Cerebrovascular Reactivity in Obstructive Sleep Apnea (OSA) Subjects

NCT01133717 | Unknown

• 1 other identifier: 09-0831-BE
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Obstructive sleep apnea (OSA) is a prevalent sleep breathing disorder in the general population in which recurrent collapse of the upper airway occurs during sleep. OSA is more prevalent in subjects with stroke and is associated with a 3 fold increased risk of stroke. This makes it a serious public health problem. Approximately 50% of subjects with OSA are asymptomatic and are often only detected following investigation for the cause of heart disease or a stroke. In subjects who are treated for OSA many are intolerant or poorly compliant with treatment. Therefore, the identification of those subjects with OSA most at risk of adverse consequences such as stroke is important, so that treatment compliance can be improved. Therfore, the investigators want to determine if compared to subjects without OSA, subjects with OSA have evidence of increased stroke risk by assessment of changes in cerebral blood flow (cerebrovascular reactivity) as measured on Doppler ultrasound of the middle cerebral artery (TCD) and blood oxygen level-dependent magnetic resonance imaging of patterns of cerebral blood flow (BOLD MRI) to two stimuli. These stimuli include increased carbon dioxide concentrations (causes increased cerebral blood flow) and reduced oxygen concentrations (causing decreased cerebral blood flow). In order to deliver these stimuli the investigators will use a special machine (RespiractTM) which allows for the precise control of carbon dioxide and oxygen concentrations in the lungs and blood. The precise control of carbon dioxide and oxygen in conjunction with BOLD MRI has enabled the production of detailed maps of the brain that identify areas of healthy and abnormal blood supply.

Conditions

Sleep Apnea

Keywords

Sleep Apnea; Cerebrovascular Reactivity

Outcome Measures

Primary Outcomes (1)

• Document the diurnal differences in global CVR as measured by TCD, between those with and without OSA

  Between 8pm and 7am approximately

Secondary Outcomes (1)

• Use BOLD MRI to quantify global and regional CVR in various regions and vascular territories of the brain in subjects with OSA.

  one week

Study Arms (2)

Control without Sleep Apnea

Subjects with Sleep Apnea

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Community Population

You may qualify if:

• Subjects referred for sleep studies

You may not qualify if:

• Known cardiac, neurological or major liver or kidney disease -
• Cardioverter/defibrillator metal heart valve or pacemaker
• Vascular stent implanted within 6 weeks
• Severe claustrophobia
• Pregnancy
• Shrapnel or history of ophthalmic foreign body
• Resting oxygen saturation on room air \< 95%
• Insulin-dependent diabetes
• Obstructive or restrictive lung disease such that subject is unable to walk up 2 flights of stairs
• Major depression.

Sponsors & Collaborators

• University Health Network, Toronto: lead

Study Sites (1)

Toronto Gneral Hospital

Toronto, Ontario, M5G 2N2, Canada

RECRUITING

MeSH Terms

Conditions

Sleep Apnea Syndromes

Condition Hierarchy (Ancestors)

Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases

Study Officials

• Clodagh M Ryan

  Toronto General Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clodagh M Ryan, MD

CONTACT

4163404719; clodagh.ryan@uhn.on.ca

Ann battisti, BSc

CONTACT

abattist@uhnres.utoronto.ca

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 20, 2010
• First Posted: May 31, 2010
• Study Start: February 1, 2010
• Primary Completion: February 1, 2015
• Study Completion: April 1, 2015
• Last Updated: December 18, 2014

Record last verified: 2010-10

Locations

CA (1)