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Trial registered on ANZCTR


Registration number
ACTRN12615000198527
Ethics application status
Approved
Date submitted
17/02/2015
Date registered
2/03/2015
Date last updated
24/03/2017
Type of registration
Prospectively registered

Titles & IDs
Public title
A randomized-controlled-trial of passive heating or cooling to improve sleep and facilitate weight loss in overweight/obese individuals.
Scientific title
A randomized-controlled-trial of passive heating or cooling to improve sleep and facilitate weight loss in overweight/obese individuals.
Secondary ID [1] 286195 0
Nil
Universal Trial Number (UTN)
U1111-1167-2153
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 294226 0
Condition category
Condition code
Diet and Nutrition 294546 294546 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
In this randomized controlled trial (RCT), we will evaluate the effects of instructing overweight/ obese individuals to take a hot or cold bath/shower (whichever is preferred) about 90-minutes prior to the time they wish to go to sleep, to determine whether this is effective in: (a) improving their sleep quality and increasing sleep times, and (b) as a consequence of going to bed earlier and sleeping a longer time, eat substantially less at night and therefore reduce their weight over time, relative to the control group participants. Based on the empirical studies where participants took a hot bath/shower as a modality of passive body heating (Allehe et al. 2013; Cynthia, 1996), the water temperature was 41-42 degrees Celsius. In our study, we will advise the participants who are taking a hot bath/shower to make it as hot as they feel comfortable with, which should be around this water temperature. However, it is important not to give too detailed instructions that are disparate in extent to the participants who instead seek to take a cold bath/show. The participants will also be asked to complete the study questionnaire prior to being randomized to a study group, then they will participate in their group’s activities for 3-months (i.e. reviewing and enacting the sleep hygiene information), and then completing the follow-up questionnaire. Finally, the intervention condition will involve the participants either taking a hot/cold bath or shower every night for 3-months, whichever is preferred), and completing the baseline and follow-up questionnaires.

Several strategies will be used to ensure that the study participants do adhere to the instructions they received. First, we will instruct them to complete the diary as accurately as they can and remind them that we are not testing them, but rather the effectiveness of a potential new weight loss program. Third, we will telephone all participants (including the control group participants) after 1-week and 1-month to check on their engagement in their group activities, and to remind them to complete the questionnaire at the end of the study.
Intervention code [1] 291211 0
Lifestyle
Intervention code [2] 291212 0
Behaviour
Comparator / control treatment
The first control condition is a Normal bedtime protocol group . Participants who are randomised to this group will simply be asked to complete the same questionnaires that are being completed by the other two study groups. The second control condition involves the participants reading an information page about typical sleep hygiene training (i.e. ways in which they might improve their sleep, e.g. reduce caffeine intake after lunch, don’t use too much bedding, etc.). This sheet is simply an instruction sheet designed for the study and attached with a daily diary sent to the participants via email after they will be randomised to the allocated group. Reading the instructions and filling up the diary wont take 10 minutes. They will also be asked to complete the study questionnaire (detailed below) prior to being randomized to a study group, then they will participate in their group’s activities for 3-months (i.e. reviewing and enacting the sleep hygiene information), and then completing the follow-up questionnaire. Finally, the intervention condition will involve the participants either taking a hot/cold bath or shower every night for 3-months, whichever is preferred), and completing the baseline and follow-up questionnaires
Control group
Active

Outcomes
Primary outcome [1] 294325 0
Weight loss.
This outcome will be assessed using digital weighing scale.
Timepoint [1] 294325 0
at 3 months after randomisation
Primary outcome [2] 294326 0
Quality of sleep assessed using the Pittsburgh Sleep Quality Index (PSQI)
Timepoint [2] 294326 0
at 3 months after randomization
Secondary outcome [1] 313051 0
Physical activity levels assessed using physical activity diary and the Global Physical Activity Questionnaire v2.0
Timepoint [1] 313051 0
at 3 months period after randomization
Secondary outcome [2] 313204 0
Night eating assessed using the Night Eating Questionnaire (NEQ).
Timepoint [2] 313204 0
At 3 months after Randomization
Secondary outcome [3] 313205 0
Binge-eating assessed using the Binge-Eating Scale (BES).

Timepoint [3] 313205 0
at 3 months after randomization

Eligibility
Key inclusion criteria
Criteria for Inclusion Study inclusion criteria are as follows: (i) participants are required to be overweight or obese; (ii) over 18 years and less than 66 years of age, and (iii) able to bathe themselves or have a regular carer who can arrange this for them.

Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Criteria for Exclusion: The study exclusion criteria are detailed as follows: including people who are: (i) under 18 years of age or older than 65-years; (ii) underweight or normal weight; or (iii) pregnant.

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)
Participants will be randomly assigned to one of the three groups using a random-generator computer program.

Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomly assigned to one of the three groups using a random-generator computer program.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis
In regards to the justification of the sample size, and based on the small relevant studies of passive body heating on body temperature and sleep, the largest sample had 23 participants in each group, and the smallest subsample had 5 participants. Nonetheless, an a priori power analysis is provided separately for the planned between-groups analyses. In the between-groups analyses (i.e.1 experimental vs 2 control groups), this calculation was based on an estimated effect size of .25 (small to moderate), with alpha set at .05, power set at .9, and using up to 6 predictors, critical F(6,70)=2.23. This calculation indicated that only N=77 participants were required, i.e. about 25 participants in each of the three groups. The between-groups analyses will evaluate whether the intervention condition can facilitate weight loss over 3-months, relative to the study control groups.

Recruitment
Recruitment status
Withdrawn
Reason for early stopping/withdrawal
Participant recruitment difficulties
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 in Australia
Recruitment state(s)
ACT
Recruitment outside Australia
Country [1] 6671 0
Canada
State/province [1] 6671 0
vancouver

Funding & Sponsors
Funding source category [1] 290768 0
University
Name [1] 290768 0
The Australian National University
Address [1] 290768 0
Canberra ACT 2601

PO Box 0200


Country [1] 290768 0
Australia
Primary sponsor type
University
Name
Australian National University
Address
The Australian National University

Canberra ACT 2601

PO Box 0200
Country
Australia
Secondary sponsor category [1] 289452 0
None
Name [1] 289452 0
Address [1] 289452 0
Country [1] 289452 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292399 0
Human ethics - Research Services - ANU
Ethics committee address [1] 292399 0
Human Ethics Manager
Research Integrity & Compliance,
Research Services,
Ground Floor, Chancelry 10B
Ellery Crescent,
The Australian National University
ACTON ACT 2601

Ethics committee country [1] 292399 0
Australia
Date submitted for ethics approval [1] 292399 0
08/04/2016
Approval date [1] 292399 0
29/04/2016
Ethics approval number [1] 292399 0
2015/013

Summary
Brief summary
In this study, a number of specific between-groups hypotheses will be tested in the randomized controlled trial as detailed below:

H1: Participants in the experimental group will experience improved sleep quality, relative to the study controls, between baseline and follow-up at 3-months;

H2: Participants in the experimental group will lose a greater amount of weight, relative to the study controls, between baseline and follow-up at 3-months;

Further, a number of within-subjects hypotheses will be tested:

H3: The relationship between study group (i.e. hot/cold bath vs. study controls) and weight loss between baseline and 3-months follow-up will be mediated by the drop in mean core body temperature and improved sleep quality; and,

H4: The relationship between study group and weight loss between baseline and 3-months will be mediated by a reduction in binge- and/or night-time eating, which is due to the longer time spent asleep and less time sitting up at night. That is, participants who do not engage in eating late at night are expected to lose more weight than those who do eat late at night.

In the analyses pertaining to the hypotheses, we will control for all variables that are correlated with the outcome variables (i.e. sleep quality, and BMI), including symptoms of anxiety/ depression and a lack of exercise/physical activity, as well as certain conditions (e.g. hypothyroidism) or treatments (e.g. antidepressants), if appropriate.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 55018 0
Ms Shireen Eid
Address 55018 0
The Australian National University

Canberra ACT 2601

PO Box 0200

Country 55018 0
Australia
Phone 55018 0
+61402011004
Fax 55018 0
Email 55018 0
shireen.eid@anu.edu.au
Contact person for public queries
Name 55019 0
A/Prof Rhonda Brown
Address 55019 0
The Australian National University
CANBERRA ACT 2601
PO Box 0200

Country 55019 0
Australia
Phone 55019 0
+61 2 6125 0635
Fax 55019 0
Email 55019 0
rhonda.brown@anu.edu.au
Contact person for scientific queries
Name 55020 0
A/Prof Rhonda Brown
Address 55020 0
The Australian National University
CANBERRA ACT 2601
PO Box 0200
Country 55020 0
Australia
Phone 55020 0
+61 2 6125 0635
Fax 55020 0
Email 55020 0
rhonda.brown@anu.edu.au

No information has been provided regarding IPD availability
Summary results
No Results