Serum Neurofilament Light Chain Levels and Neuropathy Severity in Diabetic Polyneuropathy

NCT07480330 | Not Yet Recruiting

• 1 other identifier: DPN-NFL-2026
• Study Type: observational
• Target: 80
• Locations: 0 countries
• Sites: N/A

Brief Summary

Diabetic polyneuropathy (DPN) is one of the most common chronic complications of diabetes mellitus and is characterized by peripheral nerve damage caused by long-term hyperglycemia. Progressive sensory loss and impairment of proprioception may lead to balance disturbances, gait instability, and an increased risk of falls. Neurofilament Light Chain (NfL) has emerged as a potential biomarker of neuroaxonal injury in several neurological disorders. The aim of this observational cross-sectional study is to investigate the relationship between serum Neurofilament Light Chain (NfL) levels and neuropathy severity, balance performance, and fall risk in patients with diabetic polyneuropathy. Neuropathy severity will be evaluated using the Michigan Neuropathy Screening Instrument (MNSI) and electrophysiological findings, while balance performance and fall risk will be assessed using the Berg Balance Scale and the Falls Efficacy Scale-International (FES-I).

Conditions

Diabetic Polyneuropathy

Outcome Measures

Primary Outcomes (3)

• Serum Neurofilament Light Chain Levels

  To evaluate the association between serum Neurofilament Light Chain (NfL) levels and the presence and severity of diabetic polyneuropathy assessed by the Michigan Neuropathy Screening Instrument (MNSI) and electrophysiological findings.

  At baseline

• Balance Performance

  To evaluate the relationship between serum Neurofilament Light Chain (NfL) levels and balance performance measured using the Berg Balance Scale in patients with diabetic polyneuropathy.

  Baseline

• Fear of Falling

  To assess the association between serum Neurofilament Light Chain (NfL) levels and fear of falling using the Falls Efficacy Scale-International (FES-I).

  Baseline

Study Arms (2)

Diabetic Polyneuropathy (DPN+)

Participants with Type 2 diabetes mellitus diagnosed with diabetic polyneuropathy based on clinical examination, the Michigan Neuropathy Screening Instrument (MNSI), and electrophysiological evaluation using nerve conduction studies.

Other: Blood Sample Collection and Clinical Assessment

Diabetic Control (DPN-)

Participants with Type 2 diabetes mellitus without clinical or electrophysiological evidence of diabetic polyneuropathy who will serve as the control group.

Other: Blood Sample Collection and Clinical Assessment

Interventions

Blood Sample Collection and Clinical Assessment OTHER

Participants will undergo venous blood sample collection for measurement of serum Neurofilament Light Chain (NfL) levels. Blood samples will be obtained after overnight fasting, centrifuged, and serum samples will be stored at -80°C until analysis. Serum NfL levels will be measured using a validated ELISA-based immunoassay. In addition, clinical assessments including the Michigan Neuropathy Screening Instrument (MNSI), Berg Balance Scale, and Falls Efficacy Scale-International (FES-I) will be performed to evaluate neuropathy severity, balance performance, and fall risk.

Diabetic Control (DPN-); Diabetic Polyneuropathy (DPN+)

Eligibility Criteria

• Age: 30 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults with type 2 diabetes mellitus aged 30-75 years attending a Physical Medicine and Rehabilitation outpatient clinic, including patients with diabetic polyneuropathy and diabetic individuals without neuropathy serving as controls.

You may qualify if:

• For the DPN+ group:
• Presence of diabetic polyneuropathy confirmed by clinical examination, Michigan Neuropathy Screening Instrument (MNSI), and nerve conduction studies
• For the DPN- group:
• Type 2 diabetes mellitus without clinical or electrophysiological evidence of diabetic polyneuropathy

You may not qualify if:

• Neuropathy due to causes other than diabetes (e.g., vitamin B12 deficiency, hypothyroidism, alcohol abuse, chemotherapy) Renal dysfunction (eGFR \< 60 mL/min/1.73 m²) Active infection or malignancy Inflammatory or autoimmune neurological diseases Central nervous system disorders (e.g., stroke, multiple sclerosis) Lumbar radiculopathy or peripheral entrapment neuropathy Severe visual impairment or balance disorders affecting testing Pregnancy Cognitive impairment preventing completion of questionnaires Patients with isolated small fiber neuropathy without electrophysiological evidence of large fiber involvement

Sponsors & Collaborators

• Kanuni Sultan Suleyman Training and Research Hospital: lead

Biospecimen

Retention: SAMPLES WITHOUT DNA

Venous blood samples will be collected from all participants after overnight fasting. Serum will be separated by centrifugation and stored at -80°C until analysis. Serum Neurofilament Light Chain (NfL) levels will be measured using a validated ELISA-based immunoassay. Biospecimens will be used only for the measurement of serum NfL levels related to diabetic polyneuropathy and will not be used for genetic analysis.

MeSH Terms

Conditions

Diabetic Neuropathies

Condition Hierarchy (Ancestors)

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases; Diabetes Complications; Diabetes Mellitus; Endocrine System Diseases

Study Officials

• Zeynep Karakuzu Güngör, M.D

  Kanuni Sultan Süleyman Training and Research Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Zeynep Zeynep Karakuzu Güngör, M.D

CONTACT

Telephone: 905077750375; zeynepkarakuzu@hotmail.com.tr

Zeynep Karakuzu Güngör, M.D

CONTACT

Telephone: 905077750375; zeynepkarakuzu@hotmail.com.tr

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Physical Medicine and Rehabilitation Specialist

Study Record Dates

• First Submitted: March 14, 2026
• First Posted: March 18, 2026
• Study Start: March 25, 2026
• Primary Completion: April 30, 2026
• Study Completion: May 15, 2026
• Last Updated: March 18, 2026

Record last verified: 2026-03