Serum Endocan, Alarin, and Galanin-Like Peptide Levels in Diabetic Retinopathy

February 20, 2026 updated by: Sinem Keser, Elazıg Fethi Sekin Sehir Hastanesi

Association of Serum Endocan, Alarin, and Galanin-Like Peptide Levels With Diabetic Retinopathy Stages and Optical Coherence Tomography (OCT) Findings

This prospective cross-sectional study aims to evaluate the association between serum endocan, alarin, and galanin-like peptide levels and the stages of diabetic retinopathy (DR), as well as their relationship with optical coherence tomography (OCT) findings.

A total of 120 participants will be included: 30 patients without diabetic retinopathy, 30 with non-proliferative diabetic retinopathy, 30 with proliferative diabetic retinopathy, and 30 healthy control subjects. In addition to routine preoperative blood sampling, an additional 5 mL of venous blood will be collected for biomarker analysis using ELISA. Macular and peripapillary retinal nerve fiber layer measurements will be obtained using OCT. Serum biomarker levels will be compared across DR stages and analyzed for correlation with OCT parameters.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

90

Phase

  • Not Applicable

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)
    • Elaziğ
      • Elâzığ, Elaziğ, Turkey (Türkiye)
        • Fethi Sekin City 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

No

Description

Inclusion Criteria:

  • Adults aged 40 to 70 years.
  • Diagnosis of diabetes mellitus (for diabetic groups).
  • For control group: absence of diabetes mellitus and no retinal or optic nerve pathology.

Exclusion Criteria:

  • Presence of systemic or ocular inflammatory disease.
  • Any ocular disease other than diabetic retinopathy that may affect the retina or optic nerve.

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

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Diabetes Mellitus Without Retinopathy
Patients diagnosed with diabetes mellitus without clinical evidence of diabetic retinopathy. Participants will undergo OCT examination and additional venous blood sampling for biomarker analysis.
Procedure: Venous Blood Sampling
Collection of 5 mL of venous blood in addition to routine preoperative sampling for the measurement of serum endocan, alarin, and galanin-like peptide levels using ELISA.
Procedure: Optical Coherence Tomography (OCT)
Non-invasive optical coherence tomography imaging of the macula and peripapillary retinal nerve fiber layer using a Canon OCT device for structural retinal assessment.
Other: Non-Proliferative Diabetic Retinopathy (NPDR)
Patients with clinically diagnosed non-proliferative diabetic retinopathy who will undergo OCT examination and additional venous blood sampling for serum biomarker measurement.
Procedure: Venous Blood Sampling
Collection of 5 mL of venous blood in addition to routine preoperative sampling for the measurement of serum endocan, alarin, and galanin-like peptide levels using ELISA.
Procedure: Optical Coherence Tomography (OCT)
Non-invasive optical coherence tomography imaging of the macula and peripapillary retinal nerve fiber layer using a Canon OCT device for structural retinal assessment.
Other: Proliferative Diabetic Retinopathy (PDR)
Patients with clinically diagnosed proliferative diabetic retinopathy who will undergo OCT examination and additional venous blood sampling for serum biomarker analysis.
Procedure: Venous Blood Sampling
Collection of 5 mL of venous blood in addition to routine preoperative sampling for the measurement of serum endocan, alarin, and galanin-like peptide levels using ELISA.
Procedure: Optical Coherence Tomography (OCT)
Non-invasive optical coherence tomography imaging of the macula and peripapillary retinal nerve fiber layer using a Canon OCT device for structural retinal assessment.
Other: Healthy Control Group
Age-matched control participants without diabetes or retinal pathology who will undergo OCT examination and venous blood sampling for comparative biomarker evaluation.
Procedure: Venous Blood Sampling
Collection of 5 mL of venous blood in addition to routine preoperative sampling for the measurement of serum endocan, alarin, and galanin-like peptide levels using ELISA.
Procedure: Optical Coherence Tomography (OCT)
Non-invasive optical coherence tomography imaging of the macula and peripapillary retinal nerve fiber layer using a Canon OCT device for structural retinal assessment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Serum Endocan Level
Time Frame: At baseline (preoperative blood sampling)
Serum endocan concentration measured using ELISA and compared across diabetic retinopathy stages.
At baseline (preoperative blood sampling)
Serum Alarin Level
Time Frame: At baseline
Serum alarin concentration measured by ELISA and analyzed according to diabetic retinopathy severity.
At baseline
Serum Galanin-Like Peptide Level
Time Frame: At baseline
Serum galanin-like peptide concentration measured using ELISA and compared between study groups.
At baseline

Collaborators and Investigators

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

Sponsor

Elazıg Fethi Sekin Sehir Hastanesi

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)

January 30, 2026

Primary Completion (Actual)

February 1, 2026

Study Completion (Actual)

February 18, 2026

Study Registration Dates

First Submitted

February 20, 2026

First Submitted That Met QC Criteria

February 20, 2026

First Posted (Actual)

February 25, 2026

Study Record Updates

Last Update Posted (Actual)

February 25, 2026

Last Update Submitted That Met QC Criteria

February 20, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EFSH-NIEC-2025-10-15

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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