protocolSection identificationModule nctId: NCT06277115, orgStudyIdInfo id: BASEC Nr. 2020-02002, briefTitle: Acute and Long-term Effects of CPAP in OSA, statusModule overallStatus: RECRUITING, startDateStruct date: 2021-02-01, primaryCompletionDateStruct date: 2024-07, completionDateStruct date: 2024-12, studyFirstPostDateStruct date: 2024-02-26, lastUpdatePostDateStruct date: 2024-02-28, sponsorCollaboratorsModule leadSponsor name: University of Zurich, class: OTHER, descriptionModule briefSummary: Two-phase interventional non-inferiority trial (phase 1: at least 8 weeks of CPAP; phase 2: 2 weeks of CPAP withdrawal) including 32 patients with moderate to severe OSA to compare the physiological consequences of a short-term CPAP withdrawal to the changes in previously untreated OSA. The trial has been designed as a validation of the CPAP-withdrawal model. Baseline in-laboratory sleep studies will be performed prior to CPAP initiation, after 6-8 weeks on CPAP (treatment effect) and following 2 weeks of CPAP therapy withdrawal (withdrawal effect, effect of OSA recurrence)., conditionsModule conditions: Obstructive Sleep Apnea of Adult, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: NA, interventionModel: SINGLE_GROUP, interventionModelDescription: Two-phase intervention: several weeks of CPAP therapy followed by two weeks CPAP therapy withdrawal, primaryPurpose: TREATMENT, maskingInfo masking: NONE, enrollmentInfo count: 32, type: ESTIMATED, armsInterventionsModule interventions name: Continuous positive airway pressure (CPAP), outcomesModule primaryOutcomes measure: Nocturnal systolic blood pressure, primaryOutcomes measure: Epworth Sleepines Scale Score (ESS), secondaryOutcomes measure: 48h, 24h, diurnal and nocturnal systolic and diastolic blood pressure, secondaryOutcomes measure: Office systolic and diastolic blood pressure, secondaryOutcomes measure: 48h, 24h, diurnal, nocturnal and office heart rate, secondaryOutcomes measure: Heart rate variability in the time and frequency domain (CV, RMSSD, pRR50, LF, HF, LF/HF), secondaryOutcomes measure: Blood pressure variability (BPV, systolic and diastolic), secondaryOutcomes measure: Baroreflex sensitivity (BRS), secondaryOutcomes measure: Arterial stiffness, secondaryOutcomes measure: Measures of nocturnal hypoventilation (median and maximal transcutaneous partial pressure of CO2 = tcpCO2), secondaryOutcomes measure: Measures of nocturnal hypoxaemia (mean nocturnal oxygen saturation = ¢SpO2), secondaryOutcomes measure: Measures of nocturnal hypoxaemia (time spent with SpO2 below 90% = t<90), secondaryOutcomes measure: Measures of nocturnal hypoxaemia (hypoxic burden), secondaryOutcomes measure: Measures of OSA severity (apnoea-hypopnoea-index), secondaryOutcomes measure: Measures of OSA severity (oxygen-desaturation index), secondaryOutcomes measure: Sleepiness (Stanford Sleepiness Scale (SSS)), secondaryOutcomes measure: Fatigue (fatigue severity scale (FSS)), secondaryOutcomes measure: Disease-specific quality of life (Functional Outcomes of Sleep Questionnaire (FOSQ)), secondaryOutcomes measure: Superoxide dismutase, secondaryOutcomes measure: Urinary catecholamines, secondaryOutcomes measure: Pulse rise index (>6 beats per minute), secondaryOutcomes measure: Nocturnal oxymetry measures (¢SpO2, t<90, ODI-3%, ODI-4%), eligibilityModule sex: ALL, minimumAge: 18 Years, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule locations facility: University Hospital Zurich, status: RECRUITING, city: Zurich, zip: 8091, country: Switzerland, contacts name: Esther I Schwarz, MD, role: CONTACT, phone: 0041442553828, email: estherirene.schwarz@usz.ch, contacts name: Joël J Herzig, role: CONTACT, email: joel.herzig@usz.ch, geoPoint lat: 47.36667, lon: 8.54999, hasResults: False