ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12617000510347

Ethics application status

Approved

Date submitted

5/04/2017

Date registered

7/04/2017

Date last updated

11/10/2017

Type of registration

Retrospectively registered

Titles & IDs

Public title

The effect of intermittent energy restriction on the way blood vessels work

Scientific title

The effect of fasting on endothelial function in healthy adults or adults with type 2 diabetes.

Secondary ID [1]

Nil Known

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Cardiovascular Disease

Obesity

Condition category

Condition code

Cardiovascular

Other cardiovascular diseases

Diet and Nutrition

Obesity

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

In a randomized cross-over study including 32 adults men and women an intermittent energy restriction regime asking participants to follow a very low calorie diet (2100kJ for women and 2500kJ for men) for two days per week before returning to their normal eating habits for the other 5 days will be prescribed. This is commonly known as the 5:2 diet. Participants will be asked to attend the Sansom Institute for Health Research Clinical Trials Facility on four separate occasions. Body height (once only), body weight & and blood vessel function (using techniques of applying blood pressure cuffs to you upper arm and thigh and an ultrasound of the artery above your elbow) will be measured as part of an initial screening visit participants will also meet with a dietitian who will assess eligibility for the study & provide information about the diet. Dietary compliance will be measured via weighed food diary (weighing everything you eat) for the duration of each fast day during the trial (8 days). The fasting days are required to be consecutive, and the 5:2 regime is to be followed continuously for 4 weeks. Visit 2 will occur two weeks later and will involve a check in with the dietitian to check dietary compliance. The following week participants will be asked to return for a visit following 2 fast days or 2 ad libitum eating days (this will be discussed in visit 2) for assessment of weight and blood vessel function. Visit 4 they will return for measurements as taken in visit 3 following the reverse dietary condition. The order of assessment for visits 3 and 4 is randomised using an online randomisation generator. Participants will also have their liver size measured via ultrasound at the baseline and last visit of the trial. The study runs for a total of 4 weeks.

Intervention code [1]

Lifestyle

Intervention code [2]

Treatment: Other

Comparator / control treatment

The comparator is testing individuals following 2 ad libitum eating days.

Control group

Active

Outcomes

Primary outcome [1]

Investigate the effect of two fasting days compared to two ad libitum eating days on blood vessel function. Blood vessel function will be assessed by Flow Mediated Dilatation, measured via brachial ultrasound.

Timepoint [1]

Weeks 3 and 4 of the intervention following 2 fast days or 2 ad libitum eating days depending on the randomisation the participant has received.

Secondary outcome [1]

Determine changes in serum lipids.

Timepoint [1]

Weeks 3 and 4 of the intervention following 2 fast days or 2 ad libitum eating days depending on the randomisation the participant has received.

Secondary outcome [2]

Determine changes in plasma glucose.

Timepoint [2]

Weeks 3 and 4 of the intervention following 2 fast days or 2 ad libitum eating days depending on the randomisation the participant has received.

Secondary outcome [3]

Determine Changes in Insulin.

Timepoint [3]

Weeks 3 and 4 of the intervention following 2 fast days or 2 ad libitum eating days depending on the randomisation the participant has received.

Secondary outcome [4]

Determine changes in liver size. Participants will have a very short liver ultrasound (less than 5 minutes) in which two pictures of the liver will be taken. Participants will be placed supping on an ultrasound table with their body tilted 45 degrees to the left in a direction away from the sonographer. The participants skin will be exposed from their waist to their xiphisternum. Measurements will be made from the images later.

Timepoint [4]

Measure liver size at baseline and at week 4 of the trial.

Eligibility

Key inclusion criteria

BMI > 18.5 kg/m
Aged 18 - 75 years
Not pregnant or breast feeding
Participant reports they are healthy or have type 2 diabetes managed by diet alone or stable dose metformin

Minimum age

18 Years

Maximum age

75 Years

Sex

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

Drinking more than 5 standard drinks per day and unable/unwilling to stop
Participant reports they are unwell
Participating in any ongoing dietary studies
Eating out more than once a fortnight and unable/unwilling to stop for the duration of the study

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)

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people assessing the outcomes

Intervention assignment

Crossover

Other design features

Phase

Type of endpoint/s

Statistical methods / analysis

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

Actual

23/03/2017

Date of last participant enrolment

Anticipated

30/06/2017

Actual

19/07/2017

Date of last data collection

Anticipated

31/07/2017

Actual

23/08/2017

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

Funding & Sponsors

Funding source category [1]

University

Name [1]

University of South Australia

Address [1]

GPO Box 2471, Adelaide 5001

Country [1]

Australia

Primary sponsor type

University

Name

University of South Australia

Address

GPO Box 2471, Adelaide 5001

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

University of South Australia

Ethics committee address [1]

GPO Box 2471, Adelaide 5001

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

22/11/2016

Approval date [1]

19/01/2017

Ethics approval number [1]

0000036095

Summary

Brief summary

The vascular endothelium plays an important role in the regulation in several important bodily processes, including arterial tone, thrombosis, and inflammation. Dysfunction in the endothelium can lead to the development of atherosclerotic lesions, a pathophysiological link to acute cardiovascular disorders.   A common condition associated with endothelial dysfunction is obesity.  Current research suggests that the mechanism of obesity-induced endothelial dysfunction may be multifactorial, as excess adipose tissues has been shown to induce several metabolic changes which have the potential to interfere with normal endothelial function. A recent meta-analysis (Joris, P J et al. 2015) of human studies on the effects of weight loss on FMD of the brachial artery reported that weight loss increased FMD vs. control by 3.29%.  It also estimated that each 10kg decrease in body weight increased fasting FMD by 1.11%. Researchers highlighted that effects may depend on subject characteristics, type of weight-loss treatment, and dietary composition.  Within the studies included in the meta-analysis, increases in FMD were larger in the higher weight-loss group when subjects consumed low-fat diets compared with low-carbohydrate diets. What has not been investigated however, in this meta-analysis or indeed in any RCT to date, is whether the impact of changed dietary composition (and resulting hypocaloric conditions) through intermittent energy restriction results in a change in FMD. Accordingly, the current study is designed to investigate the effect of intermittent energy restriction on endothelial function, relative to habitual intakes.  This research will add value to the scientific field by adding to the existing literature targeting intermittent energy restriction and its potential health benefits. primary aim of this study is to investigate the effect of two fasting days compared to two ad libitum eating days on blood vessel function. Secondary aim is to determine changes in, serum lipids, plasma glucose and insulin. We hypothesize that individuals will have similar endothelial function following two fasting days compared to two ad libitum eating days.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Mrs Michelle Headland

Address

University of South Australia
GPO Box 2471, Adelaide 5001

Country

Australia

Phone

+61 438 7020 99

Fax

michelle.headland@mymail.unisa.edu.au

Contact person for public queries

Name

Jennifer Keogh

Address

University of South Australia
GPO Box 2471, Adelaide 5001

Country

Australia

Phone

+61 8 830 22579

Fax

jennifer.keogh@unisa.edu.au

Contact person for scientific queries

Name

Jennifer Keogh

Address

University of South Australia
GPO Box 2471, Adelaide 5001

Country

Australia

Phone

+61 8 830 22579

Fax

jennifer.keogh@unisa.edu.au

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

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Documents added automatically

No additional documents have been identified.

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