Premature BirthPreAltiNCT04739904
Hypoxia Intolerance in Preterm Individuals
An observational study of Premature Birth and Hypoxia, run by Jozef Stefan Institute at 3 sites in 2 countries.
Trial summary
Reduced Hypoxic Ventilatory Response (HVR) and systemic O2 saturation subsequently leading to blunted aerobic capacity as well as decreased overall physical and cognitive performance are the main physiological challenges faced by prematurely born individuals in hypobaric hypoxia (i.e. during high altitude sojourn). Read more about this study
- Who is it for?
- Ages 18 to 30 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Premature Birth, Hypoxia
- What is being tested?
- Normoxia, Normobaric hypoxia and Hypobaric hypoxia
- How many people
- 36 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 30 Apr 2021to 31 Mar 2022
- Phase
- Observational
- 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 30 years
- Men only
- Healthy volunteers accepted
- Adult
Study population: Prematurely born adults involved in this study must fulfil the following characteristics at birth: gestational age ≤ 32 weeks and gestational weight ≤ 1500g. Conversely, full-term adults involved in this study must fulfil the following characteristics at birth: gestational age of at least 38 weeks.
Who may be able to join
- prematurely born (gestational age: ≤ 32 weeks; gestational weight ≤ 1500g)
- full-term born
- healthy individuals
- male
Who cannot join
- presence of any medical risk factors to exercise and/or exposure to altitude
- presence of any medical condition that would make the protocol unreasonably hazardous for the patient
- smokers
- exposure to altitude above 1000m in the last 2 months
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Slovenia2 sites
Jozef Stefan Institute
Ljubljana, 1000
University of Ljubljana
Ljubljana, 1000
Switzerland1 site
Institute of Sport Sciences of the University of Lausanne
Lausanne, Canton of Vaud, 1015
About this study
Official title: Mechanisms of Hypoxia (in)Tolerance in Prematurely Born Individuals
Reduced Hypoxic Ventilatory Response (HVR) and systemic O2 saturation subsequently leading to blunted aerobic capacity as well as decreased overall physical and cognitive performance are the main physiological challenges faced by prematurely born individuals in hypobaric hypoxia (i.e. during high altitude sojourn). While these phenomena have been described previously, the underlying mechanisms are currently unresolved. Given that the reduction in altitude-performance and its underlying mechanisms are not well understood, it is currently impossible to give evidence-based recommendation for altitude sojourns in this cohort. It is also of note, that even hypobaric hypoxia exposure during long-haul flights might be detrimental to well-being of pre-term born individuals.
The present project aims to comprehensively investigate physiological responses to altitude/hypoxia during rest and exercise in prematurely born, but otherwise healthy adults. Specifically, the investigators aim to elucidate the underlying mechanisms of the altered resting and exercise cardiovascular, respiratory, cerebral and hematological responses to hypoxia in prematurely born individuals. The obtained results from this cohort will be compared to the data from a control groups consisting of healthy, age and aerobic capacity-matched individuals born at full-term. While acute hypoxic effects will be the focus of the project's first phase, the researchers will test the effect of prolonged terrestrial (real) or simulated (normobaric hypoxia) altitude exposures in the second part. This phase will, in addition to the insight into the prolonged altitude acclimatization modulation in prematurely born individuals, also enable the potential differences between the effects of normobaric (simulated) and hypobaric (terrestrial) hypoxia in this cohort to be investigated.
