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Effect of Continuous Positive Airway Pressure (CPAP) Therapy on Changes of Blood Pressure Between Day and Night

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01865864
Recruitment Status : Terminated (Difficulty Recruiting subjects)
First Posted : May 31, 2013
Last Update Posted : May 31, 2013
Staten Island University Hospital
Information provided by (Responsible Party):
Suzanne El-Sayegh, Northwell Health

Brief Summary:
to test whether using CPAP can restore the normal pattern of drop of blood pressure during sleep.

Condition or disease
Obstructive Sleep Apnea Diurnal Blood Pressure

Detailed Description:


To investigate the effect of CPAP therapy on the restoration of the normal diurnal blood pressure pattern. Possible improvement of the circadian dipper pattern after CPAP therapy, with or without a decrease in the mean blood pressure, might constitute an additional potential benefit of CPAP therapy in reducing cardiovascular risk in patients with OSA.


Patients diagnosed with OSA at the sleep center will undergo blood pressure monitoring by measuring the blood pressure every half hour during sleep study. Patients with normal circadian BP changes are treated with CPAP as indicated. Patients with non-dipping BP pattern will be approach to join our study. The patients will receive CPAP therapy. The trial period will be 6 weeks. At the end of the trial, the patients from both treatment arms will undergo a second BP monitoring according to our above-mentioned protocol (systolic, diastolic and mean BP) to determine the circadian BP changes. Apnea-Hypopnea index will be calculated to reflect on the compliance with our therapy. Thus, patients could be divided into two study groups according to their objective compliance.

Baseline population characteristics between the placebo group and CPAP group will be noted. These include apnea-hypopnea index (AHI), medications, other co morbidities and other factors that might affect the normal circadian BP dipping pattern including factors affecting the volume status i.e. diabetes, renal failure, uncontrolled diabetes. Any new medications added during the 6 weeks trial period will be noted.


The difference in daytime and nighttime BP pattern will be noted between the treated (CPAP) and the non-compliant groups. The circadian BP variation will be recorded in both groups. Changes in the circadian BP pattern will be assessed on an intention-to-treat basis. The odds ratio, p value and confidence interval will be calculated. Correlation between the dipping/non-dipping pattern with CPAP compliance, severity of OSA and number of antihypertensive drugs will be studied as well

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Study Type : Observational
Actual Enrollment : 2 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Changes In Diurnal Blood Pressure Pattern In Obstructive Sleep Apnea (OSA) Patients After CPAP Therapy
Study Start Date : July 2008
Actual Primary Completion Date : November 2008
Actual Study Completion Date : November 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sleep Apnea

Compliant with CPAP
noncompliant with CPAP

Primary Outcome Measures :
  1. drop of Blood pressure at night [ Time Frame: 6 weeks ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Obstructive sleep apnea patients age over 18 years

Inclusion Criteria:

1. All patients with OSA who don't meet the above mentioned exclusion criteria

Exclusion Criteria:

  1. Patients who have a normal diurnal sleep pattern (i.e. decrease of more than 30% of the systolic BP at night time)
  2. Patients who are on three or more antihypertensives whose blood pressure is not controlled.
  3. Patients previously treated with CPAP therapy within the past 3 months

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01865864

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United States, New York
Heart Tower
Staten Island, New York, United States, 10305
Sponsors and Collaborators
Northwell Health
Staten Island University Hospital
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Principal Investigator: Suzzane El-Sayegh, MD Staten Island University Hospital

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Responsible Party: Suzanne El-Sayegh, M.D., Northwell Health Identifier: NCT01865864     History of Changes
Other Study ID Numbers: 07-057
First Posted: May 31, 2013    Key Record Dates
Last Update Posted: May 31, 2013
Last Verified: May 2013
Keywords provided by Suzanne El-Sayegh, Northwell Health:
diurnal blood pressure
obstructive sleep apnea
24 hour blood pressure monitor
Additional relevant MeSH terms:
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Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases