Microvascular DysfunctionNCT07363187
Nailfold Capillaroscopy and Endothelial Biomarkers in Healthcare Workers Exposed to Chronic Low-Dose Ionizing Radiation
An observational study of Microvascular Dysfunction and Endothelial Dysfunction, run by Istanbul Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
Chronic occupational exposure to low-dose ionizing radiation may lead to subclinical endothelial dysfunction and early microvascular alterations in healthcare workers. Nailfold capillaroscopy is a non-invasive method that allows direct visualization of microcirculatory changes. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Microvascular Dysfunction, Endothelial Dysfunction, Occupational Radiation Exposure
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Feb 2026to 1 May 2026
- How long will I take part?
- 1 Day
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The study population will consist of healthcare workers aged 18 to 60 years employed at a tertiary care hospital. The exposed group will include healthcare workers with chronic occupational exposure to low-dose ionizing radiation, while the control group will include healthcare workers without occupational radiation exposure, working in non-radiation-related departments within the same institution. Participants will be recruited on a voluntary basis and will undergo a single study visit including nailfold capillaroscopy, blood sample collection, and completion of demographic and occupational exposure questionnaires.
Who may be able to join
- Healthcare workers aged between 18 and 60 years.
- For the control group: Employment in a healthcare institution with either occupational exposure to low-dose ionizing radiation or no occupational radiation exposure.
- For the exposed group: chronic occupational exposure to ionizing radiation for at least 3 years.
- Willingness and ability to provide written informed consent.
- Ability to comply with study procedures, including nailfold capillaroscopy and blood sample collection.
Who cannot join
- History of cardiovascular disease, cerebrovascular disease, or peripheral vascular disease.
- Presence of systemic diseases that may affect microvascular structure or endothelial function, including diabetes mellitus, uncontrolled hypertension, dyslipidemia, or chronic kidney disease.
- Known autoimmune, connective tissue, or systemic inflammatory diseases (e.g., systemic sclerosis, lupus erythematosus, vasculitis).
- Active infection or acute inflammatory condition at the time of enrollment.
- Use of systemic medications that may affect endothelial function or microcirculation within the past 4 weeks, including vasodilators, antihypertensive agents, statins, antiplatelet or anticoagulant drugs.
- Current smoking or history of smoking within the past 6 months.
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- Pregnancy or breastfeeding.
- History of malignancy or current cancer treatment.
- Previous finger trauma, surgery, or local conditions affecting the nailfold area that may interfere with capillaroscopic evaluation.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Istanbul Training and Research Hospital
Istanbul, 34000
Ayse Esra Koku AKsu, MD, Prof, +905059126069, esraaksu@gmail.com
About this study
Official title: Evaluation of Microvascular Changes by Nailfold Capillaroscopy and Serum ADMA, Von Willebrand Factor, Hs-CRP, and D-dimer Levels in Healthcare Workers Exposed to Chronic Low-Dose Ionizing Radiation
Chronic occupational exposure to low-dose ionizing radiation may lead to subclinical endothelial dysfunction and early microvascular alterations in healthcare workers. Nailfold capillaroscopy is a non-invasive method that allows direct visualization of microcirculatory changes. This observational study aims to evaluate microvascular alterations using nailfold capillaroscopy and to assess their association with serum endothelial and inflammatory biomarkers, including asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer levels. Healthcare workers with chronic low-dose radiation exposure will be compared with non-exposed controls. The study seeks to improve understanding of early vascular effects of occupational radiation exposure.
Read the detailed description
Chronic occupational exposure to low-dose ionizing radiation may result in subclinical endothelial dysfunction and early microvascular alterations, even in the absence of overt clinical disease. Healthcare workers employed in medical departments where ionizing radiation is routinely used are exposed to cumulative radiation over time. Identifying early vascular changes in this population is important for understanding potential long-term cardiovascular risks associated with occupational radiation exposure.
Nailfold capillaroscopy is a non-invasive and reproducible imaging technique that enables direct visualization of the microcirculation and allows detailed assessment of capillary density, morphology, and structural abnormalities. Additionally, circulating endothelial and inflammatory biomarkers such as asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer may reflect endothelial dysfunction, inflammation, and prothrombotic activity at a subclinical level.