- Conditions
- Premature Birth, Hypoxia
- Being tested
- Normoxia, Normobaric hypoxia, Hypobaric hypoxia
- Keywords
- Acclimatization, Altitude, Preterm birth, Cardiorespiratory, Cerebrovascular, Exercise
- Medical subject headings
- Premature Birth, Hypoxia, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NormoxiaOther
Also called Normoxic condition, Sea level
48 hours experimental protocol conducted at sea level
Normobaric hypoxiaOther
Also called Simulated altitude
24 hours experimental protocol conducted in a normobaric hypoxic facility
Hypobaric hypoxiaOther
Also called Terrestrial altitude
72 hours experimental protocol conducted at terrestrial altitude
| Study group | Role | What they receive |
|---|---|---|
| Preterm born | Premature born but otherwise healthy adults exposed to normoxic, normobaric hypoxic and hypobaric hypoxic interventions. Receives: Other: Normoxia; Other: Normobaric hypoxia; Other: Hypobaric hypoxia | |
| Full-term control | Full-term born healthy adults exposed to normoxic, normobaric hypoxic and hypobaric hypoxic interventions. Receives: Other: Normoxia; Other: Normobaric hypoxia; Other: Hypobaric hypoxia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cerebrovascular reactivity to carbon dioxide (CO2)
Subjects will breath 4 min 3% CO2 and 4 min 6% CO2 separated by 4 min of breathing ambient air. Gas exchange, blood flow in the middle cerebral artery and peripheral oxygen saturation will be continuously recorded by metabolic cart, transcranial doppler, and finger pulse oximeter, respectively.
Measured: 48 hours after exposure to normoxia and hypobaric hypoxia, respectively.
Cognitive function
Cognitive function will be assessed by a computerized psychometric test battery previously used by our research group. These will assess working memory and visuo-motor coordination.
Measured: 24 hours after exposure to normoxia, hypobaric hypoxia, and normobaric hypoxia, respectively
Acute Mountain Sickness (AMS)
AMS will be assessed by Lake Louise scale. AMS will be diagnosed if the Lake Louise score is 3 or higher.
Measured: 8 hours (prior to sleep) and 16 hours (upon waking) after exposure to hypobaric and normobaric hypoxia
Change in respiratory function
Respiratory function will be assessed by spirometry.
Measured: Immediately after exposure to hypobaric and normobaric hypoxia, relative to baseline.
Lung comets
Lung comets will be assessed by counting the number of B-lines present, which will be measured using Doppler ultrasound.
Measured: Every day before and immediately after each exercise bout.
Heart rate response to exercise
Heart rate (HR, bpm) will be continuously monitored during different exercise bouts of variety intensities (moderate and heavy intensities will be used).
Measured: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Respiratory response to exercise
Oxygen consumption (VO2, L/min and mL/min/kg) will be continuously monitored during different exercise bouts of variety intensities (moderate and heavy intensities will be used).
Measured: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Changes in muscular oxygenation during exercise
Muscle oxygenation/deoxygenation will be continuously recorded during each exercise bout by Near Infra-Red Spectroscopy (NIRS) placed on the vastus lateralis. NIRS measure the quantity of oxygenated and deoxygenated haemoglobin and myoglobin (microM) in the investigated areas (vastus lateralis).
Measured: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Changes in cerebral oxygenation during exercise
Brain oxygenation/deoxygenation will be continuously recorded during each exercise bout by Near Infra-Red Spectroscopy (NIRS) placed at the frontal levels. NIRS measure the quantity of oxygenated and deoxygenated haemoglobin (microM) in the investigated areas (prefrontal cortex).
Measured: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Changes in the rate of muscular oxygen consumption (mV̇O2)
Muscle oxygen consumption will be assessed using a previously validated protocol. Briefly, a Near Infra-Red Spectroscopy (NIRS) optode will be placed on the vastus lateralis muscle. Before the protocol, an ischemic calibration will be performed to normalize the NIRS signals by inflating the blood pressure cuff to 250-300 mmHg for a maximum of 5 min. Resting mV̇O2 will be assessed from the decrease in muscle oxygenation which accompanies the arterial occlusion. Four resting measurements will be performed using 10 sec of arterial occlusion. Then, each subject will perform a voluntary knee extension exercise for 15 sec. To measure the recovery of oxygen consumption after exercise, subject will have a series of arterial occlusion as follows: 5 occlusions 5sec on-5sec off, 5 occlusions 5sec on-5sec off, and 8 occlusions 10 sec on-20 sec off.
Measured: Before each exercise bouts.
Acute change in sleep quality
Polysomnography will be used to assess sleep quality. Measurements will include electroencephalography (EEG), electrooculography (EOG), chin and tibial surface electromyography (EMG), electrocardiography (ECG), nasal pressure (nasal pressure cannula), respiratory movements (chest and abdominal belts) as well as capillary oxygenated haemoglobin saturation measurement.
