Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
PG/06/092/21267
Study information
Scientific title
Aortic distensibility in obstructive sleep apnoea/hypopnoea syndrome (OSAHS) using cardiovascular magnetic resonance imaging and and pulse wave analysis: effect of continuous positive airway pressure (CPAP) therapy
Acronym
Study hypothesis
Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) affects 1 - 4 % of the middle-aged population causing excessive daytime sleepiness. A greater proportion of the population will exhibit sleep disordered breathing, but will not complain of excessive daytime sleepiness. OSAHS is associated with a significantly increased risk of cardiovascular disease and hypertension. The causes of this are likely to be multifactorial and may include repeated oxygen desaturations or factors associated with the excessive daytime sleepiness. Postulated mechanisms for this increased risk include increased arterial stiffness and endothelial dysfunction, which can be measured non-invasively using applanation tonometry (pulse wave velocity and analysis) and cardiovascular magnetic resonance imaging (MRI). Continuous positive airway pressure (CPAP) therapy is an established treatment for OSAHS and is useful in reducing symptoms, it has also been shown to reduce blood pressure in sleepy patients with OSAHS.
This study aims to measure the effect that CPAP therapy has upon arterial stiffness and endothelial function in patients with OSAHS. By studying patients with varying degrees of OSAHS, both in terms of nocturnal oxygen desaturation and levels of daytime sleepiness, but without known cardiovascular disease we hope to further examine the factors that are important in determining arterial stiffness and endothelial dysfunction in these patients.
Ethics approval
Lothian Local Research Ethics Committee 02, 24/01/2007, ref: 06/S1102/54
Study design
Randomised double blind placebo-controlled crossover trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Hospitals
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Condition
Obstructive sleep apnoea/hypopnoea syndrome (OSAHS)
Intervention
Patients meeting the inclusion criteria will be recruited from the Department of Sleep Medicine. This is a randomised controlled crossover trial with 12 weeks in each limb. The active treatment limb consists of CPAP set to provide optimal pressures for treatment and the placebo limb utilises sham CPAP set to provide a sub-optimal pressure. At baseline and after each limb of the study patients will undergo the following measurements:
1. Pulse wave velocity (PWV) and pulse wave analysis (PWA) - before and after administration of GTN and salbutamol
2. Cardiovascular MRI of aorta
3. Blood pressure recording
4. Epworth Sleepiness Score
Control subjects will undergo the above investigations once.
Patients spent approximately 12 weeks in each limb; total duration of treatment is therefore approximately 24 weeks in total for intervention group. Control subjects were assessed once and there was no further follow up after this.
Intervention type
Other
Phase
Not Applicable
Drug names
Primary outcome measure
Arterial stiffness as measured by PWV/PWA and aortic distensibility as measured by cardiovascular MRI, at timepoints 0, 12 and 24 weeks
Secondary outcome measures
Measured at timepoints 0, 12 and 24 weeks:
1. Endothelial function as measured by pulse wave analysis (before and after administration of GTN and salbutamol)
2. Blood pressure changes
Overall trial start date
01/02/2007
Overall trial end date
04/08/2009
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Both:
1. Males and females aged 18 - 65 years
Patients:
2. Apnoea Hypopnoea Index (AHI) greater than or equal to 15 at polysomnography
3. CPAP naive
4. Ability to give written informed consent
Control subjects:
5. AHI less than or equal to 10 at polysomnography
6. Epworth Sleepiness Score (ESS) less than 11
7. Ability to give written informed consent
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
80 (including 60 patients with varying severity of disease and 20 controls)
Participant exclusion criteria
1. Inability to give written informed consent
2. Known cardiovascular disease or diabetes
3. History of respiratory failure
4. Medications affecting blood pressure
5. Reported sleepiness when driving or those who drive for a living
6. Claustrophobia precluding magnetic resonance imaging (MRI) scanning
7. Implanted/foreign bodies precluding MRI scanning
Recruitment start date
01/02/2007
Recruitment end date
04/08/2009
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Department of Sleep Medicine
Edinburgh
EH16 4SA
United Kingdom
Sponsor information
Organisation
University of Edinburgh (UK)
Sponsor details
Queen's Medical Research Institute
47 Little France Crescent
Edinburgh
EH16 4TJ
United Kingdom
Sponsor type
University/education
Website
Funders
Funder type
Charity
Funder name
British Heart Foundation (BHF) (UK) (ref: PG/06/092/21267)
Alternative name(s)
BHF
Funding Body Type
private sector organisation
Funding Body Subtype
foundation
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/23462229
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24210600
Publication citations
-
Results
Jones A, Vennelle M, Connell M, McKillop G, Newby DE, Douglas NJ, Riha RL, Arterial stiffness and endothelial function in obstructive sleep apnoea/hypopnoea syndrome., Sleep Med., 2013, 14, 5, 428-432, doi: 10.1016/j.sleep.2013.01.001.
-
Results
Jones A, Vennelle M, Connell M, McKillop G, Newby DE, Douglas NJ, Riha RL, The effect of continuous positive airway pressure therapy on arterial stiffness and endothelial function in obstructive sleep apnea: a randomized controlled trial in patients without cardiovascular disease., Sleep Med., 2013, 14, 12, 1260-1265, doi: 10.1016/j.sleep.2013.08.786.