This single-center, observational, cross-sectional study will include healthcare workers with chronic occupational exposure to low-dose ionizing radiation and a control group of healthcare workers without radiation exposure from the same institution. Demographic characteristics, occupational exposure duration, and work-related radiation exposure history will be recorded for all participants.
All participants will undergo nailfold capillaroscopy evaluation using standardized assessment criteria, including capillary density, tortuosity, dilatation, dystrophic changes, avascular areas, microhemorrhages, neoangiogenesis, and subpapillary plexus visibility. Venous blood samples will be collected to measure serum ADMA, vWF, hs-CRP, and D-dimer levels using routine laboratory methods and enzyme-linked immunosorbent assay techniques, as appropriate.
The primary objective of this study is to identify microvascular changes detected by nailfold capillaroscopy in healthcare workers exposed to chronic low-dose ionizing radiation. Secondary objectives include evaluating the association between capillaroscopic findings, serum biomarkers, and occupational radiation exposure characteristics. The findings of this study may contribute to improved understanding of early vascular effects of chronic occupational radiation exposure and support the use of nailfold capillaroscopy as a practical screening tool in exposed populations.
- Keywords
- Nailfold capillaroscopy, Microvascular changes, Low-dose ionizing radiation, Occupational radiation exposure, Healthcare workers, Endothelial dysfunction, Inflammation biomarkers, D-dimer, High-sensitivity C-reactive protein, Asymmetric dimethylarginine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Radiation-Exposed Healthcare Workers | Healthcare workers with chronic occupational exposure to low-dose ionizing radiation as part of their routine professional activities in medical departments where radiation is used. | |
| Non-Exposed Control Group | Healthcare workers without occupational exposure to ionizing radiation, working in departments where radiation-based procedures are not used. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Microvascular Changes Assessed by Nailfold Capillaroscopy
Microvascular alterations will be evaluated using nailfold capillaroscopy, including capillary density and morphological abnormalities such as tortuosity, dilatation, elongated capillaries, dystrophic changes, avascular areas, microhemorrhages, neoangiogenesis, and subpapillary plexus visibility. Capillaroscopic findings will be assessed using standardized semi-quantitative scoring criteria
Measured: Baseline (single assessment at study visit
Secondary outcomes (6)
Serum Asymmetric Dimethylarginine (ADMA) Level
Serum levels of asymmetric dimethylarginine (ADMA) will be measured as a marker of endothelial dysfunction.
Measured: Baseline (single assessment at study visit)
Serum von Willebrand Factor (vWF) Level
Serum von Willebrand factor (vWF) levels will be measured to assess endothelial activation and vascular injury.
Measured: Baseline (single assessment at study visit)
Serum High-Sensitivity C-Reactive Protein (hs-CRP) Level
Serum high-sensitivity C-reactive protein (hs-CRP) levels will be measured as a marker of systemic inflammation.
Measured: Baseline (single assessment at study visit)
Serum D-dimer Level
Serum D-dimer levels will be measured to evaluate prothrombotic activity.
Measured: Baseline (single assessment at study visit)
Correlation Between Nailfold Capillaroscopy Scores and Serum Biomarker Levels
The correlation between nailfold capillaroscopy findings and serum biomarker levels will be evaluated. Nailfold capillaroscopy parameters, including capillary density score and semi-quantitative morphological scores (tortuosity, dilatation, dystrophic changes, avascular areas, microhemorrhages, and neoangiogenesis), assessed using standardized nailfold capillaroscopy evaluation criteria, will be correlated with serum concentrations of asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer measured by laboratory assays. Correlation analysis will be performed to assess the relationship between microvascular structural alterations and biochemical markers of endothelial dysfunction, inflammation, and prothrombotic activity.
Measured: Baseline (cross-sectional analysis)
Correlation Between Occupational Radiation Exposure and Microvascular and Serum Biomarker Measurements
The correlation between occupational radiation exposure and microvascular and biochemical parameters will be evaluated. Occupational radiation exposure will be assessed using self-reported work history, including duration of employment in radiation-related medical departments (years of exposure). Microvascular changes will be assessed by nailfold capillaroscopy using standardized semi-quantitative scoring systems, including capillary density score and morphological scores (tortuosity, dilatation, dystrophic changes, avascular areas, microhemorrhages, and neoangiogenesis). Biochemical parameters will include serum concentrations of asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer, measured by laboratory assays. Correlation analyses will be performed to evaluate the relationship between occupational radiation exposure duration and microvascular or serum biomarker measurements.
