HealthyNCT05826808
Effect of Short-term Descent to Low Altitude in Healthy Residents at Moderate Altitude (>1000 m.a.s.l.).
A study testing Descent to low altitude in people with Healthy, run by Tsogyal Latshang at 1 site in Switzerland.
Trial summary
The purpose of this study is to investigate the effect of short-term descent in healthy residents at moderate altitude (>1000 m.a.s.l.). Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Descent to low altitude
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 44 participants
- Where
- 1 siteSwitzerland
- Study dates
- 30 Jun 2023to 16 Mar 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy (no current medical condition or intake of regular medication, except negligible medical issues or accidents not interfering with the current health status or physical performance.)
- Living above 1000 m.a.s.l. since at least 1 year
- No overnight stay at altitudes <1000 m.a.s.l. in the previous 4 weeks
- 18-70 years old
- Body mass index 18,5-30 kg/m2
- informed consent
Who cannot join
- Active diseases or health related conditions that require treatment (sleep disorders (mainly sleep apnea), chronic rhinitis, cardiovascular and lung diseases)
- Use of drugs that affect the respiratory center drive (sedatives, sleep inducing drugs, opioids), stimulants or illegal drugs
- Regular consumption of recreational drugs (alcohol and nicotine included)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Different Diagnostic Values of Polysomnographies at Low and at Moderate Altitude - A Randomized Crossover Trial
The purpose of this study is to investigate the effect of short-term descent in healthy residents at moderate altitude (>1000 m.a.s.l.).
Read the detailed description
Polysomnographies will be done for each participant for 2 consecutive nights at the sleep laboratory in Chur (CH; 590 m.a.s.l.) as well as for 2 consecutive nights at the participants home elevations (CH; >1000 m.a.s.l.). Between the measurements at those two different altitudes there will be a two-week washout period at >1000 m.a.s.l.. The sequence of altitude exposure will be randomized.
- Conditions
- Healthy
- Being tested
- Descent to low altitude
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Descent to low altitudeDiagnostic test
The polysomnographic recordings include electroencephalogram (EEG), electrooculogram (EOG), electromyogram (EMG), electrocardiogram (ECG), pulse oximetry, transcutaneous capnography, nasal airflow and thoracic and abdominal respiratory effort.
| Study group | Role | What they receive |
|---|---|---|
| A | Experimental | Polysomnographies will be done first for 2 nights at the sleep laboratory in Chur (590 m.a.s.l.) and after a two-week washout period for 2 nights at the participants home elevations (>1000 m.a.s.l.). Receives: Diagnostic Test: Descent to low altitude |
| B | Experimental | Polysomnographies will be done first for 2 nights at the participants home elevations (>1000 m.a.s.l.). and after a two-week washout period for 2 nights at sleep laboratory in Chur (590 m.a.s.l.). Receives: Diagnostic Test: Descent to low altitude |
What is being measured
The primary outcome is the main question the study is designed to answer.
T90 (time spent in SpO2 below 90%)
T90 is the percent of sleeping time which the participant spent in SpO2 below 90%. It provides information about the duration and degree of hypoxia during the whole sleep.
Measured: 4 nights
Secondary outcomes (7)
SpO2 (oxygen saturation)
SpO2 is the amount of haemoglobin bound to oxygen. Normal values lie above 95%. Values below 90% are considered as low and require treatment.
Measured: 4 nights
AHI (apnea-hypopnea index)
AHI is defined as the number of apneas and hypopneas per hour of sleep, whereby apnea is defined as a cessation of the airflow for ≥10 seconds, while hypopnea is defined as a reduction of the airflow ≥30% with an oxygen desaturation ≥3% or an arousal.
Measured: 4 nights
SWS (slow-wave sleep)
SWS includes the deep sleep phase. Deep sleep is amongst other important for energy restoration, immune system strengthening and regeneration of cells.
Measured: 4 nights
AI (arousal index)
AI is the number of arousals per hour of sleep, whereby an arousal is an interruption of sleep from 3-15 seconds. They prevent suffocation in the sleep apnea by interrupting breathing pauses but are also coupled with a lot of stress for the human body.
Measured: 4 nights
TcCO2 (partial pressure of carbon dioxide)
TcCO2 correlates with PaCO2 and is therefore a non-invasive alternative. A normal value of PCO2 lies between 35 and 45 mmHg. Lower values can lead to muscle cramps, abnormal heartbeat and much more.
Measured: 4 nights
WASO (wakefulness after sleep onset)
WASO is the time spent awake after sleep onset. High values of WASO are for example found in sleep apnea, insomnia and restless leg syndrome.
Measured: 4 nights
ODI (oxygen desaturation index)
ODI is defined as the number of oxygen decreases ≥3% per hour of sleep.
