Effect of CPAP on Blood Pressure in Excessively Sleepy Obstructive Sleep Apnea Subtype

Study Overview
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Brief Summary
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The primary objective of this study is to determine the longer-term (6 months) effect of CPAP therapy on change in 24-hour mean blood pressure (24hMBP) in OSA subjects with the excessively sleepy symptom subtype.

Detailed Description
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This is a prospective, non-randomized, observational, two-center study involving newly diagnosed subjects with moderate-severe OSA with the excessively sleepy symptom subtype. Variables of Interest: Change in 24-hour ambulatory BP, change in sitting BP, change in reaction time by psychomotor vigilance test (PVT) Participants will complete questionnaires that pertain to demographics, lifestyle factors, and co-morbidities. The blood samples will be used to determine levels of BP medications and serum creatinine. Measurements will be collected at baseline and at 6-month follow-up visits. Data Analysis Approach: To correct for potential bias in the non-randomized comparison, the investigators will apply a Propensity Score (PS) Design via subclassification. Models to derive the PS values used in this design will include a number of covariates relevant to CPAP adherence, including age, sex, obesity (BMI, neck circumference, waist-to-hip ratio), current smoking, history of hypertension, diabetes mellitus (history, medications), lipid profile, hyperlipidemia (history, medications), family history of premature coronary disease, Charlson comorbidity index, physical activity (IPAQ), diet, OSA severity (AHI, ODI4, T90), sleepiness (Epworth Sleepiness Scale), educational attainment, socioeconomic status (postcode), insomnia symptoms (Insomnia Symptom Questionnaire), anxiety and depression-related symptoms (Patient Health Questionnaire-2), self-efficacy (General self-efficacy scale), and medication adherence (Medication Adherence Report Scale [MARS-5]). Baseline values of outcome measures will also be included in the PS model. After creating the PS design, all analyses are performed accounting for PS subclass as a categorical stratification factor. Evaluations of the CPAP effect on binary outcomes are performed utilizing conditional logistic regression. Similarly, CPAP effects in the context of survival analyses (e.g., Cox Proportional Hazards models) or on continuous outcomes (e.g., linear regression) are assessed by including PS subclass as a categorical covariate in all models.

Official Title
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Effect of CPAP on 24-Hour Blood Pressure in the Excessively Sleepy Obstructive Sleep Apnea Subtype

Conditions
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Obstructive Sleep Apnea

Intervention / Treatment
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* Device: CPAP therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-75 years Moderate-severe OSA (defined as ODI ≥15 events/hour) via Polysomnography (PSG) or Home Sleep Apnea Study (HSAT) done based on clinical grounds Excessively sleepy subtype determined by patient-reported symptoms Willing to accept CPAP therapy An elevated baseline office BP defined as ≥120 or ≥80 mmHg Planned PAP (CPAP or bi-level PAP) treatment by treating provider Exclusion Criteria: Recent changes (within 3 months) to BP medications among those who are on these medications Unable to apply ABPM cuff Current use of CPAP or other OSA treatments Resting, awake SaO2 <90% or use of home oxygen therapy New York Heart Association (NYHA) categories III-IV of heart failure Presence of Cheyne-Stokes Respiration (CSR) in sleep study identified by typical crescendo-decrescendo pattern of respiration with associated apneas and/or hypopneas in the absence of inspiratory flow limitation Predominantly central sleep apnea (AHI≥15 events/hour, with >50% central events [apnea or hypopnea]) Life expectancy <2 years Pregnancy Clinical history of chronic kidney disease (Stage 5) requiring dialysis, or renal transplant Use of wake promoting agents (modafinil, armodafinil, methylphenidate, amphetamine-dextroamphetamine) Self-reported sleep duration less than 5 hours per night on weeknights (work nights) Night shift work, rotating shift work Systolic BP > 180 mmHg

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| OSA subjects with the excessively sleepy symptom subtype treated with CPAP<br>Patients with the excessively sleepy symptom subtype who accept CPAP therapy | Device: CPAP therapy<br>* CPAP treatment of obstructive sleep apnea with the excessively sleepy symptom subtype<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in 24-hour Mean Blood Pressure | 24-hour Mean Blood Pressure obtained from ambulatory blood pressure monitoring (ABPM) | Change from baseline 24-hour Mean Blood Pressure at 6-months after initiation of CPAP therapy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nocturnal Mean BP | Nocturnal Mean Blood Pressure obtained from ambulatory blood pressure monitoring (ABPM) | Change from baseline nocturnal Mean Blood Pressure at 6-months after initiation of CPAP therapy | 
| Reciprocal of Reaction Time | Reciprocal of reaction time obtained by Psychomotor Vigilance Test | Change from baseline reaction time at 6-months after initiation of CPAP therapy | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Excessively Sleepy Symptom Subtype