Long COVID SyndromeNCT07312409
Does Taurine Supplementation Improve Vascular Function and Orthostatic Responses in Long COVID?
An observational study of Long COVID Syndrome, run by York University at 1 site in Canada.
Trial summary
Millions have developed Long COVID (LC), and recent findings show an association between taurine deficiency (an amino acid) and symptoms in LC. Cost-effective and accessible interventions are needed to improve welfare and reduce healthcare costs. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Long COVID Syndrome
- What is being tested?
- Taurine supplementation
- How many people
- 30 participants
- Where
- 1 siteCanada
- Study dates
- 1 Jun 2026to 31 Dec 2027
- How long will I take part?
- 12 Weeks
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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
- No healthy volunteers
- Adult, Older adult
Study population: Men and women aged 18-65 will be recruited who have been diagnosed by a medical professional with Long COVID, which is defined as persistent symptoms for >3 months after a COVID infection. Participants will also need to experience orthostatic intolerance, which is the feeling of dizziness or faintness when standing for a prolonged period. Participants must be able to transport themselves to York University and undergo testing which will take approximately 90 minutes. This includes the ability to undergo a tilt table test for 5 minutes. Therefore, any musculoskeletal problems which prevent upright posture will be excluded. Participants must be able to communicate in English and have the ability to be contacted by email or phone throughout the 12-week period. Current smokers will be excluded. Participants who regularly consume energy drinks that contain taurine (more than once per week) will be excluded.
Who may be able to join
- Participants will have had symptoms of Long COVID post-infection for at least 3 months
Who cannot join
- Inability to undergo tilt table testing for 5 minutes
- Inability to transport selves to York University from their homes
- Inability to speak English, or provide a translator
- Blood clotting disorders
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
York University
Toronto, Ontario, M3J1P3
Heather Edgell, 4167362100 ext. 22927, edgell@yorku.ca
About this study
Millions have developed Long COVID (LC), and recent findings show an association between taurine deficiency (an amino acid) and symptoms in LC. Cost-effective and accessible interventions are needed to improve welfare and reduce healthcare costs. We will investigate the efficacy of 12-weeks of taurine supplementation (self-administered), on vascular function and the cardio/cerebrovascular responses to upright posture. We will measure resting vascular function with an EndoPAT device, resting heart rate variability, and the blood pressure, heart rate, and brain blood flow responses to 5 minutes of head-up tilt before and after weeks of taurine supplementation in LC. We hypothesize that the 12 weeks of supplementation will improve both resting vascular function and the responses to upright tilt. In turn, we hypothesize that symptoms will also improve (as measured by questionnaires).
Read the detailed description
Millions of people have been infected by SARS-CoV-2, or COVID-19, and recent estimates suggest that up to 13% have developed Long COVID [1]. The World Health Organization defines Long COVID as "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation." SARS-CoV-2 is known to use angiotensin converting enzyme 2 (ACE2) to enter cells [2], and ACE2 is located in endothelial cells throughout the cardiovascular system contributing to significant vascular dysfunction [3]. Indeed, vascular function, as measured by flow-mediated dilation (FMD) has been shown to be impaired in otherwise healthy young COVID-19 survivors just 3-4 weeks after infection [4] and persists for at least 6 months in patients who were hospitalized [5]. Recent work has shown a significant correlation between low plasma taurine levels (a naturally occurring amino acid which can help regulate cardiovascular and inflammation) and Long COVID symptoms, and the recovery of taurine levels was associated with fewer adverse events [6]. Notably, twelve weeks of taurine supplementation has been shown to improve blood pressure and vascular function in pre-hypertension [7]. These improvements could, in turn, improve orthostatic tolerance (i.e. lightheadedness while upright, a common symptom in Long COVID). Thus, the purpose of the current proposal is to compare Long COVID patients who are or who are not taking 12-wks taurine supplementation, measuring vascular and orthostatic responses. We hypothesize that those Long COVID patients taking taurine will have better vascular function and orthostatic responses.