Measured: 4 nights
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2023
- Study start30 Jun 2023
- Primary completion16 Mar 2024
- Study completion16 Mar 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 44 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tsogyal Latshang
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Tsogyal Latshang, Kantonsspital Graubünden
- Investigators
- Tsogyal Latshang, PD Dr. med., Principal investigator, Kantonsspital Graubünden
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05826808
- Sponsor's protocol ID
- 2023-00636
- Other IDs
- 2023
- Status last verified
- Apr 2025
- First submitted
- 15 Mar 2023
- Last updated
- 18 Feb 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Deflorin N, Furian M, Vontobel J, Niederseer D, Latshang TD. The effect of short-term descent to low altitude in healthy residents at moderate altitude - a randomized crossover trial. J Clin Sleep Med. 2026 Jul 22;22(1):122. doi: 10.1007/s44470-026-00128-1.
PubMed 42484958
Study at a glance
From the registry record, last updated by the sponsor on 18 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Different Diagnostic Values of Polysomnographies at Low and at Moderate Altitude - A Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT05826808
- Acronym / sponsor ID
- 2023-00636
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 44 participants (actual)
- Lead sponsor
- Tsogyal LatshangUniversity, hospital or other
- Study start
- 30 Jun 2023 (actual)
- Primary completion
- 16 Mar 2024 (actual)
- Study completion
- 16 Mar 2024 (actual)
- First posted
- 24 Apr 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to investigate the effect of short-term descent in healthy residents at moderate altitude (>1000 m.a.s.l.).
Detailed description
Polysomnographies will be done for each participant for 2 consecutive nights at the sleep laboratory in Chur (CH; 590 m.a.s.l.) as well as for 2 consecutive nights at the participants home elevations (CH; >1000 m.a.s.l.). Between the measurements at those two different altitudes there will be a two-week washout period at >1000 m.a.s.l.. The sequence of altitude exposure will be randomized.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| A | Experimental | Diagnostic Test: Descent to low altitudePolysomnographies will be done first for 2 nights at the sleep laboratory in Chur (590 m.a.s.l.) and after a two-week washout period for 2 nights at the participants home elevations (>1000 m.a.s.l.). |
| B | Experimental | Diagnostic Test: Descent to low altitudePolysomnographies will be done first for 2 nights at the participants home elevations (>1000 m.a.s.l.). and after a two-week washout period for 2 nights at sleep laboratory in Chur (590 m.a.s.l.). |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Healthy (no current medical condition or intake of regular medication, except negligible medical issues or accidents not interfering with the current health status or physical performance.)
- Living above 1000 m.a.s.l. since at least 1 year
- No overnight stay at altitudes <1000 m.a.s.l. in the previous 4 weeks
- 18-70 years old
- Body mass index 18,5-30 kg/m2
Key exclusion criteria (3 listed)
- Active diseases or health related conditions that require treatment (sleep disorders (mainly sleep apnea), chronic rhinitis, cardiovascular and lung diseases)
- Use of drugs that affect the respiratory center drive (sedatives, sleep inducing drugs, opioids), stimulants or illegal drugs
- Regular consumption of recreational drugs (alcohol and nicotine included)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Descent to low altitudeThe polysomnographic recordings include electroencephalogram (EEG), electrooculogram (EOG), electromyogram (EMG), electrocardiogram (ECG), pulse oximetry, transcutaneous capnography, nasal airflow and thoracic and abdominal respiratory effort. | Diagnostic test | A, B |
Primary outcome
T90 (time spent in SpO2 below 90%)
Time frame: 4 nights
T90 is the percent of sleeping time which the participant spent in SpO2 below 90%. It provides information about the duration and degree of hypoxia during the whole sleep.
7 secondary outcomes
SpO2 (oxygen saturation)
Time frame: 4 nights
AHI (apnea-hypopnea index)
Time frame: 4 nights
SWS (slow-wave sleep)
Time frame: 4 nights
AI (arousal index)
Time frame: 4 nights
TcCO2 (partial pressure of carbon dioxide)
Time frame: 4 nights
WASO (wakefulness after sleep onset)
Time frame: 4 nights
ODI (oxygen desaturation index)
Time frame: 4 nights
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Feb 2026.
- Derived from this study: PubMed 42484958Deflorin N, Furian M, Vontobel J, Niederseer D, Latshang TD. The effect of short-term descent to low altitude in healthy residents at moderate altitude - a randomized crossover trial. J Clin Sleep Med. 2026 Jul 22;22(1):122. doi: 10.1007/s44470-026-00128-1.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tsogyal Latshang, PD Dr. med. principal investigator
Kantonsspital Graubünden
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Descent to low altitude in people with Healthy, run by Tsogyal Latshang at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
T90 (time spent in SpO2 below 90%) (time frame: 4 nights). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05826808, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Feb 2026; AzTrials last refreshed its copy on 7 Nov 2026.