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

Summary

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.

Conditions

• Obstructive Sleep Apnea

Interventions

DEVICE

Continuous positive airway pressure (CPAP)

Continuous positive airway pressure (CPAP) - Horizon LT 8001 Continuous positive airway pressure (CPAP) device.

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.

Sponsors & Collaborators

• Chinese University of Hong Kong

  lead OTHER

Principal Investigators

• David S Hui, MD · Chinese University of Hong Kong

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2005-01-31

Primary Completion

2019-08-06

Completion

2019-08-06

Countries

• Hong Kong

Study Locations