Measured: On the first night in normoxia, normobaric hypoxia and hypobaric hypoxia.
Change in sleep quality after prolonged exposure to hypobaric hypoxia
Polysomnography will be used to assess sleep quality. Measurements will include electroencephalography (EEG), electrooculography (EOG), chin and tibial surface electromyography (EMG), electrocardiography (ECG), nasal pressure (nasal pressure cannula), respiratory movements (chest and abdominal belts) as well as capillary oxygenated haemoglobin saturation measurement.
Measured: On the third night after exposure to terrestrial altitude.
Changes in endothelial capacity to flow-mediated dilation (FMD)
A pneumatic cuff is positioned distal to the ultrasound probe in order to avoid ischemia of the artery studied. Radial artery diameter is measured at rest, during inflation of the distal cuff to suprasystolic pressure (5 min) and for the 5 min following deflation. The subsequent decrease in local blood flow in response to ischemia causes a progressive decrease in the radial artery diameter until a plateau (L-FMC). Upon cuff deflation, the increased blood flow causes radial artery dilatation. L-FMC is calculated as the percentage decrease in arterial diameter in the last 30 s of cuff occlusion as compared with resting diameter. FMD is calculated as the maximum percentage increase in arterial diameter following cuff deflation.
Measured: 24 hours after exposure to normoxia and hypobaric hypoxia.
Changes in orthostatic tolerance
Orthostatic tolerance will be assessed by measuring heart rate variability. This will involve an app-validated 10-min protocol, which will use a chest-band to monitor heart rate changes from 5 minutes of supine position followed by 5 minutes of standing.
Measured: At 6am on every trial day (upon waking).
Changes in oxidative stress markers in the blood
Oxidative stress markers concentration will be measured on collected venous blood sample.
Measured: Blood samples will be collected at 6am (upon waking).
Change in salivary cortisol concentration
Cortisol concentration will be measured on collected saliva samples.
Measured: Saliva samples will be collected at 6am (upon waking).
Change in hydration status
Urine samples will be assessed using urine specific gravity.
Measured: Urine samples will be collected at 6am (upon waking).
Secondary outcomes (1)
Change in cerebral blood flow in the internal carotid artery
Cerebral blood flow in the internal will be assessed every morning by doppler ultrasound.
Measured: Cerebral blood flow will be measured at 10am.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2021
- Study start30 Apr 2021
- Primary completion31 Mar 2022
- Study completion31 Mar 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Premature BirthStudies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Jozef Stefan Institute
- Sponsor type
- University, hospital or other
- Collaborators
- University of Lausanne
- Responsible party
- Principal investigator, Tadej Debevec, Jozef Stefan Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04739904
- Sponsor's protocol ID
- PreAlti
- Acronym
- PreAlti
- Status last verified
- Aug 2024
- First submitted
- 22 Jan 2021
- Last updated
- 15 Aug 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Publications
Manferdelli G, Narang BJ, Bourdillon N, Debevec T, Millet GP. Baroreflex sensitivity is blunted in hypoxia independently of changes in inspired carbon dioxide pressure in prematurely born male adults. Physiol Rep. 2024 Jan;12(1):e15857. doi: 10.14814/phy2.15857.
PubMed 38172085Manferdelli G, Narang BJ, Bourdillon N, Giardini G, Debevec T, Millet GP. Impaired cerebrovascular CO2 reactivity at high altitude in prematurely born adults. J Physiol. 2024 Nov;602(21):5801-5815. doi: 10.1113/JP285048. Epub 2023 Dec 20.
PubMed 38116893Narang BJ, Manferdelli G, Bourdillon N, Millet GP, Debevec T. Ventilatory responses to independent and combined hypoxia, hypercapnia and hypobaria in healthy pre-term-born adults. J Physiol. 2024 Nov;602(21):5943-5958. doi: 10.1113/JP285300. Epub 2023 Oct 5.
