwifruit be regularly consumed without plasma lipid changes associated with increased disease risk?
3. Can it be shown that regular consumption of kiwifruit in fact counteracts the systemic biochemical processes through which glycaemia leads to medical complications typical of long-term diabetes, which are believed to be mediated by glycation, inflammation and oxidative stress, and counteracted by fruit bioactives such as phenolics and vitamin C?
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 81294 0
Dr John Monro
Address 81294 0
The New Zealand Institute for Plant and Food Research,
Private Bag 11600,
Palmerston North
4442
Country 81294 0
New Zealand
Phone 81294 0
+6463556137
Fax 81294 0
Email 81294 0
john.monro@plantandfood.co.nz
Contact person for public queries
Name 81295 0
Dr John Monro
Address 81295 0
The New Zealand Institute for Plant and Food Research,
Private Bag 11600,
Palmerston North
4442
Country 81295 0
New Zealand
Phone 81295 0
+6463556137
Fax 81295 0
Email 81295 0
john.monro@plantandfood.co.nz
Contact person for scientific queries
Name 81296 0
Dr John Monro
Address 81296 0
The New Zealand Institute for Plant and Food Research,
Private Bag 11600,
Palmerston North
4442
Country 81296 0
New Zealand
Phone 81296 0
+6463556137
Fax 81296 0
Email 81296 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
Only average values from all participants will be used in the publication


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.