Coronary Artery Vasospasm, Hypercapnia, Hypertension, Hypoxia, Left Ventricular Function Systolic Dysfunction, Obesity, Right Ventricular Overload, Sleep Apnea, Obstructive, Sleep Disorders, Ventricular Hypertrophy
Conditions
Brief summary
The purpose of this study is to determine the factors that are associated with improved cardiovascular function with the use of CPAP therapy on subjects diagnosed with moderate to severe obstructive sleep apnea.
Detailed description
We will monitor non-invasively changes in arterial stiffness, cardiac mass, pulmonary pressures, endothelial function, etc. We will also assess the reversibility of these changes after only 5-7 days of not using the CPAP mask. In a subgroup of subjects we will explore changes in coronary flow response after 12 weeks of CPAP use compared with baseline.
Interventions
OTHERClinically prescribed CPAP therapy
CPAP as prescribed by attending physician
Sponsors
University of Wisconsin, Madison
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* subjects naïve of CPAP therapy just recently diagnosed with moderate to severe obstructive sleep apnea (OSA). The degree of OSA is defined by results of a comprehensive polysomnogram requiring an apnea hypopnea index (AHI) \>15 events/hour and Epworth score \>10, or an AHI \>20 events/hour * either sex * any race * between 21-50 years old.
Exclusion criteria
* Systolic blood pressure \>160 mmHg, or diastolic blood pressure \>100 mmHg * Changes in antihypertensive medications in the last 6 weeks * Restless leg syndrome * Average overnight oxygen saturation below 80% * Current use of beta-blockers * History of coronary artery disease * History of Stroke * Atrial fibrillation * Peripheral vascular disease * Suspected cardiac valve abnormality * Ejection fraction \<50% * Type I and type II Diabetes Mellitus (DM) * Asthma or confirmed Chronic Obstructive Pulmonary Disease * Cigarette smoking in the last 6 months * Raynaud's disease * Pregnancy (the normal hormonal changes that occur in pregnancy affect greatly arterial stiffness parameters) If a subject becomes pregnant we will discontinue data collection. * Physically incapable of resting on left lateral decubitus for 40 minutes. * Mastectomy with lymph node removal that might preclude us to monitor blood pressures on both arms
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in endothelium mediated response to brachial artery reactivity test between baseline and 4 and 12 weeks after CPAP therapy | 14 weeks | Ultrasound based brachial artery reactivity tests will be performed at entry before CPAP therapy and at 4, 12 weeks post CPAP use and 5-7 days after CPAP withdrawal |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in arterial stiffness between baseline and after CPAP treatment | 14 weeks | Subjects will undergo pulse wave velocity testing with applanation tonometry. tonometry recordings will be at entry and after 4 and 12 weeks of CPAP use and 5-7- days after withdrawal. |
| Changes in coronary artery flow under a cold pressor test | 13 weeks | A subset of subjects with abnormal endothelial function determined during the baseline scan and good echocardiographic images will be invited to participate on this portion of the test. We will record the response to a cold pressor test (submerging their hand in ice water for 1.5 minutes) on left anterior descending coronary artery velocities with transthoracic echocardiography at baseline and after 12 weeks of CPAP therapy. |
Countries
United States
Outcome results
None listed