PubMed 37796451Manferdelli G, Narang BJ, Bourdillon N, Debevec T, Millet GP. Physiological Responses to Exercise in Hypoxia in Preterm Adults: Convective and Diffusive Limitations in the O 2 Transport. Med Sci Sports Exerc. 2023 Mar 1;55(3):482-496. doi: 10.1249/MSS.0000000000003077. Epub 2022 Oct 26.
PubMed 36459101
Study at a glance
From the registry record, last updated by the sponsor on 15 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mechanisms of Hypoxia (in)Tolerance in Prematurely Born Individuals
- ClinicalTrials.gov ID
- NCT04739904
- Acronym / sponsor ID
- PreAlti / PreAlti
- Conditions
- Premature Birth, Hypoxia
- Keywords
- Acclimatization, Altitude, Preterm birth, Cardiorespiratory, Cerebrovascular, Exercise
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Jozef Stefan InstituteUniversity, hospital or other
- Collaborators
- University of Lausanne
- Study start
- 30 Apr 2021 (actual)
- Primary completion
- 31 Mar 2022 (actual)
- Study completion
- 31 Mar 2022 (actual)
- First posted
- 5 Feb 2021 (actual)
- 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.
Reduced Hypoxic Ventilatory Response (HVR) and systemic O2 saturation subsequently leading to blunted aerobic capacity as well as decreased overall physical and cognitive performance are the main physiological challenges faced by prematurely born individuals in hypobaric hypoxia (i.e. during high altitude sojourn). While these phenomena have been described previously, the underlying mechanisms are currently unresolved. Given that the reduction in altitude-performance and its underlying mechanisms are not well understood, it is currently impossible to give evidence-based recommendation for altitude sojourns in this cohort. It is also of note, that even hypobaric hypoxia exposure during long-haul flights might be detrimental to well-being of pre-term born individuals.
The present project aims to comprehensively investigate physiological responses to altitude/hypoxia during rest and exercise in prematurely born, but otherwise healthy adults. Specifically, the investigators aim to elucidate the underlying mechanisms of the altered resting and exercise cardiovascular, respiratory, cerebral and hematological responses to hypoxia in prematurely born individuals. The obtained results from this cohort will be compared to the data from a control groups consisting of healthy, age and aerobic capacity-matched individuals born at full-term. While acute hypoxic effects will be the focus of the project's first phase, the researchers will test the effect of prolonged terrestrial (real) or simulated (normobaric hypoxia) altitude exposures in the second part. This phase will, in addition to the insight into the prolonged altitude acclimatization modulation in prematurely born individuals, also enable the potential differences between the effects of normobaric (simulated) and hypobaric (terrestrial) hypoxia in this cohort to be investigated.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Preterm born | – | Other: Normoxia, Other: Normobaric hypoxia, Other: Hypobaric hypoxiaPremature born but otherwise healthy adults exposed to normoxic, normobaric hypoxic and hypobaric hypoxic interventions. |
| Full-term control | – | Other: Normoxia, Other: Normobaric hypoxia, Other: Hypobaric hypoxiaFull-term born healthy adults exposed to normoxic, normobaric hypoxic and hypobaric hypoxic interventions. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Prematurely born adults involved in this study must fulfil the following characteristics at birth: gestational age ≤ 32 weeks and gestational weight ≤ 1500g. Conversely, full-term adults involved in this study must fulfil the following characteristics at birth: gestational age of at least 38 weeks.
Key inclusion criteria (4 listed)
- prematurely born (gestational age: ≤ 32 weeks; gestational weight ≤ 1500g)
- full-term born
- healthy individuals
- male
Key exclusion criteria (4 listed)
- presence of any medical risk factors to exercise and/or exposure to altitude
- presence of any medical condition that would make the protocol unreasonably hazardous for the patient
- smokers
- exposure to altitude above 1000m in the last 2 months
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 |
|---|---|---|
| NormoxiaAlso: Normoxic condition, Sea level48 hours experimental protocol conducted at sea level | Other | Full-term control, Preterm born |
| Normobaric hypoxiaAlso: Simulated altitude24 hours experimental protocol conducted in a normobaric hypoxic facility | Other | Full-term control, Preterm born |
| Hypobaric hypoxiaAlso: Terrestrial altitude72 hours experimental protocol conducted at terrestrial altitude | Other | Full-term control, Preterm born |
Primary outcome
Cerebrovascular reactivity to carbon dioxide (CO2)
Time frame: 48 hours after exposure to normoxia and hypobaric hypoxia, respectively.