Participants: Drawing on the results of Sun et al. (2016) [7] to calculate a sample size, we used an expected change in FMD of 3.2±4.7% with taurine supplementation, resulting in a sample size of 19. To account for potential participant drop-out, we intend to recruit 30 Long COVID patients aged 18-65, including 15 males and 15 females. As this is a pilot project, we will re-evaluate our sample sizes/statistical power when approximately 8 males and 8 females have been completed [8]. Duration and type of symptoms will be recorded using the Symptom Burden Questionnaire for Long COVID. Autonomic function will be assessed with the COMPASS-31 questionnaire and people with symptoms of orthostatic intolerance and/or vasomotor impairment will be recruited. Sex and gender will be self-identified and used as covariates. Any co-morbidities and medication use will be recorded but not excluded.
Study Design: This will be an observational study where half of the participants will already be taking taurine supplements and the other half will not. Each lab assessment will take approximately 60 minutes. Participants will come to York University at baseline and after 12 weeks of time has passed. During the first visit, they will be loaned a Polar heart rate monitor and instructed in its use for home data collection.
- Vascular function: Resting brachial artery FMD will be measured with Duplex ultrasound imaging according to international guidelines [9]. Briefly, five minutes of forearm vascular occlusion using a blood pressure cuff will be applied while brachial artery diameter and flow are measured before, during and for 3 minutes after cuff occlusion. Peak hyperemic brachial arterial velocity will also be measured using Doppler ultrasound immediately after cuff release. Analysis of FMD will be done with edge-detection software (Quipu) to expedite the analysis and reduce measurement error [10]. Concurrently an EndoPAT device will also be used to measure endothelial function.
- Orthostatic responses (during supine rest and 5-min 70o head-up tilt): Cardiovascular and respiratory measures: Heart rate will be measured by ECG, blood pressure/cardiac output will be monitored using a beat-by-beat non-invasive blood pressure device (NexFin), brain blood flow will be assessed with transcranial Doppler ultrasound, and respiratory rate will be assessed using a Respitrace. Heart Rate Variability (HRV): HRV provides an indicator of the autonomic control of heart rate (i.e. parasympathetic and sympathetic balance [11]) and will be analyzed using LabChart Pro 8.0 software in the supine and upright postures. Resting HRV will also be assessed using a Polar heart rate device at home, weekly. The heart rate data will be emailed to the students for analysis.
Analysis plan: Each variable described above will be measured before and after the 12-wks time period. To test the study hypotheses, repeated measures analysis of variance will be used to examine differences over time (SPSS). Sex, gender, and symptom duration will be covariates.
- Conditions
- Long COVID Syndrome
- Being tested
- Taurine supplementation
- Keywords
- Taurine, Vascular, Long COVID, Orthostatic, Cerebrovascular, Heart rate variability
- Medical subject headings
- Post-Acute COVID-19 Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Taurine supplementationDietary supplement
Participants will self-administer 12-wks taurine supplementation
| Study group | Role | What they receive |
|---|---|---|
| Taurine supplementation | Long COVID patients will self-administer 12-wks of taurine supplementation Receives: Dietary Supplement: Taurine supplementation | |
| Time control | Long COVID patients who are not taking taurine supplementation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Orthostatic responses
Measure cardiovascular and cerebrovascular responses to upright tilt using beat to beat blood pressure, ECG, and transcranial Doppler.
Measured: Baseline and 12-weeks
Vascular function
Flow-mediated dilation and EndoPAT response. These techniques concurrently measure endothelial function using the same protocol.
Measured: Baseline and 12-weeks
Secondary outcomes (1)
Heart rate variability
Variability of resting heart rate will be measured in lab using ECG and at home using a polar heart rate strap.
Measured: Over the course of 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2025
- Study start1 Jun 2026
- Primary completion30 Jun 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (11)Papers the sponsor has linked to this study.
- Other trials for Long COVID SyndromeStudies 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
- 30 participants (estimated)
- Target duration
- 12 Weeks
Sponsor and investigators
- Lead sponsor
- York University
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Responsible party
- Principal investigator, Heather Edgell, York University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07312409
- Sponsor's protocol ID
- Edgell Long COVID trial
- Status last verified
- Jun 2026
- First submitted
- 17 Dec 2025
- Last updated
- 5 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: It is against REB protocol to provide individual data, particularly in small sample size studies.
