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Sponsored by: |
Chinese University of Hong Kong |
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Information provided by: | Chinese University of Hong Kong |
ClinicalTrials.gov Identifier: | NCT00300872 |
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 apnoea syndrome (OSA) i.e. 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 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-randomised study with a small sample size has shown a significant decrease in 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 OSA patients treated with nasal CPAP, there are nevertheless conflicting data whether 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 BP in OSA patients after 1 month of nasal CPAP therapy while other investigators have shown no such benefit.
This randomized, sham-placebo controlled study aims to assess 1) the effect of nasal CPAP over a period of 3 months on 24 hr BP; and 2) whether any change in BP and plasma VEGF is related to the baseline severity of OSA and CPAP compliance.
Condition | Intervention |
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Obstructive Sleep Apnoea |
Device: CPAP Device: Sham CPAP |
Study Type: | Interventional |
Study Design: | Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Placebo Control, Parallel Assignment, Efficacy Study |
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 Apnoea Syndrome |
Estimated Enrollment: | 140 |
Study Start Date: | January 2005 |
Estimated Study Completion Date: | December 2009 |
Estimated Primary Completion Date: | January 2009 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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1: Active Comparator
CPAP
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Device: CPAP
CPAP
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2: Sham Comparator
Sham CPAP
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Device: Sham CPAP
Sham CPAP
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Ages Eligible for Study: | 20 Years to 80 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Exclusion Criteria:
Contact: David S Hui, MD | 852 26323135 | dschui@cuhk.edu.hk |
Hong Kong, New Territories | |
The Chinese University of Hong Kong | Recruiting |
Shatin, New Territories, Hong Kong | |
Contact: David S Hui, MD 852 26323135 dschui@cuhk.edu.hk |
Principal Investigator: | David S Hui, MD | Chinese University of Hong Kong |
Responsible Party: | The Chinese University of Hong Kong ( Dr. David SC Hui ) |
Study ID Numbers: | Resp/hui/2006/002 |
Study First Received: | March 8, 2006 |
Last Updated: | May 6, 2008 |
ClinicalTrials.gov Identifier: | NCT00300872 |
Health Authority: | Hong Kong: Department of Health |
Signs and Symptoms Sleep Apnea Syndromes Respiratory Tract Diseases Apnea Respiration Disorders Sleep Apnea, Obstructive |
Dyssomnias Sleep Disorders Signs and Symptoms, Respiratory Endothelial Growth Factors Sleep Disorders, Intrinsic |
Growth Substances Physiological Effects of Drugs Nervous System Diseases Pharmacologic Actions |