An observational study in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome, sponsored by University Medical Center Groningen. Recruiting at 1 site in Netherlands. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-21.
Sponsored by University Medical Center Groningen · Observational
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Exercise is an important contributor to general health and is considered a potential remedy for chronic diseases. This is in strong contrast with the observation that in most myalgic encephalomyelitis (ME/CFS) patients exercise aggravates their symptoms. Recently, post-exertional malaise (PEM) is defined as the key symptom of ME/CFS. The etiology and pathophysiological mechanisms underlying ME/CFS are still unknown and objective diagnostic criteria are not available. Various hypotheses are postulated including disorders of several organ systems but the heterogenous presentation of symptoms in patients, and the multisystem deficits complicate reaching an all-encompassing hypothesis. It seems therefore reasonable to focus on the key symptom, i.e., PEM. PEM can be induced by minor cognitive or physical exertion and can be assessed with questionnaires. Acute physical activity triggers complex cardiovascular, metabolic, and molecular responses and for ME/CFS, hence it is important to understand the relation between these acute processes and the prolonged presentation of aggravated symptoms (PEM). We therefore want to measure metabolites, cardiovascular responses, cognitive performance, muscle force and fatigability in 50 patients and 50 controls matched on group level for sex, age, and activity. To follow changes in these parameters we perform time-series analysis, including data obtained before, during and after task performance. Besides understanding these interactions, it is also essential to understand how these acute and prolonged responses affect behaviour and perception.
264 studies on the registry are indexed under Fatigue Syndrome, Chronic; 62 are open to participants now.
This study's planned enrollment of 100 is below the median of 150 across 77 observational studies indexed under Fatigue Syndrome, Chronic.
Browse Fatigue Syndrome, Chronic studies →University Medical Center Groningen is the lead sponsor of 627 studies on the registry; 175 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with diagnosed ME/CFS according to the international consensus criteria or the canadian consensus criteria and 50 controls matched on group level for age, sex, and activity.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Additional inclusion criteria for ME/CFS patients
Exclusion Criteria:
Additional exclusion criteria for control subjects:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
50 patients diagnosed with ME/CFS according to the International Consensus Criteria (ICC) and Canadian Consensus Criteria (CCC) will be included
Other: No intervention is planned
50 sex, age and activity matched controls will be included
Other: No intervention is planned
Investigation of the pathophysiology of PEM in ME/CFS patients and matched controls
Cardiovascular parameters (Heart rate and blood pressure)
Heart rate (bpm) and blood pressure (mmHg) are measured with a continuous non-invasive monitoring system (Finapres Midi). The BP sensor is positioned around the middle finger on the second phalanx of the left hand and subjects must hold their arm at breast level. The recorded values during T1 and T2 will be compared between tasks, as well as between groups and sessions.
Time frame: 2023-2027
Short maximal voluntary contraction
Short isometric maximal voluntary contractions (MVC) of the right index finger abductor (FDI). The maximal index finger abduction force (newton) is measured with a force transducer which is held by the participant. The measurement is repeated 3 times per hand and the highest value is taken. On the second and third repetition, a superimposed twitch stimulation (SIT) will be induced to assess the voluntary activation during maximal contraction.
Time frame: 2023-2027
Submaximal voluntary contractions (20%,40%, 60% of the short MVC)
The participant is asked to produce force at different submaximal force targets (20%, 40%, 60%). The targets are presented on a monitor and subjects get online feedback of the target force and their produced force.
Time frame: 2023-2027
Sustained maximal voluntary contraction of the FDI
The participant performs a maximal contraction for 2 minutes. During the 2 minutes contraction 7 SIT stimulation are given to the subject to assess voluntary muscle activation during a fatiguing task.
Time frame: 2023-2027
Cognitive parameters (stroop task)
This test assesses the ability to inhibit cognitive interference, which occurs when the processing of a stimulus feature affects the simultaneous processing of another attribute of the same stimulus. Participants see a word describing a colour on a screen, the word is written in the same or different colour than the word they will read. They are asked to press a yes or no button to indicate whether the colour of the word and the meaning of the word matches (yes) or not (no). The number of correct answers and the reaction time will be assessed.
Time frame: 2023-2027
BOLD activation
Blood oxygenation level dependent (BOLD): changes both in oxy- and deoxyhemoglobin concentration. Brain activation in different tasks will be compared between groups and sessions.
Time frame: 2023-2027
Arterial Spin Labeling (ASL)
Is a non-invasive fMRI technique that uses arterial water as an endogenous tracer to measure cerebral blood flow. ASL provides reliable absolute quantification of cerebral blood flow with high spatial and temporal resolution. Perfusion data are used to identify patients suffering from impaired autoregulation of cerebral blood flow and to obtain associations with cardiovascular responses and muscle fatigue.
