Acute Mountain SicknessPhase 3NCT00664001
Anti-Oxidant Supplementation for the Prevention of Acute Mountain Sickness
A Phase 3 study testing Anti-oxidant supplementation in people with Acute Mountain Sickness, run by Altitude Physiology Expeditions at 1 site in United Kingdom.
Trial summary
Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Acute Mountain Sickness
- What is being tested?
- Anti-oxidant supplementation
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 83 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Mar 2003to Dec 2003
- Phase
- Phase 3
- 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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants in Apex 2 trial
Who cannot join
- High altitude pulmonary oedema (HAPE)
- Gasto-intestinal illness
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Randomized Double-Blind Placebo-Controlled Trial of Oral Anti-Oxidant Supplementation for the Prevention of Acute Mountain Sickness.
Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Magnetic resonance imaging of HACE patients has demonstrated that the oedema in HACE is of the vasogenic, rather that cytotoxic, type. Thus it is likely that cerebrovascular permeability has an important role in the development of AMS and HACE.
Reactive oxygen species (ROS) have been shown to alter the permeability of the blood-brain barrier in severe ischaemia, causing vasogenic cerebral oedema. Endogenous antioxidant systems may have some capacity to respond to oxidative stress in hypoxia. The plasma concentration of urate, a powerful endogenous antioxidant, rises on acute exposure to high altitude and may play a crucial antioxidant role in systemic hypoxia. This antioxidant prevents free-radical induced cerebral oedema in animal models.
Read more
There are numerous sources of ROS in hypoxia, including the mitochondrial electron transfer chain, haemoglobin (Hb) autoxidation and xanthine oxidase activity. There have been several reports of raised markers of oxidative stress in humans at moderate altitude (<3000m).
Oral antioxidant supplementation with preparations containing vitamins C and E in humans at altitude has been shown to decrease breath pentanes (a marker of oxidative stress), and improve erythrocyte filterability. In a small randomised controlled trial, Bailey and Davies demonstrated a significant reduction in symptoms of AMS in subjects taking an oral antioxidant cocktail.
The antioxidants alpha-lipoic acid, vitamin C and vitamin E act synergistically to provide membrane protection from free radical damage, and may protect against hypoxia-induced vascular leakage. We hypothesised that this combination of antioxidants would reduce the severity of acute mountain sickness, and reduce pulmonary artery pressures, in healthy lowlanders acutely exposed to high altitude.
Read the detailed description
Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. By definition, AMS is a benign condition, but it is likely that the same pathology underlies high altitude cerebral oedema (HACE). In contrast, HAPE occurs in the context of pathologically elevated pulmonary artery pressures and uneven distribution of hypoxic pulmonary vasoconstriction across the pulmonary vascular bed.
Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Magnetic resonance imaging of HACE patients has demonstrated that the oedema in HACE is of the vasogenic, rather that cytotoxic, type. Thus it is likely that cerebrovascular permeability has an important role in the development of AMS and HACE.
Reactive oxygen species (ROS) have been shown to alter the permeability of the blood-brain barrier in severe ischaemia, causing vasogenic cerebral oedema. Endogenous antioxidant systems may have some capacity to respond to oxidative stress in hypoxia. The plasma concentration of urate, a powerful endogenous antioxidant, rises on acute exposure to high altitude and may play a crucial antioxidant role in systemic hypoxia. This antioxidant prevents free-radical induced cerebral oedema in animal models.
The pathogenesis of HAPE is understood to have two components: (i) increased pulmonary arterial pressures secondary to hypoxic pulmonary vasoconstriction and; (ii) an increase in endothelial permeability, possibly due to stress rupture of pulmonary capillaries. There is much debate surrounding the cellular mechanisms of hypoxic pulmonary vasoconstriction, but it is likely that ROS have an important role.
There are numerous sources of ROS in hypoxia, including the mitochondrial electron transfer chain, haemoglobin (Hb) autoxidation and xanthine oxidase activity. There have been several reports of raised markers of oxidative stress in humans at moderate altitude (<3000m).
Oral antioxidant supplementation with preparations containing vitamins C and E in humans at altitude has been shown to decrease breath pentanes (a marker of oxidative stress), and improve erythrocyte filterability. In a small randomised controlled trial, Bailey and Davies demonstrated a significant reduction in symptoms of AMS in subjects taking an oral antioxidant cocktail.
The antioxidants alpha-lipoic acid, vitamin C and vitamin E act synergistically to provide membrane protection from free radical damage, and may protect against hypoxia-induced vascular leakage. We hypothesised that this combination of antioxidants would reduce the severity of acute mountain sickness, and reduce pulmonary artery pressures, in healthy lowlanders acutely exposed to high altitude.
- Conditions
- Acute Mountain Sickness
- Being tested
- Anti-oxidant supplementation, Matched placebo for anti-oxidant supplementation
- Medical subject headings
- Altitude Sickness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anti-oxidant supplementationDietary supplement
Daily dose of 1g L-ascorbic acid, 400 IU of alpha-tocopherol acetate, and 600mg of alpha-lipoic acid in sealed capsules as anti-oxidant supplementation.
Matched placebo for anti-oxidant supplementationDietary supplement
Matched placebo for anti-oxidant supplementation
| Study group | Role | What they receive |
|---|---|---|
| Control | Placebo comparator | Placebo tablet Receives: Dietary Supplement: Matched placebo for anti-oxidant supplementation |
| Intervention | Active comparator | Anti-oxidant supplementation Receives: Dietary Supplement: Anti-oxidant supplementation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Acute Mountain Sickness (AMS) as assessed by Lake Louise Consensus symptom score
Measured: Day 2
Secondary outcomes (1)
Pulmonary artery systolic pressure
Measured: Day 6
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Apr 2008 (estimated)
- Study startMar 2003
- Primary completionAug 2003
- Study completionDec 2003
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Acute Mountain SicknessStudies 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 3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 83 participants (actual)
Sponsor and investigators
- Lead sponsor
- Altitude Physiology Expeditions
- Sponsor type
- University, hospital or other
- Collaborators
- University of Edinburgh
- Investigators
- Kenneth Baillie, Principal investigator, Apex Bioscience
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00664001
- Sponsor's protocol ID
- Anti-oxidant
- Status last verified
- Apr 2008
- First submitted
- 7 Apr 2008
- Last updated
- 22 Apr 2008
- Results posted
- No
- Data monitoring committee
- No
Publications
Hall DP, MacCormick IJ, Phythian-Adams AT, Rzechorzek NM, Hope-Jones D, Cosens S, Jackson S, Bates MG, Collier DJ, Hume DA, Freeman T, Thompson AA, Baillie JK. Network analysis reveals distinct clinical syndromes underlying acute mountain sickness. PLoS One. 2014 Jan 22;9(1):e81229. doi: 10.1371/journal.pone.0081229. eCollection 2014.
PubMed 24465370MacCormick IJ, Somner J, Morris DS, MacGillivray TJ, Bourne RR, Huang SS, MacCormick A, Aspinall PA, Baillie JK, Thompson AA, Dhillon B. Retinal vessel tortuosity in response to hypobaric hypoxia. High Alt Med Biol. 2012 Dec;13(4):263-8. doi: 10.1089/ham.2011.1097.
PubMed 23270443Baillie JK, Thompson AA, Irving JB, Bates MG, Sutherland AI, Macnee W, Maxwell SR, Webb DJ. Oral antioxidant supplementation does not prevent acute mountain sickness: double blind, randomized placebo-controlled trial. QJM. 2009 May;102(5):341-8. doi: 10.1093/qjmed/hcp026. Epub 2009 Mar 9.
PubMed 19273551
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2008. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Double-Blind Placebo-Controlled Trial of Oral Anti-Oxidant Supplementation for the Prevention of Acute Mountain Sickness.
- ClinicalTrials.gov ID
- NCT00664001
- Acronym / sponsor ID
- Anti-oxidant
- Conditions
- Acute Mountain Sickness
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 83 participants (actual)
- Lead sponsor
- Altitude Physiology ExpeditionsUniversity, hospital or other
- Collaborators
- University of Edinburgh
- Study start
- Mar 2003
- Primary completion
- Aug 2003 (actual)
- Study completion
- Dec 2003 (actual)
- First posted
- 22 Apr 2008 (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.
Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Magnetic resonance imaging of HACE patients has demonstrated that the oedema in HACE is of the vasogenic, rather that cytotoxic, type. Thus it is likely that cerebrovascular permeability has an important role in the development of AMS and HACE.
Reactive oxygen species (ROS) have been shown to alter the permeability of the blood-brain barrier in severe ischaemia, causing vasogenic cerebral oedema. Endogenous antioxidant systems may have some capacity to respond to oxidative stress in hypoxia. The plasma concentration of urate, a powerful endogenous antioxidant, rises on acute exposure to high altitude and may play a crucial antioxidant role in systemic hypoxia. This antioxidant prevents free-radical induced cerebral oedema in animal models.
There are numerous sources of ROS in hypoxia, including the mitochondrial electron transfer chain, haemoglobin (Hb) autoxidation and xanthine oxidase activity. There have been several reports of raised markers of oxidative stress in humans at moderate altitude (<3000m).
Oral antioxidant supplementation with preparations containing vitamins C and E in humans at altitude has been shown to decrease breath pentanes (a marker of oxidative stress), and improve erythrocyte filterability. In a small randomised controlled trial, Bailey and Davies demonstrated a significant reduction in symptoms of AMS in subjects taking an oral antioxidant cocktail.
The antioxidants alpha-lipoic acid, vitamin C and vitamin E act synergistically to provide membrane protection from free radical damage, and may protect against hypoxia-induced vascular leakage. We hypothesised that this combination of antioxidants would reduce the severity of acute mountain sickness, and reduce pulmonary artery pressures, in healthy lowlanders acutely exposed to high altitude.
Detailed description
Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. By definition, AMS is a benign condition, but it is likely that the same pathology underlies high altitude cerebral oedema (HACE). In contrast, HAPE occurs in the context of pathologically elevated pulmonary artery pressures and uneven distribution of hypoxic pulmonary vasoconstriction across the pulmonary vascular bed.
Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Magnetic resonance imaging of HACE patients has demonstrated that the oedema in HACE is of the vasogenic, rather that cytotoxic, type. Thus it is likely that cerebrovascular permeability has an important role in the development of AMS and HACE.
Reactive oxygen species (ROS) have been shown to alter the permeability of the blood-brain barrier in severe ischaemia, causing vasogenic cerebral oedema. Endogenous antioxidant systems may have some capacity to respond to oxidative stress in hypoxia. The plasma concentration of urate, a powerful endogenous antioxidant, rises on acute exposure to high altitude and may play a crucial antioxidant role in systemic hypoxia. This antioxidant prevents free-radical induced cerebral oedema in animal models.
The pathogenesis of HAPE is understood to have two components: (i) increased pulmonary arterial pressures secondary to hypoxic pulmonary vasoconstriction and; (ii) an increase in endothelial permeability, possibly due to stress rupture of pulmonary capillaries. There is much debate surrounding the cellular mechanisms of hypoxic pulmonary vasoconstriction, but it is likely that ROS have an important role.
There are numerous sources of ROS in hypoxia, including the mitochondrial electron transfer chain, haemoglobin (Hb) autoxidation and xanthine oxidase activity. There have been several reports of raised markers of oxidative stress in humans at moderate altitude (<3000m).
Oral antioxidant supplementation with preparations containing vitamins C and E in humans at altitude has been shown to decrease breath pentanes (a marker of oxidative stress), and improve erythrocyte filterability. In a small randomised controlled trial, Bailey and Davies demonstrated a significant reduction in symptoms of AMS in subjects taking an oral antioxidant cocktail.
The antioxidants alpha-lipoic acid, vitamin C and vitamin E act synergistically to provide membrane protection from free radical damage, and may protect against hypoxia-induced vascular leakage. We hypothesised that this combination of antioxidants would reduce the severity of acute mountain sickness, and reduce pulmonary artery pressures, in healthy lowlanders acutely exposed to high altitude.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control | Placebo comparator | Dietary Supplement: Matched placebo for anti-oxidant supplementationPlacebo tablet |
| Intervention | Active comparator | Dietary Supplement: Anti-oxidant supplementationAnti-oxidant supplementation |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Participants in Apex 2 trial
Key exclusion criteria (2 listed)
- High altitude pulmonary oedema (HAPE)
- Gasto-intestinal illness
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 |
|---|---|---|
| Anti-oxidant supplementationDaily dose of 1g L-ascorbic acid, 400 IU of alpha-tocopherol acetate, and 600mg of alpha-lipoic acid in sealed capsules as anti-oxidant supplementation. | Dietary supplement | Intervention |
| Matched placebo for anti-oxidant supplementationMatched placebo for anti-oxidant supplementation | Dietary supplement | Control |
Primary outcome
Acute Mountain Sickness (AMS) as assessed by Lake Louise Consensus symptom score
Time frame: Day 2
1 secondary outcome
Pulmonary artery systolic pressure
Time frame: Day 6
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 22 Apr 2008.
- Derived from this study: PubMed 24465370Hall DP, MacCormick IJ, Phythian-Adams AT, Rzechorzek NM, Hope-Jones D, Cosens S, Jackson S, Bates MG, Collier DJ, Hume DA, Freeman T, Thompson AA, Baillie JK. Network analysis reveals distinct clinical syndromes underlying acute mountain sickness. PLoS One. 2014 Jan 22;9(1):e81229. doi: 10.1371/journal.pone.0081229. eCollection 2014.
- Derived from this study: PubMed 23270443MacCormick IJ, Somner J, Morris DS, MacGillivray TJ, Bourne RR, Huang SS, MacCormick A, Aspinall PA, Baillie JK, Thompson AA, Dhillon B. Retinal vessel tortuosity in response to hypobaric hypoxia. High Alt Med Biol. 2012 Dec;13(4):263-8. doi: 10.1089/ham.2011.1097.
- Derived from this study: PubMed 19273551Baillie JK, Thompson AA, Irving JB, Bates MG, Sutherland AI, Macnee W, Maxwell SR, Webb DJ. Oral antioxidant supplementation does not prevent acute mountain sickness: double blind, randomized placebo-controlled trial. QJM. 2009 May;102(5):341-8. doi: 10.1093/qjmed/hcp026. Epub 2009 Mar 9.
- Related InfoLink provided by the sponsor.
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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.
Kenneth Baillie principal investigator
Apex Bioscience
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Anti-oxidant supplementation in people with Acute Mountain Sickness, run by Altitude Physiology Expeditions at 1 site in United Kingdom.
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 1 inclusion and 2 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 22 Apr 2008. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. 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. Some participants in this study may receive a placebo. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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.
What does the primary outcome measure?
Acute Mountain Sickness (AMS) as assessed by Lake Louise Consensus symptom score (time frame: Day 2). 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 NCT00664001, which also lists 3 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 22 Apr 2008.