Effect of continuous positive airway pressure (CPAP) therapy on arterial stiffness in patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS)

ISRCTN	ISRCTN48783995
DOI	https://doi.org/10.1186/ISRCTN48783995
Protocol serial number	PG/06/092/21267
Sponsor	University of Edinburgh (UK)
Funder	British Heart Foundation (BHF) (UK) (ref: PG/06/092/21267)

Submission date: 07/07/2010
Registration date: 27/07/2010
Last edited: 02/12/2013

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nervous System Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Renata Riha
Scientific

Department of Sleep Medicine
Royal Infirmary of Edinburgh
51 Little France Crescent
Edinburgh
EH16 4SA
United Kingdom

Study information

Primary study design	Interventional
Study design	Randomised double blind placebo-controlled crossover trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
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
Study objectives	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(s)	Lothian Local Research Ethics Committee 02, 24/01/2007, ref: 06/S1102/54
Health condition(s) or problem(s) studied	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
Primary outcome measure(s)	Arterial stiffness as measured by PWV/PWA and aortic distensibility as measured by cardiovascular MRI, at timepoints 0, 12 and 24 weeks
Key secondary outcome measure(s)	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
Completion date	04/08/2009

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Upper age limit	65 Years
Sex	All
Target sample size at registration	80
Key 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
Key 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
Date of first enrolment	01/02/2007
Date of final enrolment	04/08/2009

Locations

Countries of recruitment

United Kingdom
Scotland

Study participating centre

Department of Sleep Medicine

Edinburgh
EH16 4SA
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/05/2013		Yes	No
Results article	results	01/12/2013		Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes