Condition category
Nervous System Diseases
Date applied
07/07/2010
Date assigned
27/07/2010
Last edited
02/12/2013
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Dr Renata Riha

ORCID ID

Contact details

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

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 measures

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

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

http://www.ed.ac.uk

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

Results - basic reporting

Publication summary

2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/23462229
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24210600

Publication citations

  1. 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.

  2. 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.

Additional files

Editorial Notes