Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12622000415707
Ethics application status
Approved
Date submitted
25/02/2022
Date registered
11/03/2022
Date last updated
11/03/2022
Date data sharing statement initially provided
11/03/2022
Date results information initially provided
11/03/2022
Type of registration
Retrospectively registered

Titles & IDs
Public title
The investigation of odour concentrations using natural odours on the autonomic (unconscious) nervous system in healthy-adult human volunteers.
Scientific title
To investigate the effects of low-high concentrations of specific odours using an olfactometer delivery on heart-rate variability measured using electrocardiogram on the healthy-adult human population.
Secondary ID [1] 306520 0
Nil known
Universal Trial Number (UTN)
Trial acronym
AMVOS- Autonomic nervous system Modulation Via Odour Stimulation
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Autonomic nervous system 325408 0
Condition category
Condition code
Neurological 322802 322802 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Use of odourants (natural - Mushroom, lavender, jasmine and rose) in three concentrations (low-5-12.5PPM (Parts per million), moderate-33-50PPM and high-175-200PPM) to observe activation from the autonomic nervous system using an electrocardiogram. The concentrations for each odour were chosen from pre-experiment benchtop testing that indicated that participants could significant differentiate these concentrations of the odours (low-mod-high comparisons of each odour). Here, we will observe activity from the sympathetic and parasympathetic nervous systems using heart-rate variability parameters of the ECG. Specific focus is on the parasympathetic nervous system as this is associated with vagal activation, important for the restoration (or improvement) of sympathovagal balance.

We will provide brief 1-min delivery of each odour in each concentration. There will be four deliveries (including sham - air) per day using the same odour (low, moderate and high concentrations). There is a total of four days (for the four different odours). There will be a washout period of 24 hours per session (between different odours).

The study design: 24-min per session
4-min of 'treatment'; 4-min baseline, 1-min odour + 3-min baseline x 4 and final 4-min baseline.

The experimenter will set up an automated sequence of odour delivery on the olfactometer device.

The mode of odour delivery is an olfactometer device that will allow the delivery of the odour through the nose piece into the nose. The odour is provided by the Food Science department at the University of Otago. The Food Science department acquires their odours from 'https://www.purenature.co.nz/collections/essential-oils'.

The location of the experiment is in the 3rd floor Hercus Building (Room 319) Cakmak human laboratory.
Intervention code [1] 322947 0
Treatment: Devices
Comparator / control treatment
Active control - air through the olfactometer device.

One of the 1-min odour = active control - air.
Control group
Active

Outcomes
Primary outcome [1] 330575 0
Observe the effect of specific odours and respective concentrations (low, moderate and high) of each odour on root mean square of successive differences between normal heartbeats (RMSSD) in the time-domain electrocardiogram (ECG).
Timepoint [1] 330575 0
In the 3-min baseline comparisons after the odour delivery (vs active control)
Secondary outcome [1] 406733 0
Observe the effect of specific odours and respective concentrations (low, moderate and high) of each odour on low-frequency and high-frequency power in the frequency-domain electrocardiogram (ECG).
Timepoint [1] 406733 0
In the 3-min baseline comparisons after the odour delivery (vs active control)
Secondary outcome [2] 406736 0
Observe the effect of specific odours and respective concentrations (low, moderate and high) of each odour on pupil dilation in the eye-tracker glasses.
Timepoint [2] 406736 0
In the 3-min baseline comparisons after the odour delivery (vs active control)

Eligibility
Key inclusion criteria
Volunteers that are healthy-adult, male and female of a specified age (19-39 years), with no history of illness or conditions that could affect their sense of smell, vision or electrocardiogram recordings.

Volunteers who are non-smokers or have a diagnosis of anosmia.

For the female participants, only recruiting females who are not on hormonal contraceptives (as we are measuring two stages of the menstrual cycle).
Minimum age
19 Years
Maximum age
39 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Volunteers who are outside the age range, whom are smokers or have a history of anosmia.

Female volunteers who are on hormonal contraceptives (as it would create difficulty with calculating menstrual cycle stages.

Volunteers who have health conditions associated with the cardiovascular system or have chronic inflammatory disorders. This would cause issues with the sympathovagal balance recordings from the electrocardiogram.

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)
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 (Compusense random sequence generator)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
We will recruit 21 healthy males and 21 healthy females based G-Power analysis of results with a similar design (ethic code: H19/108) (primary aim: Effect of different concentrations (low vs high) of odours on HRV observed using RMSSD on an ECG – paired t-test-Means: Differences between two dependent means (matched pairs): tail(s): two (as MNS could increase or reduce RMSSD), Effect size dz: 0.76 (based on our previous research looking at the effect of MNS with odour congruence on HRV; ethics number: H19/108), alpha error probability: 0.05, Power: 0.9.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
24/11/2020
Date of last participant enrolment
Anticipated
Actual
8/08/2021
Date of last data collection
Anticipated
Actual
8/08/2021
Sample size
Target
42
Accrual to date
Final
42
Recruitment outside Australia
Country [1] 24603 0
New Zealand
State/province [1] 24603 0
Otago

Funding & Sponsors
Funding source category [1] 310864 0
University
Name [1] 310864 0
University of Otago - PBRF fund
Country [1] 310864 0
New Zealand
Primary sponsor type
University
Name
University of Otago
Address
University of Otago, Department of Anatomy, Lindo Ferguson Building, 270 Great King St., Dunedin 9016, New Zealand
Country
New Zealand
Secondary sponsor category [1] 312129 0
None
Name [1] 312129 0
Address [1] 312129 0
Country [1] 312129 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 310426 0
University of Otago Human Ethics Committee (Health)
Ethics committee address [1] 310426 0
1st Floor Scott/Shand House, 90 St David's Street, PO Box 56, Dunedin 9054, Otago, New Zealand.
Ethics committee country [1] 310426 0
New Zealand
Date submitted for ethics approval [1] 310426 0
Approval date [1] 310426 0
03/11/2020
Ethics approval number [1] 310426 0
H20/123

Summary
Brief summary
To investigate the use of natural odours in three concentrations to observe its effects on the autonomic (unconscious) nervous system measured using an electrocardiogram in healthy-adult human volunteers.

We hypothesis that natural odours (at specific concentrations) will have odour-concentration specific effects on the autonomic (unconscious) nervous system measured using an electrocardiogram respective to the sex of the cohort.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 117626 0
A/Prof Yusuf Ozgur Cakmak
Address 117626 0
Department of Anatomy, School of Biomedical Sciences, University of Otago, Lindo Ferguson Building, 270 Great King Street, 9054, Dunedin
Country 117626 0
New Zealand
Phone 117626 0
+64 034793040
Fax 117626 0
Email 117626 0
yusuf.cakmak@otago.ac.nz
Contact person for public queries
Name 117627 0
A/Prof Yusuf Ozgur Cakmak
Address 117627 0
Department of Anatomy, School of Biomedical Sciences, University of Otago, Lindo Ferguson Building, 270 Great King Street, 9054, Dunedin
Country 117627 0
New Zealand
Phone 117627 0
+64 034793040
Fax 117627 0
Email 117627 0
yusuf.cakmak@otago.ac.nz
Contact person for scientific queries
Name 117628 0
A/Prof Yusuf Cakmak
Address 117628 0
Department of Anatomy, School of Biomedical Sciences, University of Otago, Lindo Ferguson Building, 270 Great King Street, 9054, Dunedin
Country 117628 0
New Zealand
Phone 117628 0
+64 034793040
Fax 117628 0
Email 117628 0
yusuf.cakmak@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Average data from the ECG and eye tracker for each participant in each period (3-min baseline) after the odour delivery.
When will data be available (start and end dates)?
After publication of the article associated with the data. Roughly around 1/12/2022 till no end date.
Available to whom?
All
Available for what types of analyses?
Any, potentially meta-analysis on the topic.
How or where can data be obtained?
Access subject to approval by Principal investigator (yusuf.cakmak@otago.ac.nz)


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
SourceTitleYear of PublicationDOI
EmbaseNon-contact neuromodulation of the human autonomic nervous system function via different odors: Sex, menstrual cycle, and odor dose- and duration-specific effects.2022https://dx.doi.org/10.3389/fnins.2022.950282
N.B. These documents automatically identified may not have been verified by the study sponsor.