Time frame: 2023-2027
Cerebral oxygenation (near infrared spectroscopy)
Oxy- and deoxyhemoglobine concentrations are measured at the prefrontal cortex and leg muscle with a non-invasive near infrared spectroscopy device (NIRS), where small sensors are positioned on the forehead and the quadriceps muscle. For this measurement a standardized vascular occlusion test will be performed on the quadriceps muscle to assess the local tissue oxygen consumption and the microvascular reperfusion and reactivity. This measurement will be used as calibration to normalize per subject the oxy- and deoxyhemoglobin concentrations allowing for comparisons between subjects. The oxygenated and deoxygenated values for the prefrontal cortex and leg muscle will be compared across tasks, groups and sessions.
Time frame: 2023-2027
30 Chair to stand test
This test assesses functional lower extremity strength. Subjects sit on a chair and stand up repeatedly for 30 s. Arms of the subject are crossed and held against the chest. The number of cycles of standing up from sitting are counted.
Time frame: 2023-2027
Handgrip force (kg)
MVC of the handgrip is measured with a hydraulic hand dynamometer (JAMAR Hand Dynamometer). The measurement is repeated 3 times.
Time frame: 2023-2027
Activity monitor
To measure routine activities in daily life, participants will be asked to wear an activity device (Actigraph) on their dominant hip as well as a heart rate device (polar H10) around their chest. During the 7 days of wearing the devices participant will be asked to fill out an activity diary. The difference in activity level and heart rate variables will be compared across the groups.
Time frame: 2023-2027
Blood samples
The blood samples are used to analyse the short-lasting changes in metabolites before and after the performance of physical and cognitive tasks and long-lasting changes on the next day
Time frame: 2023-2027
Knee extension force
Maximal voluntary force (MVC) of the knee extensors is measured with a custom-built dynamometer. Subjects are seated in a chair with the knee and hip in 90° of flexion with their non-dominant lower leg strapped to the chair's lever arm (\~ 10 cm up to lateral malleolus). Subjects are instructed to contract their knee extensors as rapidly and forcefully as possible and to maintain force generation for 5 s. MVC is determined as the peak force.
Time frame: 2023-2027
Chalder fatigue scale
Is a questionnaire used to measure the severity of tiredness in fatiguing illnesses. Scores per question range from 0 to 3. The higher the score the more fatigue experienced.
Time frame: 2023-2027
SF-36
It is a multipurpose, short-form health survey with 36 questions. It yields an eight-scale profile of scores as well as physical and mental health summary measures. It is useful in comparing general and specific populations and comparing the relative burden of diseases. Higher scores indicate a better health status.
Time frame: 2023-2027
DePaul Symptoms Questionnaire 2 (DSQ-2)
DSQ-2 is a questionnaire that assesses the key symptoms of ME/CFS. At each item, participants have to rate the frequency and severity of the symptom on a scale from 0 to 4. The higher the scores the worse the symptoms.
Time frame: 2023-2027
Bell disability scale
Bell scale is a scale that describes the levels of physical and mental activity health. The scores range from 0 to 100, the higher the score the better the health.
Time frame: 2023-2027
Pittsburgh sleep quality index
Is a questionnaire assessing sleep quality and disturbances. The higher the score the worse the sleep quality.
Time frame: 2023-2027
Hospital Anxiety and Depression Scale
Is a questionnaire to determine levels of anxiety and depression that a person is experiencing. Higher scores reflect a stronger impact.
Time frame: 2023-2027
Composite Autonomic Symptom Score 31
Is a questionnaire of 31 questions that assesses the autonomic nervous system symptoms. Higher score indicates greater autonomic symptom severity.
Time frame: 2023-2027
Modified Fatigue Impact Scale (MFIS)
Is a questionnaire related to sense of fatigue. The questionnaire consists of 21 questions providing assessment of the effect of fatigue in terms of physical, cognitive, and psychosocial function. Higher scores reflect a higher impact of fatigue.
Time frame: 2023-2027
DePaul Post-Exertional Malaise Questionnaire (DPEMQ)
Is a questionnaire that assesses the onset, triggers and recovery of PEM.
Time frame: 2023-2027
EQ-5D
Is a questionnaire that measures an individual's health status. It has five dimensions on mobility, usual activities, self-care, pain and discomfort and anxiety and depression. The higher the score the higher the impact on the quality of life.
Time frame: 2023-2027
Symptom severity score (SSS-12)
Is a questionnaire that assesses the severity of 12 main symptoms from o to 10, with 10 being the most severe.
Time frame: 2023-2027
Plan to share: No
No publications or documents are linked to this record.
Started May 2024 (actual). Primary completion is estimated for Oct 2026, 29 months after the start.
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