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Peripheral Vascular Function in Obstructive Sleep Apnoea

This study has been completed.
Sheffield Hallam University
Information provided by (Responsible Party):
Sheffield Teaching Hospitals NHS Foundation Trust Identifier:
First received: June 8, 2012
Last updated: August 6, 2013
Last verified: August 2013
Peripheral vascular function is impaired in people with obstructive sleep apnoea who are untreated compared with age-, weight- and sex-matched healthy controls.

Obstructive Sleep Apnoea

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Effects of Obstructive Sleep Apnoea and Its Treatment on Macrovascular and Microvascular Function

Resource links provided by NLM:

Further study details as provided by Sheffield Teaching Hospitals NHS Foundation Trust:

Primary Outcome Measures:
  • Flow-mediated dilatation of the brachial artery [ Time Frame: Baseline only ]
    The brachial artery dilator response to a 5-min period of forearm arterial occlusion will be measured using a vascular ultrasound scanner and a 7-MHz linear array probe.

Secondary Outcome Measures:
  • GTN-mediated dilatation of the brachial artery [ Time Frame: Baseline only ]
    The brachial artery vasodilator response to a 400 microgram sublingual dose of glyceryl trinitrate will be measured using vascular ultrasound imaging.

  • Forearm skin blood flow response to 5-min proximal-cuff arterial occlusion [ Time Frame: Baseline only ]
    Proximal arterial occlusion will be performed by inflating a blood pressure cuff placed on the upper arm to 200 mmHg for 5 min. After cuff deflation, the skin blood flow response will be measured using laser Doppler flowmetry.

  • Forearm skin blood flow response to localised heating at 42 degrees C [ Time Frame: Baseline only ]
    A local heating unit on the forearm will be heated from 33 to 42 degrees C at a rate of 1 degree C every 10 s. Temperature will be held at 42 degrees C for 35 min. The increase in skin blood flow will be measured using a laser Doppler flowmetry probe placed in the centre of the local heating unit.

Enrollment: 45
Study Start Date: June 2012
Study Completion Date: June 2013
Primary Completion Date: April 2013 (Final data collection date for primary outcome measure)
Untreated OSA patients
Patients with obstructive sleep apnoea who are untreated
OSA patients highly compliant with CPAP
OSA patients established on CPAP therapy (high compliance, > 80% nightly use for ≥ 4 h per night)
OSA patients poorly compliant with CPAP
OSA patients established on CPAP therapy (poor compliance, 10% < nightly use < 50% or < 4 h per night)
Age and BMI-matched controls
Age and BMI-matched controls without OSA

Detailed Description:
Obstructive sleep apnoea (OSA) is a chronic respiratory disorder associated with endothelial dysfunction, increased sympathetic activation and increased cardiovascular risk. The standard treatment paradigm is continuous positive airway pressure (CPAP), however, patient adherence to CPAP is variable. It is unclear to what extent that poor adherence to CPAP therapy augments vascular endothelial function and reduces cardiovascular risk compared to excellent adherence. The main aim of this research is to investigate vascular endothelial function in OSA patients who are poorly-adherent to CPAP therapy. Nitric oxide (NO)-mediated, endothelium-dependent macrovascular and microvascular function (by brachial artery flow-mediated dilatation and forearm cutaneous thermal hyperaemia, respectively) and generalised microvascular function (by post-occlusion reactive hyperaemia) will be assessed in three obese OSA patient populations (high-adherence (n=20); low adherence (n=20); and, untreated (n=20)) and age-/BMI-matched OSA-free controls. We will also assess body composition, cardiovascular risk, lipid status and functional capacity. This research will evaluate treatment efficacy in patients who are poorly-adherent to CPAP treatment and could identify whether an alternative approach to their care should be explored.

Ages Eligible for Study:   18 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Patients and controls living in and around Sheffield, UK

Inclusion Criteria:

  • Obstructive sleep apnoea diagnosed using overnight polysomnography
  • Age 18-90 years

Exclusion Criteria:

  • Unable to perform the tests involved in the study
  • Unable to provide written informed consent
  Contacts and Locations
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Please refer to this study by its identifier: NCT01619748

United Kingdom
Centre for Sport and Exercise Science, Sheffield Hallam University
Sheffield, South Yorkshire, United Kingdom, S102BP
Sheffield Teaching Hospitals NHS FT
Sheffield, South Yorkshire, United Kingdom
Sponsors and Collaborators
Sheffield Teaching Hospitals NHS Foundation Trust
Sheffield Hallam University
Study Director: Garry A Tew, PhD Sheffield Hallam University
Principal Investigator: James Moss, BSc Sheffield Hallam University
Study Director: Stephen Bianchi, MD Sheffield Teaching Hospitals NHS FT
  More Information

Responsible Party: Sheffield Teaching Hospitals NHS Foundation Trust Identifier: NCT01619748     History of Changes
Other Study ID Numbers: STH-16309
Study First Received: June 8, 2012
Last Updated: August 6, 2013

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on April 26, 2017