Publications
Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation. 1996 Mar 1;93(5):1043-65. No abstract available.
PubMed 8598068Thijssen DH, Black MA, Pyke KE, Padilla J, Atkinson G, Harris RA, Parker B, Widlansky ME, Tschakovsky ME, Green DJ. Assessment of flow-mediated dilation in humans: a methodological and physiological guideline. Am J Physiol Heart Circ Physiol. 2011 Jan;300(1):H2-12. doi: 10.1152/ajpheart.00471.2010. Epub 2010 Oct 15.
PubMed 20952670Corretti MC, Anderson TJ, Benjamin EJ, Celermajer D, Charbonneau F, Creager MA, Deanfield J, Drexler H, Gerhard-Herman M, Herrington D, Vallance P, Vita J, Vogel R; International Brachial Artery Reactivity Task Force. Guidelines for the ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery: a report of the International Brachial Artery Reactivity Task Force. J Am Coll Cardiol. 2002 Jan 16;39(2):257-65. doi: 10.1016/s0735-1097(01)01746-6.
PubMed 11788217Wittes J, Brittain E. The role of internal pilot studies in increasing the efficiency of clinical trials. Stat Med. 1990 Jan-Feb;9(1-2):65-71; discussion 71-2. doi: 10.1002/sim.4780090113.
PubMed 2345839Sun Q, Wang B, Li Y, Sun F, Li P, Xia W, Zhou X, Li Q, Wang X, Chen J, Zeng X, Zhao Z, He H, Liu D, Zhu Z. Taurine Supplementation Lowers Blood Pressure and Improves Vascular Function in Prehypertension: Randomized, Double-Blind, Placebo-Controlled Study. Hypertension. 2016 Mar;67(3):541-9. doi: 10.1161/HYPERTENSIONAHA.115.06624. Epub 2016 Jan 18.
PubMed 26781281Khoramjoo M, Wang K, Srinivasan K, Gheblawi M, Mandal R, Rousseau S, Wishart D, Prasad V, Richer L, Cheung AM, Oudit GY. Plasma taurine level is linked to symptom burden and clinical outcomes in post-COVID condition. PLoS One. 2024 Jun 5;19(6):e0304522. doi: 10.1371/journal.pone.0304522. eCollection 2024.
PubMed 38837993Oikonomou E, Souvaliotis N, Lampsas S, Siasos G, Poulakou G, Theofilis P, Papaioannou TG, Haidich AB, Tsaousi G, Ntousopoulos V, Sakka V, Charalambous G, Rapti V, Raftopoulou S, Syrigos K, Tsioufis C, Tousoulis D, Vavuranakis M. Endothelial dysfunction in acute and long standing COVID-19: A prospective cohort study. Vascul Pharmacol. 2022 Jun;144:106975. doi: 10.1016/j.vph.2022.106975. Epub 2022 Mar 3.
PubMed 35248780Ratchford SM, Stickford JL, Province VM, Stute N, Augenreich MA, Koontz LK, Bobo LK, Stickford ASL. Vascular alterations among young adults with SARS-CoV-2. Am J Physiol Heart Circ Physiol. 2021 Jan 1;320(1):H404-H410. doi: 10.1152/ajpheart.00897.2020. Epub 2020 Dec 11.
PubMed 33306450Varga Z, Flammer AJ, Steiger P, Haberecker M, Andermatt R, Zinkernagel AS, Mehra MR, Schuepbach RA, Ruschitzka F, Moch H. Endothelial cell infection and endotheliitis in COVID-19. Lancet. 2020 May 2;395(10234):1417-1418. doi: 10.1016/S0140-6736(20)30937-5. Epub 2020 Apr 21. No abstract available.
PubMed 32325026Hoffmann M, Kleine-Weber H, Schroeder S, Kruger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Muller MA, Drosten C, Pohlmann S. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 2020 Apr 16;181(2):271-280.e8. doi: 10.1016/j.cell.2020.02.052. Epub 2020 Mar 5.
