HighCycle Study: Effect of Acetazolamide on Sleep Disordered Breathing in Women Compared to Men

HighCycle Study: Effect of Acetazolamide on Sleep Disordered Breathing in Women. A Randomized, Placebo-Controlled, Double-Blind Parallel Trial.

Randomized clinical trial evaluating the effect of acetazolamide on sleep disordered breathing in women compared to men travelling to 3600 m.

Study Overview

• Status: Recruiting
• Conditions: Sleep-Disordered Breathing
• Intervention / Treatment: Drug: Acetazolamide; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 270
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Michael Furian, Prof. Dr.; Phone Number: +41794037586; Email: michael.furian@usz.ch
• Study Contact Backup: Name: Talant Sooronbaev, Prof. Dr.; Phone Number: +996772574567; Email: sooronbaev@yahoo.ru

Study Locations

• Kyrgyzstan
  • Bishkek, Kyrgyzstan, 720040
    • Recruiting
    • National Center for Cardiology and Internal Medicine
    • Contact: Talant M Sooronbaev, MD; Phone Number: +996 312 625679; Email: Sooronbaev@yahoo.com
    • Contact: Konrad E Bloch, MD; Phone Number: +44 255 38 28; Email: konrad.bloch@usz.ch

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
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.
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nocturnal oxygen desaturation index (ODI)	Sex-related difference in the altitude-induced change in the ODI (number of ∆SpO2 >3% per hour time in bed measured by pulse oximetry) between acetazolamide and placebo group.	Night 1 at 760 m and Night 1 at 3600 m

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nocturnal oxygen saturation (SpO2)	Sex-related difference in the altitude-induced change in the mean nocturnal oxygen saturation measured by pulse oximetry between acetazolamide and placebo group.	Night 1 at 760 m and Night 1 at 3600 m
Nocturnal oxygen saturation (SpO2)	Sex-related difference in the altitude-induced change in the mean nocturnal oxygen saturation measured by pulse oximetry between acetazolamide and placebo group.	Night 1 at 760 m and Night 2 at 3600 m
Apnea/hypopnea index (AHI)	Sex-related difference in the altitude-induced change in the mean number of apneas/hypopneas per hour between the acetazolamide and placebo group.	Night 1 at 760 m and Night 1 at 3600 m
Apnea/hypopnea index (AHI)	Sex-related difference in the altitude-induced change in the mean number of apneas/hypopneas per hour between the acetazolamide and placebo group.	Night 1 at 760 m and Night 2 at 3600 m
Subjective sleep quality	Sex-related difference in the altitude-induced change in subjective sleep quality assessed by a 100-mm visual analog scale between the acetazolamide and placebo group.	Night 1 at 760 m and Night 1 at 3600 m
Subjective sleep quality	Sex-related difference in the altitude-induced change in subjective sleep quality assessed by a 100-mm visual analog scale between the acetazolamide and placebo group.	Night 1 at 760 m and Night 2 at 3600 m
Nocturnal oxygen desaturation index (ODI)	Sex-related difference in the altitude-induced change in the ODI (number of ∆SpO2 >3% per hour time in bed measured by pulse oximetry) between acetazolamide and placebo group.	Night 1 at 760 m and Night 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 Chair: Michael Furian, Prof. Dr., University of Zurich; Study Director: Talant Sooronbaev, Prof. Dr., National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2024
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 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 13, 2025
• Last Update Submitted That Met QC Criteria: June 10, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Women; Acetazolamide; Sleep disordered breathing; Prevention; Hypoxia; Altitude; Periodic breathing
• Additional Relevant MeSH Terms: Nervous System Diseases; Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Sleep Wake Disorders; Apnea; Sleep Disorders, Intrinsic; Dyssomnias; Respiratory Aspiration; Sleep Apnea Syndromes; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Diuretics; Natriuretic Agents; Anticonvulsants; Carbonic Anhydrase Inhibitors; Acetazolamide
• Other Study ID Numbers: HighCycle_SDB

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