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Withdrawn Not applicable Interventional Accepts healthy volunteers

Vascular Pathophysiology in Obstructive Sleep Apnea

ClinicalTrials.gov ID: NCT00214084

Public ClinicalTrials.gov record NCT00214084. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

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Official title

Influence of Xanthine Oxidase Inhibition on Vascular Function in Obstructive Sleep Apnea

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Obstructive sleep apnea (OSA) is a medical problem whose importance is increasing in recognition and awareness. The National Commission on Sleep Disorders estimates that 15 million Americans have OSA, many of whom remain undiagnosed (24). OSA is associated with the development of hypertension and other cardiovascular diseases (1,2). Patients with OSA, like those with congestive heart failure, hypertension, hypercholesterolemia and diabetes, exhibit impaired EDV (25-32). OSA is also associated with impairments in endothelium-dependent cerebral blood flow responses, which may be a risk factor for stroke (33). Impaired EDV is a result of reduced production or inadequate action of nitric oxide. Since EDV worsens with disease progression and improves with disease treatment, it serves as a prognostic marker of vascular function (34-37). In OSA, hypoxia and neurohumoral disturbances increase generation of reactive oxygen species (ROS) that neutralize nitric oxide and impair endothelium-dependent responses (9,10,38). One source of ROS in endothelial cells is the enzyme xanthine oxidase (38). XO is an enzyme present in the vascular endothelium that significantly contributes to generation of ROS in congestive heart failure, hypercholesterolemia and diabetes (13-17). Inhibition of XO improves endothelium-dependent resistance vessel responses in these populations (13-17), but it is unknown if XO significantly contributes to oxidative stress and endothelial dysfunction in OSA. The central hypothesis of this application is that inhibition of XO with allopurinol will reduce oxidative stress and generation of ROS, thereby improving nitric oxide bioavailability and EDV in OSA. Our hypothesis has been formulated on the basis that patients with OSA experience repeated hypoxemia that increases activity of XO and other enzymes, thus increasing the generation of ROS that negatively impact EDV. Hypoxia is detrimental to vascular homeostasis since it increases generation of ROS through direct mechanisms and via activation of XO.

Study identification

NCT ID
NCT00214084
Recruitment status
Withdrawn
Study type
Interventional
Phase
Not applicable
Enrollment
Not listed

Conditions and interventions

Interventions

Drug

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Accepts healthy volunteers

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Not listed
Primary completion
Not listed
Completion
Not listed
Last update posted
Oct 8, 2015

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
University of Wisconsin Madison Wisconsin 53792 —

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00214084, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Oct 8, 2015 · Synced Oct 15, 2026

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