Post-COVID-19NCT04961255
Effects of Post-COVID-19 on Quadriceps Femoral Muscle-tendon Unit
An observational study of Post-COVID-19 and Healthy Participants, run by University of Brasilia at 1 site in Brazil.
Trial summary
The physiological/biomechanical characteristics related to muscle and tendon architecture and their possible relationship with the loss of muscle strength and fatigue in patients who were infected with COVID-19 are totally unknown. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Post-COVID-19, Healthy Participants
- How many people
- 90 participants
- Where
- 1 siteBrazil
- Study dates
- 24 Aug 2021to 30 Dec 2024
- 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 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Female and male participants aged between 18 and 80 years who had tested positive for COVID-19 will be included in this study. In addition, the control group will include healthy participants who had not tested positive for COVID-19.
Who may be able to join
- Control group:
- The control group will include healthy participants, aged 18 and 80 years, who had not tested positive for COVID-19.
- COVID-19 positive participants who had moderate symptoms group:
- Female and male participants, aged between 18 and 80 years, who had Molecular test (RT-PCR) or serological test, which assesses whether the samples are reactive to immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies, positive for COVID-19;
- Presence of some of the following symptoms, without the need for hospitalization: dry cough, runny nose, sore throat, diffuse body pain, persistent hyperthermia, no hypoxemia.
- COVID-19 positive participants who had severe symptoms group:
- Female and male participants, aged between 18 and 80 years, who had Molecular test (RT-PCR) or serological test (which assesses whether the samples are reactive to IgM and IgG antibodies) positive for COVID-19;
- Presence of hypoxemia (peripheral oxygen saturation - SPO2 ≤ 93%) requiring hospitalization with or without intubation, in addition to the symptoms described for the COVID-19 positive participants who had moderate symptoms group.
Who cannot join
- Body Mass Index (BMI) ≥ 35 kg/m2;
- Pregnancy;
- Pain, swelling, dermal damage, deformity, or amputation in the regions to be examined;
- Diagnosis of ankylosing spondylitis, rheumatoid arthritis, severe heart disease, advanced chronic obstructive pulmonary disease, cognitive impairment, chemical dependency, psychiatric illness, or behavioral that makes it difficult to cooperate with the procedures.
Trial locations and contacts
1 site in 1 country.
Brazil1 site, 1 recruiting
- Recruiting
University of Brasilia
Brasília, Federal District, 72220-900
isabella S Almeida, +55 613356-9148, isabellafisioucb@gmail.com
João LQ Durigan, PhD, +55 61 3107-8450, joaodurigan@gmail.com
About this study
Official title: Effects of Post-COVID-19 on Neural Activation and Architecture of the Quadriceps Femoral Muscle-tendon Unit and Its Correlation With Inflammatory Markers
The physiological/biomechanical characteristics related to muscle and tendon architecture and their possible relationship with the loss of muscle strength and fatigue in patients who were infected with COVID-19 are totally unknown. The aim of this study is to evaluate inflammatory markers, the isometric maximum voluntary force of the knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, tendinous properties of quadriceps components, oxygen extraction, and body composition in participants after diagnosis with Covid-19 who had moderate and severe levels of involvement compared to a healthy control group.
Read the detailed description
The groups will be composed of participants who had COVID-19, except for the control group, which will be composed of healthy participants who did not have COVID-19. Participants will be divided into: (1) control group, (2) COVID-19 positive participants who had moderate symptoms, (3) COVID-19 positive participants who had severe symptoms. Participants will be recruited from 21 days after the onset of symptoms, the period recommended by the scientific community that the patient no longer transmits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After recruitment, 4 evaluations will be carried out over 1 year.
