ClinicalTrials.gov record NCT05489575

CPAP for the Treatment of Supine Hypertension

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 7, 2026

Hemodynamic Effects of Positive Airway Pressure to Treat Supine Hypertension and Improve Neurogenic Orthostatic Hypotension

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
Age40 years old to 80 years old
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This study tests continuous positive airway pressure (CPAP) in people with autonomic failure who have supine hypertension and neurogenic orthostatic hypotension. Participants spend 3–5 days at the research center for screening and up to two daytime study days and/or up to three overnight study nights. Daytime sessions compare active versus sham CPAP for up to 2 hours; overnight sessions compare active CPAP, sham CPAP, and sleeping with the bed tilted head-up for up to 9 hours.

What it is studying. The trial is testing whether applying CPAP (active versus sham) or sleeping head-up changes systolic blood pressure when lying down (nocturnal supine hypertension) and affects morning orthostatic blood-pressure responses in people with autonomic failure. It measures blood pressure, heart rate, other hemodynamic parameters, urine output, and blood markers before, during, and after the interventions.

What the researchers hope to learn. To learn if CPAP changes daytime and nighttime systolic blood pressure in people with supine hypertension, and to study effects on stroke volume, natriuretic peptide levels, nocturnal urine volume, and morning orthostatic tolerance.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

This study aims to learn about the effects of continuous positive airway pressure (CPAP) on people with autonomic failure and high blood pressure when lying down (supine hypertension) to determine if it can be used to treat their high blood pressure during the night. CPAP (a widely used treatment for sleep apnea) involves using a machine that blows air into a tube connected to a mask covering the nose, or nose and mouth, to apply a low air pressure in the airways. The study includes 3-5 days spent in the Vanderbilt Clinical Research Center (CRC): at least one day of screening tests, followed by up to 3 study days. Subjects may be able to participate in daytime and/or overnight studies. The Daytime study consists of 2 study days: one with active CPAP and one with sham CPAP applied for up to 2 hours. The Overnight study consists of 3 study nights: one with active CPAP, one with sham CPAP, both applied for up to 9 hours and one night sleeping with the bed tilted head-up.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Device
  • Active CPAP
  • Sham CPAP
Other
  • Sleeping in a head-up tilt (HUT) position

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Male and female subjects, age 40-80 years, with autonomic failure including pure autonomic failure, multiple system atrophy and Parkinson disease.
  • Neurogenic orthostatic hypotension, defined as a ≥20-mmHg decrease in systolic blood pressure within 3 minutes of standing associated with impaired autonomic reflexes determined by autonomic testing in the absence of other identifiable causes.
  • Nocturnal supine hypertension (nighttime systolic blood pressure ≥140 mmHg) during the overnight screening for supine hypertension.
  • Patients who are willing and able to provide informed consent

Exclusion criteria

  • Patients with history of recent facial trauma or surgery or intolerance to CPAP or to the CPAP mask.
  • Patients who cannot tolerate the medication withdrawal, defined as those who are unable to stand for at least one minute or those with sustained supine blood pressure ≥180/110 mmHg after the medication withdrawal period.
  • Bedridden patients or those who are unable to stand due to motor impairment or severe orthostatic hypotension.
  • Smokers, patients who are pregnant, or have clinically unstable coronary artery disease, or major cardiovascular or neurological event in the past 6 months; heart failure; and other factors which in the investigator's opinion would prevent the subject from completing the protocol including clinically significant abnormalities in clinical or laboratory testing.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

The study includes up to 5 days spent in the Vanderbilt University Medical Center, at least one day of screening tests, followed by 2 study days and/or 2 study nights. Screening tests include a physical examination and history, routine safety laboratory assessments, and autonomic nervous system testing. Medications for high blood pressure will be held for at least 5 half-lives before studies. Subjects may be able to participate in the daytime and/or the overnight studies. Daytime Study: Eligible participants will be studied on two separate days in random order: one day with a high CPAP level and one day with a low CPAP level. The active CPAP level will be determined during a CPAP titration trial On each study day, participants will be instrumented to measure blood pressure, heart rate, hemodynamic parameters, segmental impedance, and markers of cardiovascular risk. A saline lock or IV catheter will be inserted in one of the arm's veins for blood sample collection. Urine will also be collected during studies. After baseline measurements, active or sham CPAP will then be applied for up to 2 hours. Outcome measurements will be repeated after 1 and 2 hours of CPAP. Overnight Studies: Eligible participants will be studied on three separate nights in random order with a active CPAP, sham CPAP, and sleeping in a head-up tilt position. The active CPAP level will be determined during a CPAP titration trial. On each study night, the intervention (active CPAP, sham CPAP, or head-up tilt position) will be applied for up to 9 hours. Blood pressure, heart rate, hemodynamic parameters, and markers of cardiovascular risk will be assessed throughout the night. Urine will also be collected during this period. On the following morning, participants will have a tilt table test.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants spend several days at the study center for screening and up to two daytime study days and/or three overnight study nights. They will stop blood-pressure medicines beforehand, undergo a CPAP titration to set the active pressure, and then be studied using active CPAP, sham CPAP, or sleeping with the bed tilted head-up (CPAP applied up to 2 hours by day or up to 9 hours at night). Study procedures include continuous blood-pressure and heart-rate monitoring, other noninvasive hemodynamic measures, urine collection, blood draws via an IV or saline lock, and a tilt-table test the morning after an overnight study.

How the study is structured. Randomized, crossover, single-masked interventional study. Each participant receives all assigned study conditions in a random order: daytime—one day with active CPAP and one day with sham CPAP (up to 2 hours each); overnight—three nights in random order with active CPAP, sham CPAP, and sleeping head-up (up to 9 hours each). Measurements are taken before, during, and after each session.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on multiple system atrophy

Clinical trials76 trials listed for multiple system atrophyEvery trial the registry lists for multiple system atrophy, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in multiple system atrophy researchLatest monthly update: September 2026. Includes: Tube feeding. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jun 23, 2022
Primary completion
Mar 1, 2027 (estimated)
Study completion
Aug 31, 2027 (estimated)
Target enrollment
59 participants (estimated)
Last updated on registry
Apr 7, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Vanderbilt University Medical Center
Principal investigator
Italo Biaggioni, Professor of Medicine and Pharmacology
Vanderbilt University Medical Center
Collaborators
  • National Heart, Lung, and Blood Institute (NHLBI)

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

Terms used on this page · explanations by MedicalUpdates.ai

sham
A procedure designed to resemble the real procedure, for example the same visit and equipment, without its active part. It is the procedure equivalent of a placebo.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
5 half-lives
The time it takes for the amount of a drug in the body to fall by half. 'Five half-lives' is often used as the point at which a previous drug has essentially left the body.
baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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