Subjects will breath 4 min 3% CO2 and 4 min 6% CO2 separated by 4 min of breathing ambient air. Gas exchange, blood flow in the middle cerebral artery and peripheral oxygen saturation will be continuously recorded by metabolic cart, transcranial doppler, and finger pulse oximeter, respectively.
Cognitive function
Time frame: 24 hours after exposure to normoxia, hypobaric hypoxia, and normobaric hypoxia, respectively
Cognitive function will be assessed by a computerized psychometric test battery previously used by our research group. These will assess working memory and visuo-motor coordination.
Acute Mountain Sickness (AMS)
Time frame: 8 hours (prior to sleep) and 16 hours (upon waking) after exposure to hypobaric and normobaric hypoxia
AMS will be assessed by Lake Louise scale. AMS will be diagnosed if the Lake Louise score is 3 or higher.
Change in respiratory function
Time frame: Immediately after exposure to hypobaric and normobaric hypoxia, relative to baseline.
Respiratory function will be assessed by spirometry.
Lung comets
Time frame: Every day before and immediately after each exercise bout.
Lung comets will be assessed by counting the number of B-lines present, which will be measured using Doppler ultrasound.
Heart rate response to exercise
Time frame: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Heart rate (HR, bpm) will be continuously monitored during different exercise bouts of variety intensities (moderate and heavy intensities will be used).
Respiratory response to exercise
Time frame: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Oxygen consumption (VO2, L/min and mL/min/kg) will be continuously monitored during different exercise bouts of variety intensities (moderate and heavy intensities will be used).
Changes in muscular oxygenation during exercise
Time frame: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Muscle oxygenation/deoxygenation will be continuously recorded during each exercise bout by Near Infra-Red Spectroscopy (NIRS) placed on the vastus lateralis. NIRS measure the quantity of oxygenated and deoxygenated haemoglobin and myoglobin (microM) in the investigated areas (vastus lateralis).
Changes in cerebral oxygenation during exercise
Time frame: Every day before exercise, during exercise and at the instant of volitional exhaustion.
Brain oxygenation/deoxygenation will be continuously recorded during each exercise bout by Near Infra-Red Spectroscopy (NIRS) placed at the frontal levels. NIRS measure the quantity of oxygenated and deoxygenated haemoglobin (microM) in the investigated areas (prefrontal cortex).
Changes in the rate of muscular oxygen consumption (mV̇O2)
Time frame: Before each exercise bouts.
Muscle oxygen consumption will be assessed using a previously validated protocol. Briefly, a Near Infra-Red Spectroscopy (NIRS) optode will be placed on the vastus lateralis muscle. Before the protocol, an ischemic calibration will be performed to normalize the NIRS signals by inflating the blood pressure cuff to 250-300 mmHg for a maximum of 5 min. Resting mV̇O2 will be assessed from the decrease in muscle oxygenation which accompanies the arterial occlusion. Four resting measurements will be performed using 10 sec of arterial occlusion. Then, each subject will perform a voluntary knee extension exercise for 15 sec. To measure the recovery of oxygen consumption after exercise, subject will have a series of arterial occlusion as follows: 5 occlusions 5sec on-5sec off, 5 occlusions 5sec on-5sec off, and 8 occlusions 10 sec on-20 sec off.
Acute change in sleep quality
Time frame: On the first night in normoxia, normobaric hypoxia and hypobaric hypoxia.
Polysomnography will be used to assess sleep quality. Measurements will include electroencephalography (EEG), electrooculography (EOG), chin and tibial surface electromyography (EMG), electrocardiography (ECG), nasal pressure (nasal pressure cannula), respiratory movements (chest and abdominal belts) as well as capillary oxygenated haemoglobin saturation measurement.
Change in sleep quality after prolonged exposure to hypobaric hypoxia
Time frame: On the third night after exposure to terrestrial altitude.