PubMed 32142651Ballering AV, van Zon SKR, Olde Hartman TC, Rosmalen JGM; Lifelines Corona Research Initiative. Persistence of somatic symptoms after COVID-19 in the Netherlands: an observational cohort study. Lancet. 2022 Aug 6;400(10350):452-461. doi: 10.1016/S0140-6736(22)01214-4.
PubMed 35934007
Study at a glance
From the registry record, last updated by the sponsor on 5 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does Taurine Supplementation Improve Vascular Function and Orthostatic Responses in Long COVID?
- ClinicalTrials.gov ID
- NCT07312409
- Acronym / sponsor ID
- Edgell Long COVID trial
- Conditions
- Long COVID Syndrome
- Keywords
- Taurine, Vascular, Long COVID, Orthostatic, Cerebrovascular, Heart rate variability
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- York UniversityUniversity, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Study start
- 1 Jun 2026 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 31 Dec 2025 (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.
Millions have developed Long COVID (LC), and recent findings show an association between taurine deficiency (an amino acid) and symptoms in LC. Cost-effective and accessible interventions are needed to improve welfare and reduce healthcare costs. We will investigate the efficacy of 12-weeks of taurine supplementation (self-administered), on vascular function and the cardio/cerebrovascular responses to upright posture. We will measure resting vascular function with an EndoPAT device, resting heart rate variability, and the blood pressure, heart rate, and brain blood flow responses to 5 minutes of head-up tilt before and after weeks of taurine supplementation in LC. We hypothesize that the 12 weeks of supplementation will improve both resting vascular function and the responses to upright tilt. In turn, we hypothesize that symptoms will also improve (as measured by questionnaires).
Detailed description
Millions of people have been infected by SARS-CoV-2, or COVID-19, and recent estimates suggest that up to 13% have developed Long COVID [1]. The World Health Organization defines Long COVID as "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation." SARS-CoV-2 is known to use angiotensin converting enzyme 2 (ACE2) to enter cells [2], and ACE2 is located in endothelial cells throughout the cardiovascular system contributing to significant vascular dysfunction [3]. Indeed, vascular function, as measured by flow-mediated dilation (FMD) has been shown to be impaired in otherwise healthy young COVID-19 survivors just 3-4 weeks after infection [4] and persists for at least 6 months in patients who were hospitalized [5]. Recent work has shown a significant correlation between low plasma taurine levels (a naturally occurring amino acid which can help regulate cardiovascular and inflammation) and Long COVID symptoms, and the recovery of taurine levels was associated with fewer adverse events [6]. Notably, twelve weeks of taurine supplementation has been shown to improve blood pressure and vascular function in pre-hypertension [7]. These improvements could, in turn, improve orthostatic tolerance (i.e. lightheadedness while upright, a common symptom in Long COVID). Thus, the purpose of the current proposal is to compare Long COVID patients who are or who are not taking 12-wks taurine supplementation, measuring vascular and orthostatic responses. We hypothesize that those Long COVID patients taking taurine will have better vascular function and orthostatic responses.
Participants: Drawing on the results of Sun et al. (2016) [7] to calculate a sample size, we used an expected change in FMD of 3.2±4.7% with taurine supplementation, resulting in a sample size of 19. To account for potential participant drop-out, we intend to recruit 30 Long COVID patients aged 18-65, including 15 males and 15 females. As this is a pilot project, we will re-evaluate our sample sizes/statistical power when approximately 8 males and 8 females have been completed [8]. Duration and type of symptoms will be recorded using the Symptom Burden Questionnaire for Long COVID. Autonomic function will be assessed with the COMPASS-31 questionnaire and people with symptoms of orthostatic intolerance and/or vasomotor impairment will be recruited. Sex and gender will be self-identified and used as covariates. Any co-morbidities and medication use will be recorded but not excluded.
Study Design: This will be an observational study where half of the participants will already be taking taurine supplements and the other half will not. Each lab assessment will take approximately 60 minutes. Participants will come to York University at baseline and after 12 weeks of time has passed. During the first visit, they will be loaned a Polar heart rate monitor and instructed in its use for home data collection.
