Night-to-Night Variability of Novel Physiological Parameters in Home Sleep Apnea Testing
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Obstructive Apnea, Diagnostic, Sleep Apnea Syndrome (OSAS). Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Switzerland
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Overview
Obstructive sleep apnea (OSA) is usually diagnosed from a single night of home sleep apnea testing using the apnea-hypopnea index (AHI). However, the AHI varies substantially from night to night, undermining diagnostic accuracy, and shows only modest correlation with symptoms. This variability further limits its usefulness for predicting cardiovascular and other complications. Besides the traditional AHI, more robust physiological markers are needed. Several emerging physiological metrics - hypoxic burden, ventilatory burden, heart rate variability, autonomic arousals, and the pulse wave amplitude drop index - capture the physiological impact of OSA more comprehensively and demonstrate stronger associations with cardiovascular risk. Despite this promise, their night-to-night variability has not been studied. A systematic evaluation of both established and novel OSA metrics across nights is essential to identify reliable, stable parameters suitable for clinical routine. This improves diagnostic precision beyond what traditional metrics can provide, enhances patient selection, reduces costs and patient harm, and may improve treatment outcomes.
Primary outcome measures
- Night-to-night variability of apnea-hypopnea index (events per hour of sleep) over 4 nights [Time frame: 4 nights of respiratory polygraphy]
- Night-to-night variability of oxygen desaturation index (events per hour of sleep) over 10 nights [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
- Night-to-night variability of hypoxic burden (minute x percent per hour of sleep) over 10 nights [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
- Night-to-night variability of ventilatory burden over 4 nights [Time frame: 4 nights of respiratory polygraphy]
- Night-to-night variability of heart rate variability over 10 nights [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
- Night-to-night variability of pulse wave amplitude drops (events per hour) over 10 nights [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
Secondary outcome measures (2)
- Identification of factors contributing to and explaining variability [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
- Correlation between physiological parameters from sleep testing and patient-reported outcome measures (PROMs) [Time frame: 4 nights of respiratory polygraphy and 10 nights of oxymetry]
Eligibility criteria
Inclusion criteria
- Patients with suspected or diagnosed sleep-disordered breathing, irrespective of disease severity, as defined by the indications for home sleep apnea testing in the German guidelines \[15\]
- No active treatment during sleep recordings or within preceding two weeks (e.g., mandibular advancement devices, positive airway pressure therapy)
- Written informed consent obtained
Exclusion criteria
- Age <18 years
- Known or suspected neurological sleep disorder (e.g., narcolepsy, parasomnia)
- Known or suspected psychiatric sleep disorder
- Known or suspected central and complex sleep apnea
- Participants who are unable to perform sleep measurements reliably
- Insufficient knowledge of the project language (German)
- Inability to give consent
- Shift workers (with shift work <2 weeks before testing)
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Switzerland · 1 center
- Inselspital University Hospital and University Bern — Bern
Identifiers
NCT: NCT07555119 · 2026-00237