Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12625000908437p
Ethics application status
Not yet submitted
Date submitted
6/08/2025
Date registered
21/08/2025
Date last updated
21/08/2025
Date data sharing statement initially provided
21/08/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
The impact of time-restricted eating in adults with obstructive sleep apnoea
Scientific title
The impact of time-restricted eating on cardio-metabolic outcomes in adults with obstructive sleep apnoea - a pilot randomised controlled trial
Secondary ID [1] 315067 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obstructive sleep apnoea 338448 0
Condition category
Condition code
Respiratory 334744 334744 0 0
Sleep apnoea

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Randomised controlled trial (pilot trial) comparing the effectiveness of Time Restricted Eating (TRE) in conjunction with Continuous Positive Airway Pressure treatment (CPAP+TRE) versus CPAP treatment alone (CPAP usual care). Implementation over 12 weeks with 1 week for baseline measures.

CPAP + TRE: TRE is a dietary approach that involves limiting food intake to a specific window of time each day. It's a form of intermittent fasting where the focus is on when you eat, rather than what you eat. TRE restricts calorie intake within a defined period, allowing the body to fast for the remaining hours of the day.
Patients will use CPAP for 12 weeks set up in person by a sleep scientist at a hospital clinic. Participants will be instructed by a research assistant to limit food intake to a 10 hours window for a minimum of 5 days per week, with no food consumption beyond 8pm. Water, zero calorie drinks, and prescribed medications will be allowed outside of the TRE window. Adherence for TRE is expected to be 70% to allow for lifestyle flexibility. CPAP adherence is monitored through data download from the CPAP machine itself, which tracks usage hours, mask leaks, and the pressure setting.

CPAP (usual care): Patients will use CPAP set up in person by a sleep scientist at a hospital clinic for 12 weeks. Participants in this arm will be instructed by a research assistant to eat ad libitum with no restrictions on timing and frequency.

All participants will attend 3 visits and undertake multiple assessments relating to sleep, cardiovascular health, and medical information. Measures with include a venous blood draw by a physician.
Each participant will be asked to complete a 3-consecutive day meal timing diary at baseline, week 2, week 7, and week 12, recording the clock time of the first and last meal each day. Diary may be hard copy or via SMS as per patient preference. Adherence to TRE in the intervention group will be calculated as the number of days with a <10-h eating window/7 days of the week, expressed as a percentage. Weekly SMS reminders will be sent to participants in both groups to encourage CPAP adherence and diary logging.

A food and drink diary will also be completed by all participants for 3 days (including 1 weekend day) prior to the study, during week 2 and week 7 of the intervention, and during the final week of the study to estimate daily caloric intake.
Intervention code [1] 331678 0
Lifestyle
Intervention code [2] 331748 0
Treatment: Other
Comparator / control treatment
CPAP (usual care): Patients will use CPAP for 12 weeks. Participants in this arm will be instructed to eat ad libitum with no restrictions on timing and frequency.
CPAP involves using a machine to deliver a continuous flow of pressurized air through a mask to keep the airway open during sleep, used to treat obstructive sleep apnea (OSA). The pressurized air prevents the airway from collapsing, allowing for uninterrupted breathing.
Control group
Active

Outcomes
Primary outcome [1] 342397 0
Body weight in kg
Timepoint [1] 342397 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [1] 450676 0
Fasting blood glucose
Timepoint [1] 450676 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [2] 450677 0
Fasting lipids
Timepoint [2] 450677 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [3] 450678 0
Blood pressure
Timepoint [3] 450678 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [4] 450679 0
Sleep outcomes
Timepoint [4] 450679 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [5] 450680 0
Dietary intake
Timepoint [5] 450680 0
Baseline, 2 weeks, 7 weeks, 12 weeks post-intervention commencement,
Secondary outcome [6] 450681 0
3-consecutive day meal timing
Timepoint [6] 450681 0
Baseline, 2 weeks, 7 weeks, 12 weeks post-intervention commencement,
Secondary outcome [7] 450682 0
Sleepiness
Timepoint [7] 450682 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [8] 450683 0
Sleep Quality
Timepoint [8] 450683 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [9] 450685 0
Activity levels
Timepoint [9] 450685 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [10] 450686 0
Waist and hip circumference
Timepoint [10] 450686 0
Baseline, 12 weeks post-intervention commencement,
Secondary outcome [11] 450687 0
CPAP usage
Timepoint [11] 450687 0
12 weeks post-intervention commencement,
Secondary outcome [12] 450692 0
Body fat, Visceral fat mass and muscle mass assessed as a composite outcome
Timepoint [12] 450692 0
Baseline, 12 weeks post-intervention commencement,

