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Effect of Nasal Continuous Positive Airway Pressure (CPAP) Blood Pressure and Vascular Endothelial Growth Factor in Obstructive Sleep Apnea Syndrome

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified June 2011 by Chinese University of Hong Kong.
Recruitment status was:  Recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT00300872
First Posted: March 10, 2006
Last Update Posted: June 23, 2011
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.
Information provided by:
Chinese University of Hong Kong
  Purpose

Sleep-disordered breathing (SDB) briefly means cessation of breathing during sleep at least 5 times per hour. SDB is a common disorder affecting 9 to 24% of the middle-aged and overall 4% of the middle-aged male population suffers from the Obstructive sleep apnea syndrome (OSA) i.e. Sleep-disordered breathing (SDB) with associated daytime sleepiness. Several major epidemiological studies have shown that SDB is not only an independent risk factor for hypertension but it is also strongly associated with heart failure and stroke. The mechanism for the linkage between SDB and cardiovascular consequences is not fully determined. Vascular endothelial growth factor (VEGF) is a soluble 34-46 kD angiogenic heparin-binding glycoprotein. This cytokine regulates multiple endothelial cell functions including vascular permeability and vascular tone and some data suggest that it may contribute to the atherosclerotic process. Recent studies have shown increased plasma and serum concentrations of Vascular endothelial growth factor (VEGF) in patients with OSA and there were correlations between VEGF concentrations and the severity of OSA, as indexed by the minimum oxygen saturation level and the frequency of the upper airway obstruction per hour of sleep. A recent non-randomized study with a small sample size has shown a significant decrease in Vascular endothelial growth factor (VEGF) concentrations in patients in whom nocturnal hypoxia improved after 1 year of nasal continuous positive airway pressure (CPAP) therapy.

Despite robust evidence showing improvement of symptoms, cognitive function and quality of life in obstructive sleep apnea (OSA) patients treated with nasal CPAP, there are nevertheless conflicting data whether Continuous positive airway pressure (CPAP) can reduce daytime blood pressure (BP) in patients with OSA. Two randomized placebo controlled studies have shown reduction of 24-hr systolic and diastolic blood pressure (BP) in obstructive sleep apnea (OSA) patients after 1 month of nasal continuous positive airway pressure (CPAP) therapy while other investigators have shown no such benefit.

This randomized, sham-placebo controlled study aims to assess 1) the effect of nasal continuous positive airway pressure (CPAP) over a period of 3 months on 24 hr blood pressure (BP); and 2) whether any change in BP and plasma Vascular endothelial growth factor (VEGF) is related to the baseline severity of obstructive sleep apnea (OSA) and continuous positive airway pressure (CPAP) compliance.


Condition Intervention
Obstructive Sleep Apnea Device: Continuous positive airway pressure (CPAP) Device: Sham Continuous positive airway pressure (CPAP)

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized, Placebo-controlled Study of the Medium-term Effect of Nasal CPAP on 24 Hour Blood Pressure and Vascular Endothelial Growth Factor in Obstructive Sleep Apnea Syndrome

Resource links provided by NLM:


Further study details as provided by Chinese University of Hong Kong:

Primary Outcome Measures:
  • Change in 24 hr mean blood pressure at 3 months [ Time Frame: baseline and 3 months ]

Secondary Outcome Measures:
  • Changes in systolic and diastolic blood pressure, changes in mean blood pressure awake and asleep, change in plasma Vascular endothelia growth factor (VEGF) at 3 months [ Time Frame: baseline and 3 months ]
  • Whether any change in blood pressure or vascular endothelial growth factor (VEGF) is related to the baseline severity of obstructive sleep apnea (OSA) and continuous positive airway pressure (CPAP) compliance over 3 months [ Time Frame: baseline and 3 months ]
  • Epworth Sleepiness Scale (ESS) and Calgary Sleep Apnea Quality of Life Index (SAQLI) at 1 month and 3 months. [ Time Frame: baseline and 3 months ]

Estimated Enrollment: 140
Study Start Date: January 2005
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: January 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1
Continuous positive airway pressure (CPAP)
Device: Continuous positive airway pressure (CPAP)
Continuous positive airway pressure (CPAP) - Horizon LT 8001 Continuous positive airway pressure (CPAP) device.
Sham Comparator: 2
Sham Continuous positive airway pressure (CPAP)
Device: Sham Continuous positive airway pressure (CPAP)
Sham Continuous positive airway pressure (CPAP) - Continuous positive airway pressure (CPAP) units set to the lowest pressure (4 cm of water pressure) and 6 extra 4mm holes will be inserted in the collar of the main tubing at the end of the mask to allow air escape and to prevent carbon dioxide rebreathing.

  Show Detailed Description

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Age 20 to 80 yrs
  • Apnea hypopnea index (AHI) > 10/hr on Polysomnograph (PSG) with symptoms of obstructive sleep apnea (OSA) as described previously
  • Epworth Sleepiness Scale (ESS) >10
  • Patients with hypertension will still be eligible to enter and continue the study as long as there is no alteration of anti-hypertensive medications during the study period

Exclusion Criteria:

  • Patients having problems staying awake during driving, shift work
  • Recent myocardial infarction
  • Unstable angina
  • Underlying malignancy
  Contacts and Locations
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 ClinicalTrials.gov identifier (NCT number): NCT00300872


Contacts
Contact: David S Hui, MD 852 26323135 dschui@cuhk.edu.hk

Locations
Hong Kong
The Chinese University of Hong Kong Recruiting
Shatin, New Territories, Hong Kong
Contact: David S Hui, MD    852 26323135    dschui@cuhk.edu.hk   
Sponsors and Collaborators
Chinese University of Hong Kong
Investigators
Principal Investigator: David S Hui, MD Chinese University of Hong Kong
  More Information

Responsible Party: Dr. David SC Hui, The Chinese University of Hong Kong
ClinicalTrials.gov Identifier: NCT00300872     History of Changes
Other Study ID Numbers: Resp/hui/2006/002
First Submitted: March 8, 2006
First Posted: March 10, 2006
Last Update Posted: June 23, 2011
Last Verified: June 2011

Additional relevant MeSH terms:
Apnea
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Dyssomnias
Sleep Wake Disorders
Nervous System Diseases
Mitogens
Endothelial Growth Factors
Mitosis Modulators
Molecular Mechanisms of Pharmacological Action
Growth Substances
Physiological Effects of Drugs


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