Impact of a simulated multiday heatwave on nocturnal physiology, behavior, and sleep
| ISRCTN | ISRCTN67760213 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN67760213 |
| Secondary identifying numbers | Horizon Grant No. 668786, Slovenian Research and Innovation Agency grant no. P2-0076 |
- Submission date
- 17/05/2024
- Registration date
- 27/05/2024
- Last edited
- 16/07/2024
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
This study looks at how a multiday heatwave affects nighttime physiology, behavior, and sleep under controlled conditions, with careful monitoring of the environment and participant activities. The study aims to enhance our knowledge regarding the impact of heatwaves on human physiology, cognition, behavior, and sleep. Currently, there are no physiological studies investigating the impact of this unique weather phenomenon in laboratory settings that enable comprehensive and precise assessment of multiple physiological and behavioral responses in humans.
Who can participate?
Healthy young men with no history of sleep disorders or medication use
What does the study involve?
Participants will be kept in a controlled environment for ten days. The temperature will be hot-to-warm (day: 35.4°C, night: 26.3°C) during nights 4-6 and moderate (day: 25.4°C, night: 22.3°C) before (nights 1-3) and after (nights 7-10) the heatwave. Measurements to be taken include core and skin temperatures, heart rate, balance between sympathetic and parasympathetic nervous systems, indicators of skin blood flow, urine samples, blanket usage, subjective sleep quality assessments, and partial sleep monitoring.
What are the possible benefits and risks of participating?
The benefits of this study for our participants are that (i) they will learn more about the physiology of their bodies and, most importantly, (ii) they will have the opportunity to contribute to a unique state-of-the-art physiological study that will expand current knowledge on the impact of heatwaves on humans.
Regarding the risks of participating, the present study simulates a frequent weather phenomenon that participants have already experienced many times in their lives. The safety of the laboratory settings ensures that there will be no negative impacts on the health of the participants, although they may feel more tired during the heatwave simulation.
Where is the study run from?
Jožef Stefan Institute
When is the study starting and how long is it expected to run for?
June 2020 to November 2020
Who is funding the study?
1. Horizon 2020
2. Slovenian Research and Innovation Agency
Who is the main contact?
Dr Leonidas Ioannou, ioannoulg@gmail.com
Contact information
Public, Scientific, Principal Investigator
Jamova Cesta 39
Ljubljana
1000
Slovenia
 ORCID ID |
0000-0001-5460-8167 |
|---|---|
| Phone | +306949963364 |
| leonidas.ioannou@ijs.si |
Study information
| Study design | Interventional study |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Non randomised study |
| Study setting(s) | Laboratory |
| Study type | Quality of life, Safety |
| Participant information sheet | 45487_PIS_24Aug2020.pdf |
| Scientific title | Impact of a simulated multiday heatwave on nocturnal physiology, behavior, and sleep: A 10-day confinement study |
| Study acronym | HEATWAVE |
| Study objectives | This study hypothesizes that prolonged exposure to heatwave conditions will significantly alter nocturnal physiology, thermoregulatory behavior, and sleep, including changes in the thermoregulatory mechanisms of skin vasomotion and sweating rate (reflected in urine dehydration markers), as well as variations in blanket coverage and sleep quality indicators, compared to neutral conditions. |
| Ethics approval(s) |
Approved 20/10/2020, National Committee for Medical Ethics of the Republic of Slovenia (Štefanova ulica 5, Ljubljana, 1000, Slovenia; +386 01 478 60 01; gp.mz@gov.si), ref: 0120-402/2020/4 |
| Health condition(s) or problem(s) studied | Impact of a simulated heatwave on physiology, behavior, and sleep. |
| Intervention | This study will monitor physiological and behavioral responses to a 3-day heatwave throughout the day and over ten days. During this period, three days (days 5 to 7) are dedicated to a heatwave (day: 35.4 °C; night: 26.3 °C) simulation, while days 1 to 4 and 8 to 10 are thermally neutral (day: 25.4 °C; night: 22.3 °C). |
| Intervention type | Behavioural |
| Primary outcome measure | 1. Core body temperature measured using telemetric pills continuously 2. Skin temperature from four sites measured using iButtons continuously 3. Heart rate measured using heart rate monitors continuously 4. Sleep quality measured using a partial polysomnography device continuously 5. Sleep thermoregulatory behavior measured using photographs taken once per night, and with a questionnaire once per day 6. Dehydration measured using urine-specific gravity once per day |
| Secondary outcome measures | There are no secondary outcome measures |
| Overall study start date | 01/06/2020 |
| Completion date | 01/11/2020 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Male |
| Target number of participants | 7 |
| Total final enrolment | 7 |
| Key inclusion criteria | 1. Non-heat acclimatized 2. Healthy, young males 3. Without a history of sleep disorders or medication use |
| Key exclusion criteria | 1. Unhealthy 2. Non-adult |
| Date of first enrolment | 21/10/2020 |
| Date of final enrolment | 22/10/2020 |
Locations
Countries of recruitment
- Slovenia
Study participating centre
Ljubljana
1000
Slovenia
Sponsor information
Research organisation
Jamova cesta 39
Ljubljana
1000
Slovenia
| Phone | +386 1 477 3358 |
|---|---|
| igor.mekjavic@ijs.si | |
| Website | https://www.ijs.si/ijsw |
"ROR" |
https://ror.org/05060sz93 |
Funders
Funder type
Government
Government organisation / National government
- Alternative name(s)
- EU Framework Programme for Research and Innovation, Horizon 2020 - Research and Innovation Framework Programme, European Union Framework Programme for Research and Innovation
No information available
Results and Publications
| Intention to publish date | 01/07/2024 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Planned publication in a peer-reviewed journal |
| IPD sharing plan | The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Leonidas Ioannou, ioannoulg@gmail.com. The type of data that will be shared will be a spreadsheet file with physiological responses, which will be available five years after the data collection. Written informed consent was obtained from participants. Data are fully anonymized and stored in an encrypted format. No participant data that may affect the confidentiality (anonymity) of our participants will be shared. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | 24/08/2020 | 22/05/2024 | No | Yes | |
| Results article | 25/06/2024 | 16/07/2024 | Yes | No |
Additional files
Editorial Notes
16/07/2024: Publication reference added.
20/05/2024: Study's existence confirmed by the Republic of Slovenia Ministry of Health National Committee for Medical Ethics.