Eligibility
Key inclusion criteria
Body Mass Index 28-40 kg/m2,
Newly diagnosed with moderate to severe Obstructive Sleep Apnoea (AHI>15events/h) and prescribed CPAP,
With a reported habitual eating window of at least 12 hours.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
- Within healthy weight range
- Pregnancy / breastfeeding
- Had previous weight loss surgery
- history of eating disorders
- using anti-obesity medications
- diagnosis of T1D and insulin-dependent T2D, or any medication that could interfere with weight loss (on a case by case basis),
- renal failure, heart failure, recent MI/stroke (within previous 6months),
- routine shiftwork,
- active psychiatric condition or intellectual disability that would prevent them from following the study protocol.
- Unwilling or unable to provide informed consent

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)
Allocation concealment will be carried out via central randomisation by computer using a secure computer-generated random number sequence.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation to be performed by adaptive methods, in particular minimisation stratified by gender (male, female) and age.
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
22/09/2025
Actual
Date of last participant enrolment
Anticipated
29/06/2026
Actual
Date of last data collection
Anticipated
28/09/2026
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 28292 0
Eastern Health - Box Hill
Recruitment postcode(s) [1] 44504 0
3128 - Box Hill

Funding & Sponsors
Funding source category [1] 319635 0
Charities/Societies/Foundations
Name [1] 319635 0
Eastern Health Foundation
Country [1] 319635 0
Australia
Primary sponsor type
Individual
Name
A/Professor Denise O'Driscoll - Eastern Health
Address
Country
Australia
Secondary sponsor category [1] 322140 0
None
Name [1] 322140 0
Address [1] 322140 0
Country [1] 322140 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 318196 0
Eastern Health Human Research Ethics Committee
Ethics committee address [1] 318196 0
Ethics committee country [1] 318196 0
Australia
Date submitted for ethics approval [1] 318196 0
15/08/2025
Approval date [1] 318196 0
Ethics approval number [1] 318196 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 143414 0
A/Prof Denise O'Driscoll
Address 143414 0
Box Hill Hospital, Level 5, 8 Arnold St, Box Hill, Victoria 3128
Country 143414 0
Australia
Phone 143414 0
+61 3 99756538
Fax 143414 0
Email 143414 0
[email protected]
Contact person for public queries
Name 143415 0
Denise O'Driscoll
Address 143415 0
Box Hill Hospital, Level 5, 8 Arnold St, Box Hill, Victoria 3128
Country 143415 0
Australia
Phone 143415 0
+61 3 99756538
Fax 143415 0
Email 143415 0
[email protected]
Contact person for scientific queries
Name 143416 0
Denise O'Driscoll
Address 143416 0
Box Hill Hospital, Level 5, 8 Arnold St, Box Hill, Victoria 3128
Country 143416 0
Australia
Phone 143416 0
+61 3 99756538
Fax 143416 0
Email 143416 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
Yes
Will there be any conditions when requesting access to individual participant data?
Persons/groups eligible to request access:
• Researchers
Conditions for requesting access:
• Yes, conditions apply:
• Requires review on a case-by-case basis by the trial custodian, sponsor or data sharing committee
• Requires a scientifically sound proposal or protocol
• Requires approval by an ethics committee
• Requires a data sharing agreement between data requester and trial custodian or sponsor
What individual participant data might be shared?
• All de-identified individual participant data
What types of analyses could be done with individual participant data?
• Systematic reviews and meta-analyses
When can requests for individual participant data be made (start and end dates)?
From:
After publication of main results
To:
Not yet decided
Where can requests to access individual participant data be made, or data be obtained directly?
• Postal address: Sleep Laboratory, Box Hill Hospital, 8 Arnold St, Box Hill, Victoria 3128

Are there extra considerations when requesting access to individual participant data?
No


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.