Hematological and Metabolic Markers in Carpal Tunnel Syndrome

August 24, 2026 updated by: Nadide Koca, Ankara Training and Research Hospital

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy, but the severity of symptoms experienced by patients does not always correspond to abnormalities detected by nerve conduction studies. This prospective cross-sectional study investigates whether routinely available metabolic, hematological, and inflammatory markers are associated with CTS and with patient-reported symptom and functional burden.

Adults referred for evaluation of suspected CTS were enrolled. Participants with electrodiagnostically confirmed CTS were compared with symptomatic individuals whose nerve conduction studies were normal. Clinical findings, Boston Carpal Tunnel Questionnaire scores, electrophysiological severity, and blood-based metabolic and inflammatory measures were evaluated. The study aims to better understand whether systemic metabolic and inflammatory factors contribute to the clinical expression of CTS beyond the degree of large-fiber nerve conduction abnormality.

Study Overview

Status

Completed

Conditions

Detailed Description

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and results from compression of the median nerve at the wrist. Although local mechanical compression is central to the disorder, the clinical presentation of CTS varies considerably. Patients with similar nerve conduction abnormalities may report very different levels of pain, paresthesia, weakness, and functional limitation. This variability suggests that systemic metabolic and inflammatory factors may contribute to the clinical expression of CTS in addition to the degree of median nerve conduction abnormality.

Several systemic conditions, including obesity, diabetes mellitus, thyroid disease, and inflammatory disorders, are associated with CTS. Obesity and metabolic dysfunction may increase peripheral nerve vulnerability through metabolic, vascular, and inflammatory mechanisms. Low-grade systemic inflammation has also been investigated as a possible contributor to CTS. Routinely available blood measurements may therefore provide additional information about systemic factors accompanying the disorder.

In recent years, several hematological indices derived from routine blood counts have been used as markers of systemic inflammatory activity. These include the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). Metabolic and inflammation-related measures such as triglycerides, the triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDL), the C-reactive protein-to-albumin ratio (CAR), and the C-reactive protein-albumin-lymphocyte (CALLY) index may also reflect different aspects of systemic metabolic and inflammatory burden.

This prospective cross-sectional study includes adults referred for electrodiagnostic evaluation because of symptoms suggestive of CTS. Participants with electrodiagnostically confirmed median neuropathy at the wrist constitute the CTS group, while symptomatic individuals with normal nerve conduction studies serve as the comparison group. This design allows systemic markers associated with confirmed median nerve involvement to be examined against a clinically relevant symptomatic reference group rather than against asymptomatic healthy volunteers.

Clinical examination and nerve conduction studies are performed according to the study protocol. In participants with confirmed CTS, symptom severity and functional status are assessed using the Boston Carpal Tunnel Questionnaire (BCTQ). Routine hematological, biochemical, metabolic, and inflammatory measurements are obtained from fasting blood samples, and derived inflammatory and metabolic indices are calculated from their component variables.

The study evaluates three related but distinct clinical domains: the presence of electrodiagnostically confirmed CTS, patient-reported symptom and functional burden, and electrodiagnostic severity. The main objective is to determine whether routinely available metabolic and inflammatory measures are associated differently with these domains. In particular, the study examines whether systemic metabolic or inflammatory factors may help explain differences in patient-reported burden that are not fully captured by conventional nerve conduction findings.

Study Type

Observational

Enrollment (Actual)

197

Contacts and Locations

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

Study Locations

Turkey (Türkiye)
- Altindag
  - Ankara, Altindag, Turkey (Türkiye), 06230
    - Department of Physical Therapy and Rehabilitation, University of Health Sciences, Ankara Training and Research Hospital

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

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Patients referred to the Electromyography (EMG) laboratory/clinic with suspected Carpal Tunnel Syndrome (CTS) who underwent electrodiagnostic testing

Description

Inclusion Criteria:

Age between 18-65 years
Having undergone Electromyography (EMG) testing for Carpal Tunnel Syndrome (CTS)-like symptoms
Recent complete blood count, C-Reactive Protein (CRP), and albumin available

Exclusion Criteria:

Age below 18 or above 65 years
Pregnancy
History of wrist trauma or surgical operation
Chronic kidney disease
Gout
Rheumatoid arthritis
Connective tissue disease
Thyroid disorders
Acromegaly
Polyneuropathy
Thoracic outlet syndrome
Brachial plexopathy
Cervical disc herniation
Presence of cardiac pacemaker
Steroid use

