Assessment of Six-minute Walking Distance 6MWD Between High Altitude HA vs. Sea Level LA in Healthy Individuals H

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 descent from high altitude (Quito Ecuador: 2850m) to sea level on six-minute walking distance and scores in healthy individuals, who live permanently >2600m.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The aim of this research is to investigate the six-minute walking distance and scores before and after descent (high altitude near their living altitude vs. sea level) in healthy individuals, who permanently live at high altitude over 2600m.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
14

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Six-minute walking distance 6MWD at sea level
Assessment of the six-minute walking distance and scores near their resident altitude at 2850m followed by a descent from 2850m to sea level by bus with a stay for 7 days and again assessment of the same outcomes
Behavioral: Descent from 2850m to sea level
Descent from 2850m to sea level with stay for 7 days

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Six-minute walking distance after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in six-minute walking distance in meter (6MWD) between 2850m and Day 5-7 at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
SpO2 (%) at rest and end-exercise after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise between 2850m and Day 5-7 at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
Heart rate (beats per minute) at rest and end-exercise after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in heart rate at rest and end-exercise between 2850m and Day 5-7 at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
Blood pressure (mmHg) at rest and end-exercise after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in blood pressure at rest and end-exercise between 2850m and Day 5-7 at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
Dyspnea and leg discomfort sensation after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in dyspnea and leg discomfort sensation (assessed with BORG-CR10-Scale, Category Rating 0-10 with 10 being the most dyspnea/leg discomfort) at rest and end-exercise between 2850m and 5-7 days at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
NYHA functional class (1-4) after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) at rest and end-exercise between 2850m and 5-7 days at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
Quality of life after 7 days at sea level
Time Frame: From high altitude (2850m) to day 5-7 at sea level
Difference/change in quality of life score (EmPHasis-10: Score with 10 questions and 0-50 points, higher scores indicating poorer quality of life) between 2850m and 5-7 days at sea level in healthy individuals
From high altitude (2850m) to day 5-7 at sea level
General well-being after 7 days at sea level
Time Frame: From high altitude (2850m) to Day 5-7 at sea level
Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) between 2850m and day 5-7 at sea level in healthy individuals
From high altitude (2850m) to Day 5-7 at sea level
Acclimatization-effect of six-minute walking distance (m) at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in six-minute walking distance (6MWD) within a stay at sea level of 7 days (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of SpO2 (%) at rest and end-exercise at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of heart rate (beats per minute) at rest and end-exercise at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in heart rate at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of blood pressure (mmHg) at rest and end-exercise at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in blood pressure at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of dyspnea and leg discomfort at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in dyspnea and leg discomfort (assessed with BORG-CR10-Scale, Category Rating 0-10 with 10 being the most dyspnea/leg discomfort) at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of NYHA functional class (1-4) at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) at rest and end-exercise within a stay of 7 days at sea level (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of Quality of Life at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in quality of life (EmPHasis-10: Score with 10 questions and 0-50 points, higher scores indicating poorer quality of life) within a stay of 7 days at sea level (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level
Acclimatization-Effect of general well-being at sea level
Time Frame: From Day 2 to Day 5-7 at sea level
Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) within a stay of 7 days at sea level (after descent from 2850m) in healthy individuals
From Day 2 to Day 5-7 at sea level

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Silvia Ulrich Somaini

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 25, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 4, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 17, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 31, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Ec_HAvsLA_6MWD_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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