Effect of Moderate Altitude (>1000 m.a.s.l.) on Sleep Examinations (Polysomnography).

Not Applicable

Completed

• Conditions: Healthy

• Registration Number: NCT05826808
• Lead Sponsor: Tsogyal Latshang

Brief Summary

The purpose of this study is to investigate the effect of moderate altitude (\>1000 m.a.s.l.) on sleep examinations (polysomnography).

Detailed Description

Polysomnographies will be done for each participant for 2 consecutive nights at the sleep laboratory in Chur (CH; 600 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 Timeline

• Study First Submitted: 2023-03-15
• Study First Submitted QC: 2023-04-12
• Study First Posted: 2023-04-24
• Study Start: 2023-06-30
• Primary Completion: 2024-03-16
• Study Completion: 2024-03-16
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-18
• Last Update Posted: 2025-04-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 44

Inclusion Criteria

• 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

Exclusion Criteria

• 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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
T90 (time spent in SpO2 below 90%)	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.

Secondary Outcome Measures

Name	Time	Method
SWS (slow-wave sleep)	4 nights	SWS includes the deep sleep phase. Deep sleep is amongst other important for energy restoration, immune system strengthening and regeneration of cells.
AI (arousal index)	4 nights	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.
TcCO2 (partial pressure of carbon dioxide)	4 nights	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.
WASO (wakefulness after sleep onset)	4 nights	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.
ODI (oxygen desaturation index)	4 nights	ODI is defined as the number of oxygen decreases ≥3% per hour of sleep.
SpO2 (oxygen saturation)	4 nights	SpO2 is the amount of haemoglobin bound to oxygen. Normal values lie above 95%. Values below 90% are considered as low and require treatment.
AHI (apnea-hypopnea index)	4 nights	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.

Trial Locations

Locations (1)

Kantonsspital Graubünden; 🇨🇭 Chur, Switzerland