- Vascular function: Resting brachial artery FMD will be measured with Duplex ultrasound imaging according to international guidelines [9]. Briefly, five minutes of forearm vascular occlusion using a blood pressure cuff will be applied while brachial artery diameter and flow are measured before, during and for 3 minutes after cuff occlusion. Peak hyperemic brachial arterial velocity will also be measured using Doppler ultrasound immediately after cuff release. Analysis of FMD will be done with edge-detection software (Quipu) to expedite the analysis and reduce measurement error [10]. Concurrently an EndoPAT device will also be used to measure endothelial function.
- Orthostatic responses (during supine rest and 5-min 70o head-up tilt): Cardiovascular and respiratory measures: Heart rate will be measured by ECG, blood pressure/cardiac output will be monitored using a beat-by-beat non-invasive blood pressure device (NexFin), brain blood flow will be assessed with transcranial Doppler ultrasound, and respiratory rate will be assessed using a Respitrace. Heart Rate Variability (HRV): HRV provides an indicator of the autonomic control of heart rate (i.e. parasympathetic and sympathetic balance [11]) and will be analyzed using LabChart Pro 8.0 software in the supine and upright postures. Resting HRV will also be assessed using a Polar heart rate device at home, weekly. The heart rate data will be emailed to the students for analysis.
Analysis plan: Each variable described above will be measured before and after the 12-wks time period. To test the study hypotheses, repeated measures analysis of variance will be used to examine differences over time (SPSS). Sex, gender, and symptom duration will be covariates.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 12 Weeks
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Taurine supplementation | – | Dietary Supplement: Taurine supplementationLong COVID patients will self-administer 12-wks of taurine supplementation |
| Time control | – | –Long COVID patients who are not taking taurine supplementation |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Men and women aged 18-65 will be recruited who have been diagnosed by a medical professional with Long COVID, which is defined as persistent symptoms for >3 months after a COVID infection. Participants will also need to experience orthostatic intolerance, which is the feeling of dizziness or faintness when standing for a prolonged period. Participants must be able to transport themselves to York University and undergo testing which will take approximately 90 minutes. This includes the ability to undergo a tilt table test for 5 minutes. Therefore, any musculoskeletal problems which prevent upright posture will be excluded. Participants must be able to communicate in English and have the ability to be contacted by email or phone throughout the 12-week period. Current smokers will be excluded. Participants who regularly consume energy drinks that contain taurine (more than once per week) will be excluded.
Key inclusion criteria (1 listed)
- Participants will have had symptoms of Long COVID post-infection for at least 3 months
Key exclusion criteria (4 listed)
- Inability to undergo tilt table testing for 5 minutes
- Inability to transport selves to York University from their homes
- Inability to speak English, or provide a translator
- Blood clotting disorders
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 |
|---|---|---|
| Taurine supplementationParticipants will self-administer 12-wks taurine supplementation | Dietary supplement | Taurine supplementation |
Primary outcome
Orthostatic responses
Time frame: Baseline and 12-weeks
Measure cardiovascular and cerebrovascular responses to upright tilt using beat to beat blood pressure, ECG, and transcranial Doppler.
Vascular function
Time frame: Baseline and 12-weeks
Flow-mediated dilation and EndoPAT response. These techniques concurrently measure endothelial function using the same protocol.
1 secondary outcome
Heart rate variability
Time frame: Over the course of 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Jun 2026.
- Background: PubMed 8598068Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation. 1996 Mar 1;93(5):1043-65. No abstract available.
- Background: PubMed 20952670Thijssen DH, Black MA, Pyke KE, Padilla J, Atkinson G, Harris RA, Parker B, Widlansky ME, Tschakovsky ME, Green DJ. Assessment of flow-mediated dilation in humans: a methodological and physiological guideline. Am J Physiol Heart Circ Physiol. 2011 Jan;300(1):H2-12. doi: 10.1152/ajpheart.00471.2010. Epub 2010 Oct 15.
- Background: PubMed 11788217Corretti MC, Anderson TJ, Benjamin EJ, Celermajer D, Charbonneau F, Creager MA, Deanfield J, Drexler H, Gerhard-Herman M, Herrington D, Vallance P, Vita J, Vogel R; International Brachial Artery Reactivity Task Force. Guidelines for the ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery: a report of the International Brachial Artery Reactivity Task Force. J Am Coll Cardiol. 2002 Jan 16;39(2):257-65. doi: 10.1016/s0735-1097(01)01746-6.
