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

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: Not yet recruiting
• Conditions: Healthy; Healthy Adult; High Altitude; High Altitude Effects; Six-minute Walk Test
• Intervention / Treatment: Behavioral: Descent from 2850m to sea level

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: Interventional
• Enrollment (Estimated): 14
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Silvia Ulrich, Prof. Dr. med.; Phone Number: +41442552220; Email: silvia.ulrich@usz.ch
• Study Contact Backup: Name: Michael Furian, Prof. Dr. sc. ETH; Phone Number: +41442552220

Study Locations

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

Participation Criteria

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

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Six-minute walking distance after 7 days 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

Outcome Measure	Measure Description	Time Frame
SpO2 (%) at rest and end-exercise after 7 days 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	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	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	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	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	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	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	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	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	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	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	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	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	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	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

• 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

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 3, 2026

Study Record Updates

• Last Update Posted (Actual): September 3, 2026
• Last Update Submitted That Met QC Criteria: August 31, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: hypoxia; high altitude; NYHA; six-minute walking distance
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia; Altitude Sickness
• Other Study ID 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