Assessment of Lung Function (Lufu) at Sea Level LA vs. High Altitude HA in Healthy Individuals

August 31, 2026 updated by: Silvia Ulrich Somaini

Effect of a One-week Descent From 2850m to Sea Level and Re-ascent in Patients With Pulmonary Arterial Hypertension and Healthy Controls Permanently Living > 2600m on Pulmonary Hemodynamics, Exercise Capacity, Blood Oxygenation, Sleep Disordered Breathing and Further Outcomes

To study the effect of a re-ascent to high altitude (Quito Ecuador: 2850m) after a one-week stay at sea level (after prior descent from 2850m) on lung function and pulmonary resistance/reactance in healthy individuals, who live permanently > 2600m.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

The aim of this research is to investigate the lung function and pulmonary resistance/reactance before and after re-ascent (sea level for 7 days after prior descent from 2850m vs. re-ascent to 2850m) in healthy individuals, who permanently live at high altitude over 2600m.

Study Type

Interventional

Enrollment (Estimated)

14

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Michael Furian, Prof. Dr. sc. ETH
  • Phone Number: +41442552220

Study Locations

  • Switzerland
      • Zurich, Switzerland, 8091
        • University Hospital of Zürich

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults aged 18-80 years and of all genders
  • Permanent residence > 2600 m
  • healthy: no self perceived cardiopulmonary disease limiting daily activities
  • written informed consent to participate in the study.

Exclusion Criteria:

  • Age <18 years or >80 years
  • Participants who cannot follow the study investigations
  • Participants permanently living < 2600m
  • Participants who traveled and stayed overnight at altitudes <2000 m in the past 4 weeks.
  • any self-perceived cardiopulmonary disease limiting daily activities

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lung function at sea level and at 2850m
Assessment of lung function and pulmonary resistance/reactance on day four at sea level (after prior descent from 2850m) and after re-ascent (after totally one week at sea level) back to 2850m by bus (in one day)
Behavioral: Re-ascent from sea level to 2850m
Descent from 2850m to sea level with a stay for 7 days and re-ascent/return back to their usual living altitude at 2850m

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
FEV1 after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in forced expiratory volume in one second FEV1 between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Forced Vital Capacity FVC after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in forced vital capacity FVC between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)
FEV1/FVC after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in FEV1/FVC between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)
Respiratory Impedance (forced oscillation technique) after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in respiratory impedance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)
Respiratory resistance (forced oscillation technique) after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in respiratory resistance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)
Respiratory reactance (forced oscillation technique) after re-ascent to 2850m
Time Frame: From Day 4 at sea level to the day after re-ascent (Day 9)
Difference/change in respiratory reactance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in healthy individuals
From Day 4 at sea level to the day after re-ascent (Day 9)
FEV1 after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in FEV1 between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
Forced Vital Capacity FVC after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in forced vital capacity FVC between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
FEV1/FVC after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in FEV1/FVC between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
Respiratory Impedance (forced oscillation technique) after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in respiratory Impedance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
Respiratory resistance (forced oscillation technique) after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in respiratory resistance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
Respiratory reactance (forced oscillation technique) after 4 days at sea level
Time Frame: From high altitude (2850m) to day 4 at sea level
Difference/change in respiratory reactance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in healthy individuals
From high altitude (2850m) to day 4 at sea level
FEV1 pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in FEV1 at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Forced Vital Capacity FVC pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in forced vital capacity FVC at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
FEV1/FVC pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in FEV1/FVC at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory Impedance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in respiratory impedance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory resistance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in respiratory resistance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory reactance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time Frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Difference/change in respiratory reactance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in healthy individuals
Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Silvia Ulrich Somaini

Investigators

  • Principal Investigator: Silvia Ulrich, University Hospital Zurich, Departement of Pulmonology
  • Principal Investigator: Rodrigo Hoyos, Hospital Carlos Andrade Marin of Quito, Ecuador

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 25, 2026

Primary Completion (Estimated)

October 4, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

August 17, 2026

First Submitted That Met QC Criteria

August 31, 2026

First Posted (Actual)

September 4, 2026

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

August 31, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Ec_LAvsHA_Lufu_H

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be provided upon request and based on a clear intention reviewed by an ethical review board.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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