- Conditions
- Post-COVID-19, Healthy Participants
- Keywords
- COVID-19, muscle, tendon, cytokines, electrodiagnosis, fatigue, strength, peripheral oxygen extraction
- Medical subject headings
- COVID-19, Fatigue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Control group | Healthy individuals will be evaluated only once throughout the study. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated. | |
| COVID-19 positive participants who had moderate symptoms group | These participants will be evaluated 4 times throughout the study. Baseline 1: This will be performed between 21 to 30 days after the onset of symptoms of COVID-19 infection. Assessment 2: This will be performed between 31 to 90 days after the onset of symptoms of COVID-19 infection. Assessment 3: This will be carried out between 91 and 180 days after the onset of symptoms of COVID-19 infection. Assessment 4: This will be performed between 181 to 360 days after the onset of symptoms of COVID-19 infection. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated in each assessment. | |
| COVID-19 positive participants who had severe symptoms group | These participants will be evaluated 4 times throughout the study. Baseline 1: This will be performed between 21 to 30 days after the onset of symptoms of COVID-19 infection. Assessment 2: This will be performed between 31 to 90 days after the onset of symptoms of COVID-19 infection. Assessment 3: This will be carried out between 91 and 180 days after the onset of symptoms of COVID-19 infection. Assessment 4: This will be performed between 181 to 360 days after the onset of symptoms of COVID-19 infection. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated in each assessment. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Blood biomarkers
Blood biomarkers including metalloproteinase 9, interleukin-6, interleukin-8 and interleukin-10, interleukin 1 beta, tumor necrosis factor alpha type, nitric oxide, as well as creatine kinase will be collected in blood samples by venipuncture in the vein brachial, in heparinized tubes with separating gel using the vacutainer system with ethylenediaminetetraacetic acid (EDTA). The samples will be stored and later analyzed using appropriate techniques.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Sit to stand test
To carry out the test will be used a stopwatch and a chair with the back against a wall, seat height 43 cm from the floor and without armrest. The test consists of measuring how many times the participant can get up and sit down from a chair (counting as a movement) in a period of 30 seconds.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Electrodiagnostic stimulus test
The quadriceps femoris, gastrocnemius, soleus and tibialis anterior muscles will be evaluated. At the muscle motor point, the values of rheobase, chronaxia and accommodation will be investigated.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Body composition
Body composition will be estimated using dual x-ray absorptiometry. Fat mass and fat-free mass will be expressed in absolute values.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Muscle force
Muscle force will be assessed by muscle force changes, based on the torque generated during maximum voluntary contraction.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Peripheral oxygen extraction
The assessment of peripheral oxygen extraction will be performed both in rest and during voluntary contraction. The evaluation will be carried out by means of near-infrared spectroscopy (NIRS or near infrared spectroscopy).
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Surface electromyographic activity
Electromyographic activity of each superficial component of the quadriceps muscle both in rest and during voluntary contraction.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Muscle architecture
Muscle architecture analyzes will be performed using ultrasound at rest and during voluntary contraction. The muscle volume of the knee extensors, muscle thickness, pennation angle, fascicle length and muscle echogenicity will be evaluated.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Properties of the patellar tendon
The morphological, material and mechanical properties will be evaluated based from the elongation of the patellar tendon during maximum voluntary contraction.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Muscle fatigue
Quadriceps muscle fatigue will be assessed in each leg after consecutive maximal isometric voluntary contractions of the quadriceps muscle.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Assessment of perceived exertion during the fatigue protocol
Assessment of perceived exertion will be analyzed before, during, and after the performance of maximum voluntary isometric contractions performed to analyze muscle fatigue using the BORG scale of perceived exertion.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Fatigue severity analysis
Fatigue severity analysis will be assessed using the fatigue severity scale.
Measured: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jul 2021
- Study start24 Aug 2021
- Primary completion30 Aug 2024 (estimated)
- Study completion30 Dec 2024 (estimated)
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 Post-COVID-19Studies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Brasilia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, João Luiz Q. Durigan, University of Brasilia
- Investigators
- João LQ Durigan, PhD, Principal investigator, University of Brasilia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04961255
- Sponsor's protocol ID
- CAAE: 45043821.0.0000.8093
- Status last verified
- Dec 2023
- First submitted
- 6 Jul 2021
- Last updated
- 5 Dec 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Salomao R, Pasquarelli-do-Nascimento G, Ananias M, Assis V, Ferreira LGJ, da Silva Almeida I, Silva L, Tostes K, Sorroche BP, Arantes LMRB, Magalhaes KG, Garcia LT, Rocha Costa R, Quagliotti Durigan JL, Marqueti RC. Longitudinal trajectories of hematological indices and serum metalloproteinases-2 and 9 over 1 year after moderate and severe COVID-19. Front Med (Lausanne). 2026 Jun 12;13:1824883. doi: 10.3389/fmed.2026.1824883. eCollection 2026.
PubMed 42369154da Silva Almeida I, de Jesus Ferreira LG, Vaz MA, Costa RR, Babault N, de Cassia Marqueti R, Durigan JLQ. Muscle fatigue in patients with severe long COVID: A 2-year follow-up study. PM R. 2026 Jun 16. doi: 10.1002/pmrj.70165. Online ahead of print.