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

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Electrodiagnostically Confirmed CTS Group Adults with symptoms suggestive of carpal tunnel syndrome and electrodiagnostic evidence of median neuropathy at the wrist. Participants were evaluated for clinical findings, patient-reported symptom and functional burden, electrodiagnostic severity, and fasting metabolic, hematological, and inflammatory measures.
Symptomatic Electrodiagnostically Normal Control Group Adults referred with symptoms suggestive of carpal tunnel syndrome but with normal nerve conduction studies. Participants were evaluated using the same clinical and fasting metabolic, hematological, and inflammatory measures as the CTS group and served as the symptomatic comparison group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of Systemic Inflammation Response Index (SIRI) as an Inflammatory Marker Time Frame: up to 4 weeks	The systemic inflammation response index (SIRI) is calculated as neutrophil count × monocyte count / lymphocyte count. It reflects the combined effect of neutrophil and monocyte-driven innate immunity versus lymphocyte-mediated adaptive immunity. SIRI has been proposed as a robust marker of inflammation in several chronic diseases. In the current study, SIRI was evaluated in individuals with and without Carpal Tunnel Syndrome (CTS) to investigate its potential as an indicator of inflammatory burden.	up to 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of Platelet/Lymphocyte Ratio (PLR) as an Inflammatory Marker Time Frame: up to 4 weeks	Platelet/lymphocyte ratio (PLR) is another hematological marker that reflects systemic inflammation. During inflammatory responses, platelet counts often increase while lymphocyte counts decrease, resulting in an elevated PLR. Platelets play an active role in inflammation by releasing inflammatory mediators and interacting with leukocytes. PLR, calculated from routine blood tests, has been increasingly used in the assessment of inflammatory conditions. In this study, PLR values were compared between patients with Carpal Tunnel Syndrome (CTS) and healthy controls to evaluate its association with inflammation in CTS.	up to 4 weeks
Evaluation of Monocyte/Lymphocyte Ratio (MLR) as an Inflammatory Marker Time Frame: up to 4 weeks	Monocyte/lymphocyte ratio (MLR) is a peripheral blood marker used to assess systemic inflammatory status. Monocytes contribute to chronic inflammation and tissue remodeling, while lymphocytes are typically reduced in inflammatory states. An increased MLR may reflect an enhanced inflammatory response. Like other ratios, MLR can be easily derived from complete blood count parameters. In this study, MLR was analyzed in patients with and without Carpal Tunnel Syndrome (CTS) to explore its relevance as a potential inflammatory biomarker.	up to 4 weeks
Evaluation of Neutrophil/Lymphocyte Ratio (NLR) as an Inflammatory Marker Time Frame: up to 4 weeks	In inflammatory diseases, the immune response often leads to an increase in circulating neutrophils and a decrease in lymphocytes, resulting in an elevated neutrophil/lymphocyte ratio (NLR). This parameter has recently gained attention as a simple, cost-effective, and readily available marker of systemic inflammation. NLR is derived from routine complete blood count tests and reflects the balance between innate (neutrophils) and adaptive (lymphocytes) immune responses. In the present study, NLR was compared between patients with Carpal Tunnel Syndrome (CTS) and healthy controls to investigate its potential role as a marker of inflammation in CTS.	up to 4 weeks
Evaluation of Systemic Immune-inflammation Index (SII) as an Inflammatory Marker Time Frame: up to 4 weeks	The systemic immune-inflammation index (SII) is a composite marker calculated using the formula: platelet count × neutrophil count / lymphocyte count. It simultaneously incorporates three types of immune cells and is considered a more comprehensive indicator of the systemic inflammatory status. Elevated SII levels have been associated with various inflammatory and immune-mediated conditions. In this study, SII values were compared between CTS patients and healthy controls to assess its potential utility in identifying inflammatory activity in CTS.	up to 4 weeks
- Comparison of C-Reactive Protein levels (CRP) and CALLY Time Frame: up to 4 weeks	- Comparison of C-Reactive Protein levels (CRP) levels between case and control groups. CRP is an acute phase protein used as an inflammatory marker. CRP's half-life is approximately 19 hours, making it a responsive marker that can indicate both the onset of inflammation and the response to treatment relatively quickly. CALLY (C-reactive protein-Albumin-Lymphocyte) index is a composite scoring system that integrates CRP, albumin, and lymphocyte count to reflect both inflammatory status and nutritional-immune condition simultaneously.	up to 4 weeks
Comparison of TG/HDL Time Frame: up to 4 weeks	Comparison of TG/HDL between case and control groups	up to 4 weeks
Evaluation of Electrodiagnostic Severity of Carpal Tunnel Syndrome Time Frame: up to 4 weeks	Electromyography (EMG) is part of electrodiagnostic assessment used to evaluate peripheral nerve and muscle function. In this study, carpal tunnel syndrome severity was classified based on nerve conduction study findings as follows: Mild: Median-ulnar sensory distal latency difference >1.0 ms or median-ulnar fourth-digit peak sensory latency difference >0.5 ms. Moderate: Median motor distal latency >4.0 ms. Severe: Markedly reduced or absent median sensory nerve action potential, median motor amplitude <5.0 mV, or median motor distal latency >5.5 ms.	up to 4 weeks

Collaborators and Investigators

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

Sponsor

Ankara Training and Research Hospital

Investigators

Principal Investigator: Nadide Koca, M.D., University of Health Sciences, Ankara Training and Research Hospital, TURKEY

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

April 20, 2025

Primary Completion (Actual)

April 1, 2026

Study Completion (Actual)

June 1, 2026

Study Registration Dates

First Submitted

April 19, 2025

First Submitted That Met QC Criteria

April 29, 2025

First Posted (Actual)

May 1, 2025

Study Record Updates

Last Update Posted (Actual)

August 25, 2026

Last Update Submitted That Met QC Criteria

August 24, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

AnkaraTRH-FTR-NK-04

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

IPD Plan Description

Individual participant data will not be shared due to institutional policies regarding patient privacy and data protection regulations

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Studies a U.S. FDA-regulated device product

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