Intrinsic Periodic Pattern of Breathing (PERHYP1)

July 24, 2014 updated by: Pr. Jean Paul RICHALET, Association pour la Recherche en Physiologie de l'Environnement

Study of Periodic Breathing in Healthy Humans

We made a fortuitous observation of periodic breathing in a healthy subject coming to our outpatient mountain medicine consultation at Avicenne hospital in Bobigny (France). During this consultation, subjects perform a hypoxia exercise test, which allows a good prediction of their risk factors for severe high altitude illnesses. Surprisingly, breath-by-breath recording of the ventilation signal showed a periodic breathing pattern, which increased when the subject started to exercise in hypoxic conditions and was maintained during normoxic exercise.

Therefore, our objective was to confirm this observation in a retrospective study led in 82 subjects who passed this test. We tested the hypothesis that subjects with a brisk ventilatory response to hypoxia might show a more pronounced periodic pattern of ventilation, due to a higher gain of the chemoreceptor feedback loop. Then, our objective is to investigate the mechanisms involved in the periodic pattern in healthy subjects, as a function of exercise intensity, altitude intensity, role of peripheral and central chemoreceptors to O2 and CO2. Finally, we want to investigate the possible role of this ventilatory instability in patients with obstructive or central apneas.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

In a preliminary study, among the population coming to the outpatient consultation of mountain medicine at Avicenne hospital in 2012, 82 subjects (38 females and 44 males) were randomly selected and separated in two groups of 41 high and 41 low responders to hypoxia according to the median value of the hypoxic ventilatory response to hypoxia at exercise (HVRe > or < 0.84 L/min/kg) derived from the hypoxic exercise test (inspired fraction of O2: 0.115, exercise intensity of 30% of maximal aerobic power), as previously described.

The hypoxic exercise test consists in 4 successive phases of 3 to 4 minutes each with the following sequence: rest in normoxia (RN), rest in hypoxia (RH), exercise in hypoxia (EH) and exercise in normoxia (EN). Minute ventilation ( E, L.min-1) is measured through a metabograph (Vmax Encore, SensorMedics, Yorba Linda, CA). Pulse O2 saturation (SpO2, %) is measured by transcutaneous oximetry (Nellcor N-595, Nellcor, Pleasanton, CA) on a pre-warmed ear lobe. End tidal PCO2 (PETCO2) is measured by infrared thermopile (Vmax Encore, SensorMedics, Yorba Linda, CA). During the whole test, VE, SpO2 and PETCO2 were recorded breath-by-breath. Continuous blood pressure is measured by a Finapres system. Data are transferred to a computer for further spectrum analysis. A Fast Fourier Transform (FFT) is then applied to the ventilation signal in sequences of 128 points in each phase of the test. This method will allow us to detect the presence of peaks in the frequency domain of the ventilation signal. Two main parameters are derived from the FFT: the frequency in hertz (or period in seconds) of the larger peak and its power estimated as the area under the peak at ± 0.02 Hz around the peak (in L2.s-2).

The main study will be designed in order to unravel the mechanisms and role of these oscillations in ventilation. An overall population of 90 healthy subjects and 30 patients will be included in the study.

Step 1. Effect of exercise intensity.

Step 2. Effect of altitude level.

Step 3. Effect of the stimulation of central chemoreceptors by acetazolamide.

Step 4. Effect of inhibiting the peripheral chemoreceptors by hyperoxia.

Step 5. Effect of inhibiting the peripheral chemoreceptors by hyperoxia and stimulating the central chemoreceptors by hypercapnia.

Step 6. Evaluating the presence of these oscillations in patients with sleep apneas.

Step 7. Evaluating the presence of these oscillations in patients with cardiac failure.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Bobigny, France, 93009
        • Physiology Department

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Healthy subjects Patients with obstructive sleep apneas Patients with cardiac failure

Description

Inclusion Criteria:

  • depending on the group: see definition of groups

Exclusion Criteria:

  • BMI > 30
  • history of severe cardiac arrhythmia
  • pulmonary hypertension
  • history of coronary disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Healthy subjects
male, aged 18-65 moderately trained healthy, no treatment
obstructive sleep apneas
patients with apnea/hypopnea index > 15 BMI < 30 Age < 50 yrs
cardiac failure
NYHA class I to III ejection fraction < 40% age < 65 yrs BMI < 30

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Periodic pattern of ventilation
Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia),
Presence of oscillation in the ventilation signal
The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia),

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Oscillations in heart rate
Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia)
Presence of oscillations in the beat-by-beat ECG signal with a specific peak in the frequency spectrum
The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia)
Oscillations in arterial blood pressure
Time Frame: The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia)
Presence of oscillations in the systolic/diastolic value of instant arterial blood pressure, measured non-invasively.
The measure is made at the end of the 6-min exercise period, only once in each condition (normoxia, hypoxia, hyperoxia, hypercapnia)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Association pour la Recherche en Physiologie de l'Environnement

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2014

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2015

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2015

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 22, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2014

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 28, 2014

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 28, 2014

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2014

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PERHYP1

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