PubMed 42300213Almeida IDS, Ferreira LGJ, Vaz MA, Cipriano Junior G, de Resende MA, Vieira DCL, Costa RR, Babault N, Marqueti RC, Durigan JLQ. Fatigue and neuromuscular function in long COVID: A one-year follow-up study. PLoS One. 2025 Sep 24;20(9):e0332242. doi: 10.1371/journal.pone.0332242. eCollection 2025.
PubMed 40991619
Study at a glance
From the registry record, last updated by the sponsor on 5 Dec 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Post-COVID-19 on Neural Activation and Architecture of the Quadriceps Femoral Muscle-tendon Unit and Its Correlation With Inflammatory Markers
- ClinicalTrials.gov ID
- NCT04961255
- Acronym / sponsor ID
- CAAE: 45043821.0.0000.8093
- Conditions
- Post-COVID-19, Healthy Participants
- Keywords
- COVID-19, muscle, tendon, cytokines, electrodiagnosis, fatigue, strength, peripheral oxygen extraction
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- University of BrasiliaUniversity, hospital or other
- Study start
- 24 Aug 2021 (actual)
- Primary completion
- 30 Aug 2024 (estimated)
- Study completion
- 30 Dec 2024 (estimated)
- First posted
- 14 Jul 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.
The physiological/biomechanical characteristics related to muscle and tendon architecture and their possible relationship with the loss of muscle strength and fatigue in patients who were infected with COVID-19 are totally unknown. The aim of this study is to evaluate inflammatory markers, the isometric maximum voluntary force of the knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, tendinous properties of quadriceps components, oxygen extraction, and body composition in participants after diagnosis with Covid-19 who had moderate and severe levels of involvement compared to a healthy control group.
Detailed description
The groups will be composed of participants who had COVID-19, except for the control group, which will be composed of healthy participants who did not have COVID-19. Participants will be divided into: (1) control group, (2) COVID-19 positive participants who had moderate symptoms, (3) COVID-19 positive participants who had severe symptoms. Participants will be recruited from 21 days after the onset of symptoms, the period recommended by the scientific community that the patient no longer transmits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After recruitment, 4 evaluations will be carried out over 1 year.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Control group | – | –Healthy individuals will be evaluated only once throughout the study. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated. |
| COVID-19 positive participants who had moderate symptoms group | – | –These participants will be evaluated 4 times throughout the study. Baseline 1: This will be performed between 21 to 30 days after the onset of symptoms of COVID-19 infection. Assessment 2: This will be performed between 31 to 90 days after the onset of symptoms of COVID-19 infection. Assessment 3: This will be carried out between 91 and 180 days after the onset of symptoms of COVID-19 infection. Assessment 4: This will be performed between 181 to 360 days after the onset of symptoms of COVID-19 infection. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated in each assessment. |
| COVID-19 positive participants who had severe symptoms group | – | –These participants will be evaluated 4 times throughout the study. Baseline 1: This will be performed between 21 to 30 days after the onset of symptoms of COVID-19 infection. Assessment 2: This will be performed between 31 to 90 days after the onset of symptoms of COVID-19 infection. Assessment 3: This will be carried out between 91 and 180 days after the onset of symptoms of COVID-19 infection. Assessment 4: This will be performed between 181 to 360 days after the onset of symptoms of COVID-19 infection. Inflammatory markers, the isometric maximum voluntary force of knee extensor torque, muscle fatigue, neuromuscular adaptations, muscle architecture, quadriceps tendon properties, peripheral oxygen extraction, and body composition will be evaluated in each assessment. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Female and male participants aged between 18 and 80 years who had tested positive for COVID-19 will be included in this study. In addition, the control group will include healthy participants who had not tested positive for COVID-19.
Key inclusion criteria (8 listed)
- Control group:
- COVID-19 positive participants who had moderate symptoms group:
- COVID-19 positive participants who had severe symptoms group:
Key exclusion criteria (4 listed)
- Body Mass Index (BMI) ≥ 35 kg/m2;
- Pregnancy;
- Pain, swelling, dermal damage, deformity, or amputation in the regions to be examined;
- Diagnosis of ankylosing spondylitis, rheumatoid arthritis, severe heart disease, advanced chronic obstructive pulmonary disease, cognitive impairment, chemical dependency, psychiatric illness, or behavioral that makes it difficult to cooperate with the procedures.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Blood biomarkers
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Blood biomarkers including metalloproteinase 9, interleukin-6, interleukin-8 and interleukin-10, interleukin 1 beta, tumor necrosis factor alpha type, nitric oxide, as well as creatine kinase will be collected in blood samples by venipuncture in the vein brachial, in heparinized tubes with separating gel using the vacutainer system with ethylenediaminetetraacetic acid (EDTA). The samples will be stored and later analyzed using appropriate techniques.
