Effects of high altitude on sleep breathing in women during their menstrual cycle

HighCycle Study: Effect of High Altitude on Sleep Disordered Breathing in Women Related to Their Menstrual Cycle Phase. A Prospective Cohort Study at 3600 m.

Observational University of Zurich · NCT06498544

This study looks at how different phases of the menstrual cycle affect breathing during sleep in healthy women when they are at high altitudes.

Quick facts

Study typeObservational
Enrollment90 (estimated)
Ages18 Years to 44 Years
SexFemale
SponsorUniversity of Zurich Academic / other
Locations1 site (Bishkek, Bishkek)
Trial IDNCT06498544 on ClinicalTrials.gov

What this trial studies

This observational study investigates how different phases of the menstrual cycle affect sleep-disordered breathing in healthy women when exposed to high altitude conditions at 3600 meters. The study will involve a cohort of women aged 18-44 who are premenopausal and have regular menstrual cycles. Participants will be monitored for changes in their sleep patterns and breathing while at high altitude, providing insights into the relationship between altitude, menstrual cycle phases, and sleep health.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy, non-smoking women aged 18-44 with regular menstrual cycles who live at lower altitudes.

Not a fit: Patients who are pregnant, nursing, or using hormonal contraceptives may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved understanding and management of sleep-disordered breathing in women, particularly in high-altitude environments.

How similar studies have performed: While there is limited research specifically on this topic, studies on sleep-disordered breathing and altitude have shown varying results, indicating that this approach may provide new insights.

Eligibility criteria

Show full inclusion / exclusion criteria
Criteria: Inclusion Criteria:

* Healthy, non-smoking 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, eumenorrheic cycle

Exclusion Criteria:

* Other types of contraceptives (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

Where this trial is running

Bishkek, Bishkek

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Sleep-Disordered BreathingPeriodic breathingHypoxiaPreventionAcetazolamideWomenAltitude
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.