Adaptation of Lung Transplant Recipients at Extreme Altitude

NCT07479511 | Active Not Recruiting

• 2 other identifiers: 2105/2025EK Nr: 2105/2025
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective observational study investigates the effects of intermittent hypoxic conditioning and real high-altitude exposure in lung transplant recipients compared with healthy controls. The study includes an eight-week home-based preparatory phase during which participants use a normobaric hypoxic tent with reduced oxygen concentration. Prior to this phase, all participants receive standardized training on the safe use of the equipment. During the preparatory period, daily vital parameters, including heart rate, oxygen saturation, and heart rate variability, are recorded using a sports watch and a pulse oximeter. Symptoms, adverse events, and subjective well-being are documented daily in an electronic diary. All data are transmitted to the study team via encrypted electronic systems, allowing continuous remote monitoring. At the end of the preparatory phase, participants undergo a clinical evaluation to confirm fitness for the expedition phase. The expedition phase consists of a monitored ascent of Aconcagua (6,971 meters). Before departure, all participants are required to attend a comprehensive safety, protection, and first aid training conducted jointly by the study team and professional expedition providers. The expedition is planned and led by an experienced international expedition company in cooperation with a local provider specializing in high-altitude mountaineering. The expedition includes arrival in Mendoza, preparatory procedures such as equipment checks and permits, followed by a staged ascent to base camp. Subsequent days involve rest periods and acclimatization hikes with the establishment of progressively higher camps. A summit attempt is planned after sufficient acclimatization, followed by descent to high camp. A weather-dependent buffer period is included before the final descent to the valley and return to Mendoza, where the expedition concludes. Total study participation is expected to last approximately 15 weeks, including about eight weeks of home-based preparation and approximately three weeks at altitude. A final follow-up examination is conducted 2 to 4 weeks after completion of the expedition, marking the end of study participation.

Conditions

Lung Transplantation; Hypoxia; Altitude; High-altitude Adaptation; Immunosuppression; Physical Fitness; Oxygen Saturation Measurement; Microbiota

Outcome Measures

Primary Outcomes (2)

• Change in forced expiratory volume in one second (FEV₁)

  From enrollment to the end of the expedition at 3 weeks

• Change in peripheral oxygen saturation (SpO₂) as a marker of physiological adaptation

  From enrollment to the end of the expedition at 3 weeks

Secondary Outcomes (12)

• Heart Rate Variability (HRV)

  From enrollment to the end of the expedition at 3 weeks

• Blood gas analysis (BGA)

  From enrollment to the end of the expedition at 3 weeks

• Acute mountain sickness (AMS)

  From enrollment to the end of the expedition at 3 weeks

• Level of immunosuppression

  From enrollment to the end of the expedition at 3 weeks

• Level of Torque Teno Virus (TTV)

  Before enrollment until approx. 4 weeks after the end of the expedition

Study Arms (2)

Lung transplant recipients

Healthy volunteers

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Lung transplant recipients and Healthy controls

You may qualify if:

• Lung transplant recipients:
• Age ≥ 18 years
• \> 1 years after lung transplantation
• VO2peak of more than 25 ml/min/kg
• Physical and mental fitness, defined as the ability to complete strenuous day trips lasting 8 to 10 hours independently without suffering from a fear of heights, an altitude exposure of at least 2500m must be confirmed.
• Negative pregnancy test for women of childbearing age
• Written informed consent
• Healthy volunteers:
• Age ≥ 18 years
• VO2peak of more than 25 ml/min/kg
• Physical and mental fitness, defined as the ability to complete strenuous day trips lasting 8 to 10 hours independently without suffering from a fear of heights
• Negative pregnancy test for women of childbearing age
• Written informed consent

You may not qualify if:

• Lung transplant recipients:
• Age \< 18 years
• Refusal to participate in the study
• Pregnancy
• Healthy controls:
• Age \< 18 years
• Refusal to participate in the study
• Pregnancy
• Chronic obstructive pulmonary disease (COPD)

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (1)

Medical University of Vienna

Vienna, Vienna, 1090, Austria

Location

Related Links

• Description of the project and the expedition

Biospecimen

Retention: SAMPLES WITHOUT DNA

capillary blood, stool

MeSH Terms

Conditions

Hypoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: M.D, PhD

Study Record Dates

• First Submitted: January 19, 2026
• First Posted: March 18, 2026
• Study Start: January 10, 2026
• Primary Completion: May 30, 2026
• Study Completion: June 30, 2026
• Last Updated: March 18, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1)