Sit to stand test
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
To carry out the test will be used a stopwatch and a chair with the back against a wall, seat height 43 cm from the floor and without armrest. The test consists of measuring how many times the participant can get up and sit down from a chair (counting as a movement) in a period of 30 seconds.
Electrodiagnostic stimulus test
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
The quadriceps femoris, gastrocnemius, soleus and tibialis anterior muscles will be evaluated. At the muscle motor point, the values of rheobase, chronaxia and accommodation will be investigated.
Body composition
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Body composition will be estimated using dual x-ray absorptiometry. Fat mass and fat-free mass will be expressed in absolute values.
Muscle force
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Muscle force will be assessed by muscle force changes, based on the torque generated during maximum voluntary contraction.
Peripheral oxygen extraction
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
The assessment of peripheral oxygen extraction will be performed both in rest and during voluntary contraction. The evaluation will be carried out by means of near-infrared spectroscopy (NIRS or near infrared spectroscopy).
Surface electromyographic activity
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Electromyographic activity of each superficial component of the quadriceps muscle both in rest and during voluntary contraction.
Muscle architecture
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Muscle architecture analyzes will be performed using ultrasound at rest and during voluntary contraction. The muscle volume of the knee extensors, muscle thickness, pennation angle, fascicle length and muscle echogenicity will be evaluated.
Properties of the patellar tendon
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
The morphological, material and mechanical properties will be evaluated based from the elongation of the patellar tendon during maximum voluntary contraction.
Muscle fatigue
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Quadriceps muscle fatigue will be assessed in each leg after consecutive maximal isometric voluntary contractions of the quadriceps muscle.
Assessment of perceived exertion during the fatigue protocol
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Assessment of perceived exertion will be analyzed before, during, and after the performance of maximum voluntary isometric contractions performed to analyze muscle fatigue using the BORG scale of perceived exertion.
Fatigue severity analysis
Time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.
Fatigue severity analysis will be assessed using the fatigue severity scale.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Dec 2023.
- Derived from this study: PubMed 42369154Salomao R, Pasquarelli-do-Nascimento G, Ananias M, Assis V, Ferreira LGJ, da Silva Almeida I, Silva L, Tostes K, Sorroche BP, Arantes LMRB, Magalhaes KG, Garcia LT, Rocha Costa R, Quagliotti Durigan JL, Marqueti RC. Longitudinal trajectories of hematological indices and serum metalloproteinases-2 and 9 over 1 year after moderate and severe COVID-19. Front Med (Lausanne). 2026 Jun 12;13:1824883. doi: 10.3389/fmed.2026.1824883. eCollection 2026.
- Derived from this study: PubMed 42300213da Silva Almeida I, de Jesus Ferreira LG, Vaz MA, Costa RR, Babault N, de Cassia Marqueti R, Durigan JLQ. Muscle fatigue in patients with severe long COVID: A 2-year follow-up study. PM R. 2026 Jun 16. doi: 10.1002/pmrj.70165. Online ahead of print.
- Derived from this study: PubMed 40991619Almeida IDS, Ferreira LGJ, Vaz MA, Cipriano Junior G, de Resende MA, Vieira DCL, Costa RR, Babault N, Marqueti RC, Durigan JLQ. Fatigue and neuromuscular function in long COVID: A one-year follow-up study. PLoS One. 2025 Sep 24;20(9):e0332242. doi: 10.1371/journal.pone.0332242. eCollection 2025.
- Individual participant dataSharing planned: No
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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.
João LQ Durigan, PhD principal investigator
University of Brasilia
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 Post-COVID-19 and Healthy Participants, run by University of Brasilia at 1 site in Brazil.
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 8 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: status not confirmed, as of the sponsor's last update on 5 Dec 2023. 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 Brazil. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Rita CM Durigan, PhD (+55 61 3107-8450, marqueti@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Blood biomarkers (time frame: Change from baseline 1 (days 21-30) to assessments 2 (days 31-90), 3 (days 91-180), and 4 (days 181 to 360) for groups composed of COVID-19 positive participants. The Control group will be assessed only at baseline.). The study lists 12 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 NCT04961255, 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 5 Dec 2023.