Obstructive sleep apnea (OSA) is commonly assessed using the apnea-hypopnea index, although this measure does not fully reflect cardiovascular risk or the physiological impact of the disease. Emerging biomarkers, including sleep apnea-specific hypoxic burden, pulse wave amplitude drop index, and heart rate response, may provide additional information on cardiovascular vulnerability. This prospective multicenter observational study will investigate the association between these biomarkers, measured from the diagnostic sleep study, and adherence to continuous positive airway pressure (CPAP) therapy after three months. Symptoms, quality of life, clinical characteristics, and changes in biomarkers under continuous positive airway pressure will also be evaluated.
This is a prospective, longitudinal, multicenter observational cohort study involving adults with newly diagnosed obstructive sleep apnea for whom continuous positive airway pressure therapy is indicated as part of routine clinical care. At baseline, demographic and clinical characteristics, medical history, current treatments, symptom questionnaires, and results from diagnostic respiratory polygraphy or polysomnography will be collected. Hypoxic burden, pulse wave amplitude drop index, and heart rate response will be calculated from the initial sleep recording. Continuous positive airway pressure will be prescribed according to standard clinical practice. At 12 weeks, with a permitted window of plus or minus four weeks, adherence data will be obtained from the continuous positive airway pressure device. Clinical information and questionnaires will be collected again. Participants requiring a follow-up sleep study as part of routine care may undergo respiratory polygraphy or polysomnography while receiving continuous positive airway pressure, allowing assessment of biomarker changes under treatment. The principal analysis will examine associations between baseline biomarkers and continuous positive airway pressure adherence. Secondary analyses will assess biomarker distributions according to clinical characteristics, associations with symptoms and quality of life, and changes in biomarkers during treatment.
Study Type
OBSERVATIONAL
Enrollment
200
Continuous positive airway pressure prescribed as part of routine clinical care according to applicable clinical recommendations. The study does not assign the treatment or its settings.
Clinique Millenaire
Montpellier, France
RECRUITINGAssociation Between Baseline Hypoxic Burden and CPAP Adherence at 3 Months
Association between hypoxic burden measured during the baseline diagnostic sleep study and mean nightly CPAP use during the 30 days preceding the 3-month visit. CPAP adherence will also be categorized as less than 4 hours per night versus 4 hours or more per night.
Time frame: Baseline to 3 months after CPAP initiation
Distribution of Baseline Sleep Apnea Biomarkers
Distribution of hypoxic burden, pulse wave amplitude drop index, and heart rate response measured or calculated from the baseline respiratory polygraphy or polysomnography. Results will be described according to sex, age, body mass index, medical history, cardiovascular history, and current treatments.
Time frame: BASELINE
Association Between Baseline Heart Rate Response and CPAP Adherence at 3 Months
Association between the heart rate response to respiratory events (delta heart rate) measured during the baseline diagnostic sleep study and mean nightly CPAP use during the 30 days preceding the 3-month visit. CPAP adherence will also be categorized as less than 4 hours per night versus 4 hours or more per night.
Time frame: Baseline to 3 months after CPAP initiation
Association Between Baseline Pulse Wave Amplitude Drop Index and CPAP Adherence at 3 Months
Association between the pulse wave amplitude drop index (PWAD index) measured during the baseline diagnostic sleep study and mean nightly CPAP use during the 30 days preceding the 3-month visit. CPAP adherence will also be categorized as less than 4 hours per night versus 4 hours or more per night.
Time frame: Baseline to 3 months after CPAP initiation
Daytime Sleepiness Assessed by the Epworth Sleepiness Scale
Daytime sleepiness will be assessed using the Epworth Sleepiness Scale at baseline and 3 months after CPAP initiation. The total score ranges from 0 to 24, with higher scores indicating greater daytime sleepiness and therefore a worse outcome. The change in total score between baseline and 3 months will be evaluated.
Time frame: Baseline and 3 months
Health-Related Quality of Life Assessed Using the EuroQol 5-Dimension 5-Level Questionnaire
Health-related quality of life will be assessed using the EuroQol 5-Dimension 5-Level questionnaire (EQ-5D-5L) at baseline and 3 months after CPAP initiation. The EQ-5D-5L evaluates five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has five response levels, ranging from 1 (no problems) to 5 (extreme problems or inability to perform the activity). Responses will be converted into an EQ-5D-5L utility index using the French value set. Index values range from -0.525 to 1, with higher values indicating better health-related quality of life. The change in the utility index between baseline and 3 months will be evaluated.
Time frame: baseline and 3 months
Goal Attainment Assessed by Goal Attainment Scaling
Goal Attainment Scaling score and its change between baseline and the 3-month follow-up visit. Attainment of the participant's individualized treatment goal will be assessed at 3 months using Goal Attainment Scaling (GAS). Goal attainment is rated on a five-point scale ranging from -2 to +2: -2 indicates a much worse outcome than expected, -1 a somewhat worse outcome than expected, 0 the expected level of goal attainment, +1 a somewhat better outcome than expected, and +2 a much better outcome than expected. Higher scores indicate better goal attainment and therefore a better outcome
Time frame: baseline and 3 months
Change in Sleep Apnea-Specific Hypoxic Burden During CPAP Therapy
Sleep apnea-specific hypoxic burden will be calculated from the oxygen desaturation area associated with respiratory events and expressed as percent-minutes per hour (%min/h). The change from the baseline diagnostic sleep study to the sleep study performed during CPAP therapy at 3 months will be evaluated. Higher values indicate a greater hypoxic burden and therefore a worse outcome. This assessment will be performed only in participants undergoing a follow-up sleep study as part of routine care.
Time frame: baseline and 3 months
Change in Pulse Wave Amplitude Drop Index During CPAP Therapy
The pulse wave amplitude drop index will be calculated as the number of pulse wave amplitude drops per hour of sleep or recording. The change from the baseline diagnostic sleep study to the sleep study performed during CPAP therapy at 3 months will be evaluated. Higher values indicate more frequent pulse wave amplitude drops. This assessment will be performed only in participants undergoing a follow-up sleep study as part of routine care.
Time frame: Baseline and 3 months after CPAP initiation
Change in Heart Rate Response to Respiratory Events During CPAP Therapy
Heart rate response will be measured as the mean change in heart rate associated with respiratory events (delta heart rate). The change from the baseline diagnostic sleep study to the sleep study performed during CPAP therapy at 3 months will be evaluated. Higher values indicate a greater heart rate response to respiratory events. This assessment will be performed only in participants undergoing a follow-up sleep study as part of routine care.
Time frame: Baseline and 3 months after CPAP initiation
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