- Background: PubMed 2345839Wittes J, Brittain E. The role of internal pilot studies in increasing the efficiency of clinical trials. Stat Med. 1990 Jan-Feb;9(1-2):65-71; discussion 71-2. doi: 10.1002/sim.4780090113.
- Background: PubMed 26781281Sun Q, Wang B, Li Y, Sun F, Li P, Xia W, Zhou X, Li Q, Wang X, Chen J, Zeng X, Zhao Z, He H, Liu D, Zhu Z. Taurine Supplementation Lowers Blood Pressure and Improves Vascular Function in Prehypertension: Randomized, Double-Blind, Placebo-Controlled Study. Hypertension. 2016 Mar;67(3):541-9. doi: 10.1161/HYPERTENSIONAHA.115.06624. Epub 2016 Jan 18.
- Background: PubMed 38837993Khoramjoo M, Wang K, Srinivasan K, Gheblawi M, Mandal R, Rousseau S, Wishart D, Prasad V, Richer L, Cheung AM, Oudit GY. Plasma taurine level is linked to symptom burden and clinical outcomes in post-COVID condition. PLoS One. 2024 Jun 5;19(6):e0304522. doi: 10.1371/journal.pone.0304522. eCollection 2024.
- Background: PubMed 35248780Oikonomou E, Souvaliotis N, Lampsas S, Siasos G, Poulakou G, Theofilis P, Papaioannou TG, Haidich AB, Tsaousi G, Ntousopoulos V, Sakka V, Charalambous G, Rapti V, Raftopoulou S, Syrigos K, Tsioufis C, Tousoulis D, Vavuranakis M. Endothelial dysfunction in acute and long standing COVID-19: A prospective cohort study. Vascul Pharmacol. 2022 Jun;144:106975. doi: 10.1016/j.vph.2022.106975. Epub 2022 Mar 3.
- Background: PubMed 33306450Ratchford SM, Stickford JL, Province VM, Stute N, Augenreich MA, Koontz LK, Bobo LK, Stickford ASL. Vascular alterations among young adults with SARS-CoV-2. Am J Physiol Heart Circ Physiol. 2021 Jan 1;320(1):H404-H410. doi: 10.1152/ajpheart.00897.2020. Epub 2020 Dec 11.
- Background: PubMed 32325026Varga Z, Flammer AJ, Steiger P, Haberecker M, Andermatt R, Zinkernagel AS, Mehra MR, Schuepbach RA, Ruschitzka F, Moch H. Endothelial cell infection and endotheliitis in COVID-19. Lancet. 2020 May 2;395(10234):1417-1418. doi: 10.1016/S0140-6736(20)30937-5. Epub 2020 Apr 21. No abstract available.
- Background: PubMed 32142651Hoffmann M, Kleine-Weber H, Schroeder S, Kruger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Muller MA, Drosten C, Pohlmann S. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 2020 Apr 16;181(2):271-280.e8. doi: 10.1016/j.cell.2020.02.052. Epub 2020 Mar 5.
- Background: PubMed 35934007Ballering AV, van Zon SKR, Olde Hartman TC, Rosmalen JGM; Lifelines Corona Research Initiative. Persistence of somatic symptoms after COVID-19 in the Netherlands: an observational cohort study. Lancet. 2022 Aug 6;400(10350):452-461. doi: 10.1016/S0140-6736(22)01214-4.
- Individual participant dataSharing planned: No. It is against REB protocol to provide individual data, particularly in small sample size studies.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Long COVID Syndrome, run by York University at 1 site in Canada.
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 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: looking for participants now, as of the sponsor's last update on 5 Jun 2026. 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 Canada. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Heather Edgell, PhD (14167362100 ext. 22927, edgell@yorku.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Orthostatic responses (time frame: Baseline and 12-weeks). The study lists 2 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 NCT07312409, which also lists 11 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 5 Jun 2026.