Polysomnography will be used to assess sleep quality. Measurements will include electroencephalography (EEG), electrooculography (EOG), chin and tibial surface electromyography (EMG), electrocardiography (ECG), nasal pressure (nasal pressure cannula), respiratory movements (chest and abdominal belts) as well as capillary oxygenated haemoglobin saturation measurement.
Changes in endothelial capacity to flow-mediated dilation (FMD)
Time frame: 24 hours after exposure to normoxia and hypobaric hypoxia.
A pneumatic cuff is positioned distal to the ultrasound probe in order to avoid ischemia of the artery studied. Radial artery diameter is measured at rest, during inflation of the distal cuff to suprasystolic pressure (5 min) and for the 5 min following deflation. The subsequent decrease in local blood flow in response to ischemia causes a progressive decrease in the radial artery diameter until a plateau (L-FMC). Upon cuff deflation, the increased blood flow causes radial artery dilatation. L-FMC is calculated as the percentage decrease in arterial diameter in the last 30 s of cuff occlusion as compared with resting diameter. FMD is calculated as the maximum percentage increase in arterial diameter following cuff deflation.
Changes in orthostatic tolerance
Time frame: At 6am on every trial day (upon waking).
Orthostatic tolerance will be assessed by measuring heart rate variability. This will involve an app-validated 10-min protocol, which will use a chest-band to monitor heart rate changes from 5 minutes of supine position followed by 5 minutes of standing.
Changes in oxidative stress markers in the blood
Time frame: Blood samples will be collected at 6am (upon waking).
Oxidative stress markers concentration will be measured on collected venous blood sample.
Change in salivary cortisol concentration
Time frame: Saliva samples will be collected at 6am (upon waking).
Cortisol concentration will be measured on collected saliva samples.
Change in hydration status
Time frame: Urine samples will be collected at 6am (upon waking).
Urine samples will be assessed using urine specific gravity.
1 secondary outcome
Change in cerebral blood flow in the internal carotid artery
Time frame: Cerebral blood flow will be measured at 10am.
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 Aug 2024.
- Derived from this study: PubMed 38172085Manferdelli G, Narang BJ, Bourdillon N, Debevec T, Millet GP. Baroreflex sensitivity is blunted in hypoxia independently of changes in inspired carbon dioxide pressure in prematurely born male adults. Physiol Rep. 2024 Jan;12(1):e15857. doi: 10.14814/phy2.15857.
- Derived from this study: PubMed 38116893Manferdelli G, Narang BJ, Bourdillon N, Giardini G, Debevec T, Millet GP. Impaired cerebrovascular CO2 reactivity at high altitude in prematurely born adults. J Physiol. 2024 Nov;602(21):5801-5815. doi: 10.1113/JP285048. Epub 2023 Dec 20.
- Derived from this study: PubMed 37796451Narang BJ, Manferdelli G, Bourdillon N, Millet GP, Debevec T. Ventilatory responses to independent and combined hypoxia, hypercapnia and hypobaria in healthy pre-term-born adults. J Physiol. 2024 Nov;602(21):5943-5958. doi: 10.1113/JP285300. Epub 2023 Oct 5.
- Derived from this study: PubMed 36459101Manferdelli G, Narang BJ, Bourdillon N, Debevec T, Millet GP. Physiological Responses to Exercise in Hypoxia in Preterm Adults: Convective and Diffusive Limitations in the O 2 Transport. Med Sci Sports Exerc. 2023 Mar 1;55(3):482-496. doi: 10.1249/MSS.0000000000003077. Epub 2022 Oct 26.
- Individual participant dataSharing planned: Yes
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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.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Premature Birth and Hypoxia, run by Jozef Stefan Institute at 3 sites in 2 countries.
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 4 inclusion and 4 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 Aug 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Slovenia, Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
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.
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.
What does the primary outcome measure?
Cerebrovascular reactivity to carbon dioxide (CO2) (time frame: 48 hours after exposure to normoxia and hypobaric hypoxia, respectively.). The study lists 17 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04739904, which also lists 4 linked publications.
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 Aug 2024.