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Trial registered on ANZCTR


Registration number
ACTRN12617000546358
Ethics application status
Approved
Date submitted
21/03/2017
Date registered
18/04/2017
Date last updated
19/03/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Effect of prolonged fasting on blood sugars in overweight/obese volunteers with type 2 diabetes
Scientific title
Effect of prolonged fasting on glycaemia in overweight/obese volunteers with type 2 diabetes
Secondary ID [1] 291458 0
nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetes 302499 0
Condition category
Condition code
Metabolic and Endocrine 302055 302055 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will come to the Human Nutrition Unit (University of Auckland) fasted. This study is of a cross-over design and thus participants will need to come on two separate occasions within a 6-day period.
Day 1 (Human Nutrition Unit): Participants will be given breakfast, lunch, and dinner. Blood glucose, insulin, and free fatty acids will taken after each meal at set time points (up to 180 mins). [Intervention Arm 1]
Day 2 (home): Participants are given breakfast, lunch and dinner to eat at home (same meals as day before). Participants will be monitored via a continuous glucose monitoring system
Day 3: wash-out
Day 4: wash-out
Day 5 (Human Nutrition Unit): Participants will not be given breakfast, but lunch and dinner. Blood glucose, insulin, and free fatty acids will taken after each meal at set time points (up to 180 mins). [Intervention Arm 2]
Day 6 (home): Participants are given breakfast, lunch and dinner to eat at home. Participants will be monitored via a continuous glucose monitoring system

Order of treatment will be determined by randomisation. Each clinic day will be approximately 10 hours. Each participant will wear the continuous glucose monitor for the entire 6-day period.

Breakfast, lunch, and dinner will be given at 0845h, 1245h, 1745h; respectively at HNU. Participants will be asked to consume meals at the same time when they are at work/home.
All meals will be 3MJ, ~55% carbohydrate, ~25% fat, ~15% protein, ~3-5% fibre.

Intervention adherence will be assessed via the CGMS. A log will be provided with the CGMS, to record calibration measurements, food intake, medications, and activity. If outliers are present in the CGMS data (due to poor compliance), the participant may be asked to repeat the intervention.
Intervention code [1] 297509 0
Lifestyle
Comparator / control treatment
The control treatment is that the participants eat breakfast, thus the overnight fast is not prolonged.
Control group
Active

Outcomes
Primary outcome [1] 301473 0
Changes in postprandial blood glucose
Timepoint [1] 301473 0
- Baseline (fasted at the start of each clinic day)
- After each meal (time points will still apply even if participants did not eat breakfast): post-meal time 15 min, time 30 min, time 45 min, time 60 min, time 90 min, time 120 min, time 150 min, time 180 min
- Glucose will also be measured via a continuous glucose monitoring system which will be worn for 6 days
Primary outcome [2] 301474 0
Changes in postprandial insulin, measured via blood analysis
Timepoint [2] 301474 0
- Baseline (fasted at the start of each clinic day)
- After each meal (time points will still apply even if participants did not eat breakfast): post-meal time 15 min, time 30 min, time 45 min, time 60 min, time 90 min, time 120 min, time 150 min, time 180 min
Secondary outcome [1] 332844 0
Changes in postprandial free fatty acids, measured via blood analysis
Timepoint [1] 332844 0
- Baseline (fasted at the start of each clinic day)
- After each meal (time points will still apply even if participants did not eat breakfast): post-meal time 15 min, time 30 min, time 45 min, time 60 min, time 90 min, time 120 min, time 150 min, time 180 min

Eligibility
Key inclusion criteria
Overweight/obese (BMI 28-35kg/m2)
Diagnosed with Type 2 diabetes (diet controlled or on Metformin only)
Aged 40-60 years
Minimum age
40 Years
Maximum age
60 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Diagnosed with type 1 diabetes, or other metabolic disorder
·Sulfonylurea, insulin or other diabetic therapies
Any diagnosed digestive or malabsorptive disorder

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)
Central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by
computer software
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
It is anticipated that 20 participants will be required to complete the intervention, based on the assumptions shown below:

Two treatment, cross-over design
Significance, P<0.05
Power, 90%

(i) Change in blood glucose to be detected as significant, 0.5mmol/L
Within-participant variance in blood glucose, 0.4 mmol/L (SD)
Sample size required, n=16

(ii) Change in blood glucose to be detected as significant, 0.5mmol/L
Within-participant variance in blood glucose, 0.5 mmol/L (SD)
Sample size required, n=24

http://hedwig.mgh.harvard.edu/sample_size/js/js_crossover_quant.html

Recruitment
Recruitment status
Completed
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] 8745 0
New Zealand
State/province [1] 8745 0
Auckland

Funding & Sponsors
Funding source category [1] 295929 0
University
Name [1] 295929 0
University of Auckland School of Biological Sciences
Address [1] 295929 0
University of Auckland School of Biological Sciences
Building 110, Thomas Building
3a Symonds Street
Auckland CBD
Auckland 1010
Country [1] 295929 0
New Zealand
Primary sponsor type
University
Name
University of Auckland School of Biological Sciences
Address
University of Auckland School of Biological Sciences
Building 110, Thomas Building
3a Symonds Street
Auckland CBD
Auckland 1010
Country
New Zealand
Secondary sponsor category [1] 294829 0
None
Name [1] 294829 0
Address [1] 294829 0
Country [1] 294829 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297206 0
Health and Disability Ethics Committee
Ethics committee address [1] 297206 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 297206 0
New Zealand
Date submitted for ethics approval [1] 297206 0
02/03/2017
Approval date [1] 297206 0
10/05/2017
Ethics approval number [1] 297206 0
17/CEN/54

Summary
Brief summary
Hypothesis: Prolonging the overnight fast (i.e. missing the breakfast meal) has negative effects on blood sugars throughout the day
The two intervention arms are:
1. Normal fasting period (i.e. breakfast, lunch and dinner provided)
2. Prolonged fasting period (i.e. breakfast omitted, only lunch and dinner provided)
Both intervention arms comprise 2 days:
Day 1: The participant arrives fasted. A continuous glucose monitor (CGM) is fitted, and an indwelling venous cannula inserted into the forearm. Blood samples are collected at baseline, and throughout a 3h period following each meal. Breakfast, lunch, and dinner will be given at 0845h, 1245h, 1745h; respectively at HNU. At the end of Day 1 the participant returns home with the CGM in situ.
Day 2: Participants consume a standardised breakfast, lunch and dinner at home, and blood glucose is assessed by CGM.
Day 3-4: Wash-out period
Day 5: The participant arrives fasted. A continuous glucose monitor (CGM) is fitted, and an indwelling venous cannula inserted into the forearm. Blood samples are collected at baseline, and throughout a 3h period following each meal. No breakfast will be given; but lunch, and dinner will be given at 1245h, 1745h; respectively at HNU. At the end of Day 5, the participant returns home with the CGM in situ.
Day 6: Participants consume a standardised breakfast, lunch and dinner at home, and blood glucose is assessed by CGM.
The CGM remains in situ and is removed at the end of the 6 day study
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 73338 0
Prof Sally Poppitt
Address 73338 0
University of Auckland Human Nutrition Unit
18 Carrick Place
Mount Eden
Auckland 1024
Country 73338 0
New Zealand
Phone 73338 0
+6496301162
Fax 73338 0
Email 73338 0
s.poppitt@auckland.ac.nz
Contact person for public queries
Name 73339 0
Miss Audrey Tay
Address 73339 0
University of Auckland Human Nutrition Unit
18 Carrick Place
Mount Eden
Auckland 1024
Country 73339 0
New Zealand
Phone 73339 0
+6496301162
Fax 73339 0
Email 73339 0
atay428@aucklanduni.ac.nz
Contact person for scientific queries
Name 73340 0
Prof Sally Poppitt
Address 73340 0
University of Auckland Human Nutrition Unit
18 Carrick Place
Mount Eden
Auckland 1024
Country 73340 0
New Zealand
Phone 73340 0
+6496301162
Fax 73340 0
Email 73340 0
s.poppitt@auckland.ac.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary