HealthyPhase 1NCT00176007
Hypoxia Impairs Endothelial Function in HAPEs
A Phase 1 study testing Hypoxia in people with Healthy, run by Heidelberg University.
Trial summary
Aim of the study is to investigate the function of the systemic vascular endothelium in individuals susceptible to high-altitude pulmonary oedema during normoxia and normobaric hypoxia. Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Hypoxia
- Type of treatment
- Surgery or procedure
- How many people
- Not given
- Where
- No sites listed yet
- Study dates
- Start not givento not given
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy, male volunteers, age: 18-55
- Able and willing to give written informed consent
Who cannot join
- Known condition causing endothelial dysfunction (e.g. diabetes, hyperlipidaemia, arterial hypertension, smoking, hyperhomocysteinaemia)
- Regular medication and/or treatment with drugs within the last 4 weeks (exclusion has to be decided in each case)
- Acute or chronic illness
- Participation in clinical trial/blood donation within 2 month before the study
- Nicotine, drug and/or alcohol abuse.
About this study
Official title: Hypoxia Impairs Systemic Endothelial Function in Individuals Prone to High-Altitude Pulmonary Edema.
Aim of the study is to investigate the function of the systemic vascular endothelium in individuals susceptible to high-altitude pulmonary oedema during normoxia and normobaric hypoxia.
Read the detailed description
Rationale: High-altitude pulmonary edema (HAPE) is characterized by excessive pulmonary vasoconstriction and is associated with decreased concentrations of nitric oxide (NO) in the lung. Objectives: We hypothesized that individuals susceptible to HAPE (HAPE-S) would also have dysfunction of the vascular NO vasodilator pathway during hypoxia in the systemic vasculature. Methods: During normoxia (FI(O(2)) = 0.21) and 4 hours of normobaric hypoxia (FI(O(2)) = 0.12, corresponding to an altitude of 4,500 m above sea level) endothelium-dependent and endothelium-independent vasodilator responses to intraarterial infusion of acetylcholine (ACh) and sodium nitroprusside, respectively, were measured by forearm venous occlusion plethysmography in nine HAPE-S subjects and in nine HAPE-resistant control subjects. Main Results: Pulmonary artery systolic pressure increased from 22 +/- 3 to 33 +/- 6 mm Hg (p < 0.001) during hypoxia in control subjects, and from 25 +/- 4 to 50 +/- 9 mm Hg in HAPE-S subjects (p < 0.001). Despite similar responses during normoxia in both groups, ACh-induced changes in forearm blood flow markedly decreased during hypoxia in HAPE-S subjects (p = 0.01) but not in control subjects. The attenuated vascular response to ACh infusion during hypoxia inversely correlated with increased pulmonary artery systolic pressure (p = 0.04) and decreased plasma nitrite correlated with attenuated ACh-induced vasodilation in HAPE-S subjects (p = 0.02). Conclusions: Hypoxia markedly impairs vascular endothelial function in the systemic circulation in HAPE-S subjects due to a decreased bioavailability of NO. Impairment of the NO pathway could contribute to the enhanced hypoxic pulmonary vasoconstriction that is central to the pathogenesis of HAPE.
- Conditions
- Healthy
- Being tested
- Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HypoxiaProcedure or surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2005 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Early clinical test
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
Sponsor and investigators
- Lead sponsor
- Heidelberg University
- Sponsor type
- University, hospital or other
- Investigators
- Walter E Haefeli, MD, Principal investigator, Heidelberg University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00176007
- Sponsor's protocol ID
- A001
- Status last verified
- Jun 2005
- First submitted
- 10 Sep 2005
- Last updated
- 15 Sep 2005
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2005. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hypoxia Impairs Systemic Endothelial Function in Individuals Prone to High-Altitude Pulmonary Edema.
- ClinicalTrials.gov ID
- NCT00176007
- Acronym / sponsor ID
- A001
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Lead sponsor
- Heidelberg UniversityUniversity, hospital or other
- First posted
- 15 Sep 2005 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Aim of the study is to investigate the function of the systemic vascular endothelium in individuals susceptible to high-altitude pulmonary oedema during normoxia and normobaric hypoxia.
Detailed description
Rationale: High-altitude pulmonary edema (HAPE) is characterized by excessive pulmonary vasoconstriction and is associated with decreased concentrations of nitric oxide (NO) in the lung. Objectives: We hypothesized that individuals susceptible to HAPE (HAPE-S) would also have dysfunction of the vascular NO vasodilator pathway during hypoxia in the systemic vasculature. Methods: During normoxia (FI(O(2)) = 0.21) and 4 hours of normobaric hypoxia (FI(O(2)) = 0.12, corresponding to an altitude of 4,500 m above sea level) endothelium-dependent and endothelium-independent vasodilator responses to intraarterial infusion of acetylcholine (ACh) and sodium nitroprusside, respectively, were measured by forearm venous occlusion plethysmography in nine HAPE-S subjects and in nine HAPE-resistant control subjects. Main Results: Pulmonary artery systolic pressure increased from 22 +/- 3 to 33 +/- 6 mm Hg (p < 0.001) during hypoxia in control subjects, and from 25 +/- 4 to 50 +/- 9 mm Hg in HAPE-S subjects (p < 0.001). Despite similar responses during normoxia in both groups, ACh-induced changes in forearm blood flow markedly decreased during hypoxia in HAPE-S subjects (p = 0.01) but not in control subjects. The attenuated vascular response to ACh infusion during hypoxia inversely correlated with increased pulmonary artery systolic pressure (p = 0.04) and decreased plasma nitrite correlated with attenuated ACh-induced vasodilation in HAPE-S subjects (p = 0.02). Conclusions: Hypoxia markedly impairs vascular endothelial function in the systemic circulation in HAPE-S subjects due to a decreased bioavailability of NO. Impairment of the NO pathway could contribute to the enhanced hypoxic pulmonary vasoconstriction that is central to the pathogenesis of HAPE.
Study design
- Primary purpose
- Early clinical test
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Healthy, male volunteers, age: 18-55
- Able and willing to give written informed consent
Key exclusion criteria (5 listed)
- Known condition causing endothelial dysfunction (e.g. diabetes, hyperlipidaemia, arterial hypertension, smoking, hyperhomocysteinaemia)
- Regular medication and/or treatment with drugs within the last 4 weeks (exclusion has to be decided in each case)
- Acute or chronic illness
- Participation in clinical trial/blood donation within 2 month before the study
- Nicotine, drug and/or alcohol abuse.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypoxia | Procedure or surgery | – |
Primary outcome
Not reported in the source record.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2005.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Walter E Haefeli, MD principal investigator
Heidelberg University
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Hypoxia in people with Healthy, run by Heidelberg University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 Sep 2005. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2005.