Serum FSTL1 Levels in Women With Fibromyalgia: A Case-Control Study (FMS-FSTL1)

November 4, 2026 updated by: Zeynep Karakuzu Güngör, Kanuni Sultan Suleyman Training and Research Hospital

Evaluation of the Relationship Between Serum Follistatin-Like Protein 1 (FSTL1) Levels and Clinical and Functional Parameters in Fibromyalgia Syndrome

This observational, cross-sectional case-control study aims to evaluate serum Follistatin-Like Protein 1 (FSTL1) levels in women with fibromyalgia syndrome (FMS) and healthy controls. A total of 60 women aged 18-50 years will be included, comprising 30 patients with FMS and 30 healthy controls.

Serum FSTL1 levels will be compared between the groups. Associations between FSTL1 levels and pain sensitivity, handgrip strength, fatigue, pain severity, and functional status will also be investigated.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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.

Detailed Description

This single-center, observational, cross-sectional case-control study will investigate serum Follistatin-Like Protein 1 (FSTL1) levels and their associations with clinical and functional parameters in women with fibromyalgia syndrome (FMS).

The study will include 60 women aged 18-50 years: 30 patients diagnosed with FMS according to the 2016 ACR criteria and 30 healthy controls.

Serum FSTL1 levels will be measured and compared between groups. Clinical assessments will include pressure pain thresholds, handgrip strength, fatigue severity, pain intensity, and functional status.

The relationships between serum FSTL1 levels and clinical parameters will be analyzed. All assessments will be performed during a single study visit, without any therapeutic intervention.

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 (Estimated)

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.
60

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

18 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of 60 women aged 18-50 years, including 30 patients diagnosed with fibromyalgia syndrome according to the 2016 ACR criteria and 30 healthy controls without fibromyalgia or chronic widespread pain. Participants will be recruited from Kanuni Sultan Suleyman Training and Research Hospital and healthy volunteers from the hospital staff and community.

Description

Inclusion Criteria:Women aged 18-50 years.

Patients diagnosed with fibromyalgia syndrome according to the 2016 ACR criteria.

Healthy controls without fibromyalgia or chronic widespread pain.

Ability to complete clinical and functional assessments.

Provision of written informed consent.

Exclusion Criteria:

Hematological, endocrine, inflammatory rheumatic, autoimmune, renal, cardiovascular, gastrointestinal, or respiratory diseases.

Active infection, history of malignancy, or vitamin D deficiency.

Surgery or major trauma within the previous year.

Pharmacological or non-pharmacological treatment for fibromyalgia within the previous 3 months.

Current smoking.

Pregnancy or breastfeeding.

Neurological or musculoskeletal conditions affecting handgrip strength or pressure pain threshold measurements.

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

  • Observational Models: CASE_CONTROL
  • Time Perspectives: PROSPECTIVE

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.
Fibromyalgia Group

Thirty women aged 18-50 years diagnosed with fibromyalgia syndrome according to the 2016 ACR criteria. Serum FSTL1 levels and clinical and functional parameters will be evaluated.

Kopyala
Healthy Control Group

Thirty healthy women aged 18-50 years without fibromyalgia syndrome or chronic widespread pain. Serum FSTL1 levels and clinical and functional parameters will be evaluated.

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
Serum Follistatin-Like Protein 1 (FSTL1) Levels
Time Frame: Baseline (single study visit)

Serum FSTL1 concentrations will be measured using ELISA and compared between women with fibromyalgia and healthy controls.
Baseline (single study visit)

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
Pressure Pain Threshold (PPT)
Time Frame: Baseline (single study visit)

Pressure pain thresholds will be measured using an algometer at the bilateral upper trapezius and tibialis anterior muscles.
Baseline (single study visit)
Handgrip Strength
Time Frame: Baseline (single study visit)

Handgrip strength will be measured bilaterally using a hand dynamometer. Three measurements will be performed for each hand, and strength will be recorded in kilograms (kg).
Baseline (single study visit)
Fatigue Severity Scale (FSS) Score
Time Frame: Baseline (single study visit)

Fatigue severity will be assessed using the Fatigue Severity Scale (FSS). Higher scores indicate greater fatigue severity.
Baseline (single study visit)
Revised Fibromyalgia Impact Questionnaire (FIQR) Score
Time Frame: Baseline (single study visit)

The impact of fibromyalgia on symptoms and daily functioning will be assessed using the Revised Fibromyalgia Impact Questionnaire (FIQR). Total scores range from 0 to 100, with higher scores indicating greater disease impact.
Baseline (single study visit)
Pain Intensity Score
Time Frame: Baseline (single study visit)

Pain intensity will be assessed using a standardized 0-10 pain rating scale, with higher scores indicating greater pain intensity.
Baseline (single study visit)

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.
Kanuni Sultan Suleyman Training and Research Hospital

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 (Estimated)

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.
November 15, 2026

Primary Completion (Estimated)

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.
January 30, 2027

Study Completion (Estimated)

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.
February 15, 2027

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).
November 4, 2026

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.
November 4, 2026

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.
November 10, 2026

Study Record Updates

Last Update Posted (Actual)

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.
November 10, 2026

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.
November 4, 2026

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.
November 1, 2026

More Information

Terms related to this study

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.
  • FMS-FSTL1-2026-001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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