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Study to Assess the Changes in Blood Clotting Factors and Blood Vessel Wall Function in Obstructive Sleep Apnea

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: July 10, 2009
Last Update Posted: October 25, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Kanika Bagai, Vanderbilt University

Obstructive sleep apnea is a condition in which people have decreased breathing during their sleep. Untreated sleep apnea has been linked to increased risk for cardiovascular diseases.

This research study is looking at blood clotting factors and blood vessel function in health volunteers and patients with newly diagnosed or untreated obstructive sleep apnea to better understand the underlying mechanisms for increased cardiovascular risk.

Obstructive Sleep Apnea

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Variability of Fibrinolytic Markers and Endothelial Function in Obstructive Sleep Apnea

Resource links provided by NLM:

Further study details as provided by Kanika Bagai, Vanderbilt University:

Primary Outcome Measures:
  • Comparison of Levels of Mean PAI-1 Activity in Patients With Obstructive Sleep Apnea and Controls. [ Time Frame: at the initial visit ]

Secondary Outcome Measures:
  • Comparison of Endothelial (Blood Vessel) Wall Diameter in Patients With Obstructive Sleep Apnea Versus Controls. [ Time Frame: at initial visit ]

Biospecimen Retention:   Samples With DNA
Blood samples to measure plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (t-PA)levels, endothelial function,fasting lipid profile and glucose levels.

Enrollment: 34
Study Start Date: February 2008
Study Completion Date: April 2012
Primary Completion Date: April 2012 (Final data collection date for primary outcome measure)
Healthy controls
18 years or older with body mass index between 25-45
Obstructive Sleep Apnea Group
Age 18 years or older with body mass index between 25 and 45

Detailed Description:

Cardiovascular disease (CVD), which includes strokes, has been the number one killer in the United States.Each year about 700,000 people experience a new or recurrent stroke, which translates into about one stroke every 45 seconds. Apart from traditional risk factors for stroke such as hypertension, smoking and atrial fibrillation, obstructive sleep apnea is now being increasingly recognized as another important treatable risk factor.

The majority of strokes and myocardial infarctions are due to atherothrombotic events. Impaired fibrinolytic activity increases the propensity for thromboembolic events. Many different candidate molecules have been studied as the cause of a hypercoagulable state. Plasminogen Activator Inhibitor-1 (PAI-1) is the major physiologic inhibitor of the body's fibrinolytic system including the principal serine protease tissue-type plasminogen activator (t-PA). It is therefore poised to be a pivotal regulator of the fibrinolytic system.Recent studies have shown that PAI-1 levels are elevated in patients with obstructive sleep apnea (OSA) and that PAI-1 levels correlate with severity of OSA.

The purpose of this pilot study is twofold:

  • To characterize changes in the blood levels of plasminogen activator inhibitor-1 (PAI-1) and tissue type plasminogen activator ( t-PA) across the 24 hour cycle in patients with obstructive sleep apnea, as compared to normal controls, and to further identify the pattern of changes with varying severity of obstructive sleep apnea, and
  • To study endothelial function in patients with obstructive sleep apnea, as compared to normal controls.

Data gathered from this pilot study will be used to initiate a more comprehensive prospective study exploring the link between OSA, endothelial function, the fibrinolytic system and cardiovascular events. This area can be further explored by prospectively following patients to assess for a reduction in such events with treatment of OSA.


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
We are looking for adults over age 18 years without significnt medical or psychiatric conditions (other than sleep apnea).

Inclusion Criteria:

  • Age 18 years or older.
  • Subjects are able and willing to provide informed consent.
  • Subjects are willing to cooperate with polysomnography and have serial blood draws over a 24-hour period.
  • Evidence for OSA (AHI>5 events/hour) without treatment or suspected OSA based on symptoms in the patient group.
  • Body mass index of 25-45

Exclusion Criteria:

  • History of myocardial infarction, stroke or transient ischemic attack (TIA) or peripheral vascular disease.
  • History of chronic diseases such as diabetes mellitus, uncontrolled hypertension (SBP >160, DBP > 120), renal failure on dialysis, cancer, autoimmune or liver disease.
  • A significant history of medical or psychiatric disease that may impair participation in the trial.
  • Evidence of medical instability (cardiac arrhythmias, congestive heart failure, pulmonary disease) that require an expedited evaluation and treatment of the OSA.
  • History of alcohol, or drug abuse during the one-year-period prior to trial participation.
  • Current use of tobacco products.
  • Current treatment with angiotensin converting enzyme-inhibitors and or chronic use of non-steroidal anti-inflammatory agents.
  • Another primary sleep disorder that requires intervention with medications or cause disrupted sleep.
  • Patients with unusual sleep or wake habits, including shift work.
  • Transmeridian travel in the previous 3 months.
  • Patients with OSA who have already received treatment with CPAP, surgery or oral appliance.
  • Pregnancy; as hormonal changes affect sleep disordered breathing.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00936481

United States, Tennessee
Vanderbilt University Medical Center,Department of Neurology
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
Principal Investigator: Kanika Bagai, M.D Vanderbilt University Medical Center, Nashville, TN
  More Information

Responsible Party: Kanika Bagai, Assistant Professor, Vanderbilt University
ClinicalTrials.gov Identifier: NCT00936481     History of Changes
Other Study ID Numbers: 090265
First Submitted: July 8, 2009
First Posted: July 10, 2009
Results First Submitted: June 12, 2013
Results First Posted: October 25, 2013
Last Update Posted: October 25, 2013
Last Verified: August 2013

Keywords provided by Kanika Bagai, Vanderbilt University:

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