The Role of Epigenetic Mechanisms in Stress Intolerance in Patients With Chronic Widespread Pain (EPISIP)

September 15, 2025 updated by: Jo Nijs, Vrije Universiteit Brussel
Patients with chronic widespread pain (CWP) frequently experience stress intolerance - an exacerbation of symptoms in response to stress. Although it severely affects their quality of life, stress intolerance remains a mystery. Hence, unravelling the mechanisms underlying stress intolerance is crucial to understand CWP pathophysiology and to develop novel treatments. Epigenetic mechanisms hold the potential to provide an answer as they have been found to be altered in patients with CWP at baseline, and in response to stress. However, research on epigenetic mechanisms in CWP is very scarce. Hence, this study aims to address this knowledge gap by assessing stress-induced epigenetic changes in patients with CWP and healthy controls aiming to unravel whether epigenetic mechanisms can help explain stress intolerance. The regulatory role of epigenetic mechanisms will be researched in relation to the activity of enzymes affected by the epigenetic mechanisms, neurophysiological measures, and stress-induced symptom changes in patients with CWP.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The objectives of this project will be tackled by a randomized cross-over study including 44 patients with CWP and 44 healthy controls. Participants are expected to come to the hospital twice and fill in questionnaires at several defined timepoints. Two days before their first visit, participants will complete baseline questionnaires at home via REDCap, which will take approximately one hour. Next, participants will be randomised into Group 1 (undergoing the mental stress test at their first visit and then relaxation breathing) or Group 2 (undergoing relaxation breathing at their first visit and then the mental stress test). During each hospital visit, the participants will be assessed before, during and after the intervention. The Pre-test assessment consists of a blood withdrawal, five short questionnaires, examination of pain thresholds, and neurophysiological measurements. The latter will continue during the intervention, which consists of a mental stress test or relaxation breathing. The Post-test assessment consists of a blood withdrawal, one short questionnaire, examination of pain thresholds, and neurophysiological measurements. Then there are again 2 home-based assessments via REDCap 24h and 7 days after the intervention during which the participants will in 1 or 5 short questionnaires, respectively.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
84

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Belgium
    • Brussels Capital
      • Brussels, Brussels Capital, Belgium, 1050
        • Vrije Universiteit Brussel - UZ Brussel

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Potential study participants will be recruited mainly through online advertisements, but also in hospitals.

Description

Inclusion Criteria:

  • female
  • age between 18 and 70 years old
  • body mass index (BMI) below 30
  • inactive lifestyle
  • for patients only: received the diagnosis of fibromyalgia

Exclusion Criteria:

  • other neurological, endocrine, cardiac, or systemic syndromes
  • history of cancer or heart failure
  • women that are pregnant or within one year after pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Women with chronic widespread pain
Women who received the diagnosis of fibromyalgia from a doctor.
Other: Montreal Imaging Stress Test
A mental stress test that induces stress via a series of arithmetic tasks participants need to solve in a few seconds.
Other: Relaxation breathing
3 short sessions (4 minutes) of relaxation breathing
Healthy women
Healthy women without any chronic diseases or pain in daily life.
Other: Montreal Imaging Stress Test
A mental stress test that induces stress via a series of arithmetic tasks participants need to solve in a few seconds.
Other: Relaxation breathing
3 short sessions (4 minutes) of relaxation breathing

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
DNA methylation of catecholamine-degrading enzymes
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
DNA methylation status of catechol-O-methyltransferase (COMT), monoamine oxidase (MAO)-A and MAO-B
At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Genetic variations in catecholamine-degrading enzymes
Time Frame: At baseline
COMT: rs4818; rs4680 MAO-A: rs6323; MAOA-uVNTR MAO-B: rs1799836 COMT: rs4818; rs4680 MAO-A: rs6323; MAOA-uVNTR MAO-B: rs1799836 COMT: rs4818; rs4680 MAO-A: rs6323; MAOA-uVNTR MAO-B: rs1799836 COMT: rs4818; rs4680; MAO-A: rs6323; MAOA-uVNTR; MAO-B: rs1799836
At baseline
Catecholamine levels
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Levels of adrenaline, noradrenaline and dopamine in plasma
At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Heart rate variability
Time Frame: Continuously starting 10 minutes before until 10 minutes after the mental stress test and relaxation breathing
Heart rate variability measured continuously using the Polar H10
Continuously starting 10 minutes before until 10 minutes after the mental stress test and relaxation breathing
Blood pressure
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), during (3 times with 4 minutes in between) and 10 minutes after the mental stress test and relaxation breathing
Blood pressure, both systolic and diastolic, measured at specified moments using a digital device
At baseline (i.e. before the mental stress test or relaxation breathing), during (3 times with 4 minutes in between) and 10 minutes after the mental stress test and relaxation breathing
Activity of catecholamine-degrading enzymes
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Activity of the enzymes will be defined in plasma or PBMCs
At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Symptom severity
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), and 10 minutes, 24 hours and 7 days after the mental stress test and relaxation breathing
Symptom severity which is assessed through the Chronic Fatigue Syndrome Symptom List
At baseline (i.e. before the mental stress test or relaxation breathing), and 10 minutes, 24 hours and 7 days after the mental stress test and relaxation breathing

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Temperature and pressure pain thresholds
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Pain thresholds for warmth and cold measured with the TSA-II, and pressure measured with a digital algometer on the hand and leg. Pain intensity is reported through a numeric rating scale ranging from 0 (no pain) to 10 (worst pain).
At baseline (i.e. before the mental stress test or relaxation breathing), and 20 minutes after the mental stress test and relaxation breathing
Level of stress
Time Frame: At baseline (i.e. before the mental stress test or relaxation breathing), during (3 times with 4 minutes in between) and 10 minutes, 24 hours and 7 days after the mental stress test and relaxation breathing
Numeric rating scale ranging from 0 (no stress) to 10 (worst stress) indicating the level of stress
At baseline (i.e. before the mental stress test or relaxation breathing), during (3 times with 4 minutes in between) and 10 minutes, 24 hours and 7 days after the mental stress test and relaxation breathing

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Vrije Universiteit Brussel

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
KU Leuven
Research Foundation Flanders

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jo Nijs, PhD, Vrije Universiteit Brussel

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 19, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 18, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 18, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 16, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 26, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 19, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 15, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • EC-2022-118

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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