Plain English Summary
Background and study aims
Obstructive sleep apnoea (OSA) is a common sleep-related breathing disorder, in which the throat closes repetitively, blocking the flow of air into the lungs when a person is sleeping. The usual treatment for OSA is continuous positive airway pressure (CPAP) which is a small mask that fits over the nose connected to a machine which blows air at a low pressure into the throat, preventing it from collapsing during sleep. Although it may work well, many people find it uncomfortable and cannot use it. Therefore, alternative treatments for OSA are needed. Fluid accumulates in the legs during the day due to gravity and whilst lying down overnight some of the fluid shifts from the legs into the neck. It is possible that increased fluid in the neck increases pressure around the throat, making it more likely to collapse and cause OSA. Compression stockings are knee-length, tight-fitting stockings which are widely used to treat various conditions, such as varicose veins and swollen legs. They work by gently compressing the legs during the day, so that fluid is unable to accumulate in the legs as it would normally. Therefore, overnight, the amount of fluid shifting from the legs towards the neck should be reduced. This may therefore reduce the amount of fluid collecting in the neck and the degree of narrowing of the throat overnight, and reduce the severity of OSA. Smaller previous studies have already shown this to be the case. The main aims of the study are to assess whether wearing compression stockings during the day for two weeks will decrease the severity of OSA and the symptoms of sleepiness associated with it.
Who can participate?
Patients aged 18 to 80 with OSA, who are not already on treatment. Patients with certain medical conditions or taking particular medications will not be allowed to take part in the study.
What does the study involve?
Participants will be randomly allocated to wear compression stockings or not, so that differences between the two groups can be compared. Participants in the compression stockings group will wear them every day for two weeks but patients in the other (control) group will not need to do anything. Participants will attend a sleep study session at the beginning and end of the two weeks. At the same time, measurements of leg and neck fluid and throat size will be taken, along with a test of alertness and questionnaires on sleepiness and activity levels.
What are the possible benefits and risks of participating?
Compression stockings are very safe and wearing them is not associated with any risks. Participants in the compression stockings group may feel better if their OSA improves.
Where is the study run from?
The Toronto Rehabilitation Institute Sleep Laboratory.
When is the study starting and how long is it expected to run for?
We will be recruiting from June 2012 for approximately 18 months and we plan to recruit 46 patients.
Who is funding the study?
The project is funded by a grant from the Canadian Institutes of Health Research.
Who is the main contact?
Dr Douglas Bradley
douglas.bradley@utoronto.ca
Trial website
Contact information
Type
Scientific
Primary contact
Dr Douglas Bradley
ORCID ID
Contact details
Sleep Laboratory
12th Floor
Toronto Rehabilitation Institute
550 University Avenue
Toronto
M5G 2A2
Canada
+1 (0)416 597 3422 ext 3078
douglas.bradley@utoronto.ca
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
A randomised controlled trial of the effects of compression stockings on severity and clinical outcomes in obstructive sleep apnoea
Acronym
Study hypothesis
In obstructive sleep apnoea (OSA) patients, daytime application of compression stockings will reduce the apnoea-hypopnoea index in association with reductions in leg fluid volume, reduction in overnight decrease in leg fluid volume, reduction in overnight increases in neck fluid volume and neck circumference and an increase in upper airway cross-sectional area. This will be further associated with improvement in sleepiness, alertness and quality of life.
Ethics approval
University Health Network Rehabilitation Medicine and Science Research Ethics Board, 25/05/2012, ref: approval number 12-018
Study design
Single-centre randomised controlled trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Other
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
Intervention
Compression stockings prescribed to apply pressure of 20-30 mmHg at the ankle worn during waking hours for two weeks.
The control group will not receive any treatment.
Outcomes will be measured at the end of the two weeks.
Intervention type
Other
Phase
Not Applicable
Drug names
Primary outcome measure
Apnoea-hypopnoea index measured at baseline and at the end of two weeks
Secondary outcome measures
Changes in:
1. Overnight change in leg and neck fluid volumes (measured by bioimpedance) and neck and calf circumferences
2. Upper airway cross-sectional area, as measured by acoustic pharyngometry
3. Sleepiness, as measured by Epworth sleepiness score
4. Quality of life, as measured by Functional Outcomes of Sleep Questionnaire-10
5. Alertness, as measured by Psychomotor Vigilance Task
Measured at baseline and at the end of two weeks
Overall trial start date
01/06/2012
Overall trial end date
01/12/2013
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Men and women aged 18 to 80 years with OSA (apnoea-hypopnoea index greater than 10)
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
46
Participant exclusion criteria
1. Venous leg ulcers, history of peripheral vascular disease, heart failure, long-term oxygen therapy, cor pulmonale, major organ transplant, neuromuscular disease, end-stage renal disease on dialysis or adeno-tonsillar hypertrophy
2. Current use of corticosteroids or opiates
3. Treatment for OSA currently or within the last 3 months
4. Current use of compression stockings
Recruitment start date
01/06/2012
Recruitment end date
01/12/2013
Locations
Countries of recruitment
Canada
Trial participating centre
Toronto Rehabilitation Institute
Toronto
M5G 2A2
Canada
Sponsor information
Organisation
Toronto Rehabilitation Institute
Sponsor details
550 University Avenue
Toronto
M5G 2A2
Canada
+1 (0)416 597 3422
TRI-REB@uhn.ca
Sponsor type
Hospital/treatment centre
Website
Funders
Funder type
Government
Funder name
Canadian Institutes of Health Research (CIHR) (Canada)
Alternative name(s)
Instituts de Recherche en Santé du Canada, CIHR, IRSC
Funding Body Type
government organisation
Funding Body Subtype
National government
Location
Canada
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
2015 results in: http://www.ncbi.nlm.nih.gov/pubmed/25620198