HighCycle: Effect of Acetazolamide on Pulmonary Artery Pressure in Women Compared to Men

HighCycle: Effect of Acetazolamide on Pulmonary Artery Pressure in Women Compared to Men. A Randomized, Placebo-Controlled, Double-Blind Parallel Trial.

Randomized clinical trial evaluating the effect of acetazolamide on pulmonary artery pressure in women compared to men travelling to 3600 m.

Study Overview

• Status: Completed
• Conditions: High Altitude
• Intervention / Treatment: Drug: Acetazolamide; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 303
• Phase: Phase 4

Contacts and Locations

Study Locations

• Kyrgyzstan
  • Bishkek
    • Bishkek, Bishkek, Kyrgyzstan, 720040
      • National Center for Cardiology and Internal Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy, non-smoking men and women, age 18-44 years, without any diseases and need of regular medication (including oral contraceptives).
• BMI >18 kg/m2 and <30 kg/m2
• Born, raised and currently living at altitudes <1000 m
• Written informed consent
• Premenopausal women with an eumenorrheic cycle

Exclusion Criteria:

• Other types of contraceptvies (hormonal intrauterine device, vaginal ring, subcutaneous injections or implants, among others)
• Pregnancy or nursing
• Anaemic (haemoglobin concentration <10g/dl)
• Any altitude trip <4 weks before the study
• Allergy to acetazolamide and other sulfonamides

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: WOMEN - PLACEBO oral capsule; Placebo (capsules identically looking as acetazolamide capsules; 1 in the morning, 1 in the evening), orally. Medication starts 24 hours before ascent to 3600 m until the morning after the second night at 3600 m.	Drug: Placebo; Administration of equally looking placebo capsules in the morning and in the evening, starting 24 hours before departure to 3600 m.
Placebo Comparator: MEN - PLACEBO oral capsule; Placebo (capsules identically looking as acetazolamide capsules; 1 in the morning, 1 in the evening), orally. Medication starts 24 hours before ascent to 3600 m until the morning after the second night at 3600 m.	Drug: Placebo; Administration of equally looking placebo capsules in the morning and in the evening, starting 24 hours before departure to 3600 m.
Active Comparator: WOMEN - ACETAZOLAMIDE oral capsule; Acetazolamide 250 mg/day (capsules @125 mg; 1 in the morning, 1 in the evening), orally. Medication starts 24 hours before ascent to 3600 m until the morning after the second night at 3600 m	Drug: Acetazolamide; Administration of 1x125mg acetazolamide in the morning, 1x125mg in the evening, starting 24 hours before departure to 3600 m.
Active Comparator: MEN - ACETAZOLAMIDE oral capsule; Acetazolamide 250 mg/day (capsules @125 mg; 1 in the morning, 1 in the evening), orally. Medication starts 24 hours before ascent to 3600 m until the morning after the second night at 3600 m	Drug: Acetazolamide; Administration of 1x125mg acetazolamide in the morning, 1x125mg in the evening, starting 24 hours before departure to 3600 m.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pulmonary artery Pressure (PAP)	Sex-related difference in the altitude-induced change in RV/RA in mmHg assessed by echocardiography between acetazolamide and placebo group.	Day 2 at 760 m and Day 2 at 3600 m

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung comets	Sex-related difference in the altitude-induced change in ultrasound lung comets assessed by echocardiography between acetazolamide and placebo group.	Day 2 at 760 m and Day 2 at 3600 m
Parameters of right heart function	Sex-related difference in the altitude-induced change in parameters of right heart function assessed by echocardiography between acetazolamide and placebo group.	Day 2 at 760 m and Day 2 at 3600 m

Collaborators and Investigators

• Sponsor: University of Zurich
• Collaborators: University Hospital Heidelberg; National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov; Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques
• Investigators: Study Director: Talant Sooronbaev, Prof. Dr., National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan; Study Chair: Silvia Ulrich, Prof. Dr., University of Zurich

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2024
• Primary Completion (Actual): August 31, 2025
• Study Completion (Actual): August 31, 2025

Study Registration Dates

• First Submitted: July 5, 2024
• First Submitted That Met QC Criteria: July 5, 2024
• First Posted (Actual): July 12, 2024

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Women; Acetazolamide; Prevention; Hypoxia; Echocardiography
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia; Altitude Sickness; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Thiazoles; Azoles; Thiadiazoles; Acetazolamide
• Other Study ID Numbers: HighCycle_PAP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No