Measured: Baseline (cross-sectional analysis)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2026
- Study start1 Feb 2026 (estimated)
- Primary completion1 Apr 2026 (estimated)
- Study completion1 May 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Microvascular DysfunctionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 90 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Istanbul Training and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Elif Banu Yildiran, Istanbul Training and Research Hospital
- Investigators
- Elif Banu Yildiran, MD, Principal investigator, Istanbul Training and Research Hospital, Dept. of DermatologyDuygu Yamen, MD, Study director, Istanbul Training and Research Hospital, Dept. of DermatologyAyse Esra Koku Aksu, MD, Prof, Study chair, Istanbul Training and Research Hospital, Dept. of Dermatology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07363187
- Sponsor's protocol ID
- SBU-IEAH-EC274
- Status last verified
- Jan 2026
- First submitted
- 7 Jan 2026
- Last updated
- 26 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 26 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Microvascular Changes by Nailfold Capillaroscopy and Serum ADMA, Von Willebrand Factor, Hs-CRP, and D-dimer Levels in Healthcare Workers Exposed to Chronic Low-Dose Ionizing Radiation
- ClinicalTrials.gov ID
- NCT07363187
- Acronym / sponsor ID
- SBU-IEAH-EC274
- Keywords
- Nailfold capillaroscopy, Microvascular changes, Low-dose ionizing radiation, Occupational radiation exposure, Healthcare workers, Endothelial dysfunction, Inflammation biomarkers, D-dimer
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- Istanbul Training and Research HospitalOther government
- Study start
- 1 Feb 2026 (estimated)
- Primary completion
- 1 Apr 2026 (estimated)
- Study completion
- 1 May 2026 (estimated)
- First posted
- 23 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Chronic occupational exposure to low-dose ionizing radiation may lead to subclinical endothelial dysfunction and early microvascular alterations in healthcare workers. Nailfold capillaroscopy is a non-invasive method that allows direct visualization of microcirculatory changes. This observational study aims to evaluate microvascular alterations using nailfold capillaroscopy and to assess their association with serum endothelial and inflammatory biomarkers, including asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer levels. Healthcare workers with chronic low-dose radiation exposure will be compared with non-exposed controls. The study seeks to improve understanding of early vascular effects of occupational radiation exposure.
Detailed description
Chronic occupational exposure to low-dose ionizing radiation may result in subclinical endothelial dysfunction and early microvascular alterations, even in the absence of overt clinical disease. Healthcare workers employed in medical departments where ionizing radiation is routinely used are exposed to cumulative radiation over time. Identifying early vascular changes in this population is important for understanding potential long-term cardiovascular risks associated with occupational radiation exposure.
Nailfold capillaroscopy is a non-invasive and reproducible imaging technique that enables direct visualization of the microcirculation and allows detailed assessment of capillary density, morphology, and structural abnormalities. Additionally, circulating endothelial and inflammatory biomarkers such as asymmetric dimethylarginine (ADMA), von Willebrand factor (vWF), high-sensitivity C-reactive protein (hs-CRP), and D-dimer may reflect endothelial dysfunction, inflammation, and prothrombotic activity at a subclinical level.
This single-center, observational, cross-sectional study will include healthcare workers with chronic occupational exposure to low-dose ionizing radiation and a control group of healthcare workers without radiation exposure from the same institution. Demographic characteristics, occupational exposure duration, and work-related radiation exposure history will be recorded for all participants.
All participants will undergo nailfold capillaroscopy evaluation using standardized assessment criteria, including capillary density, tortuosity, dilatation, dystrophic changes, avascular areas, microhemorrhages, neoangiogenesis, and subpapillary plexus visibility. Venous blood samples will be collected to measure serum ADMA, vWF, hs-CRP, and D-dimer levels using routine laboratory methods and enzyme-linked immunosorbent assay techniques, as appropriate.
The primary objective of this study is to identify microvascular changes detected by nailfold capillaroscopy in healthcare workers exposed to chronic low-dose ionizing radiation. Secondary objectives include evaluating the association between capillaroscopic findings, serum biomarkers, and occupational radiation exposure characteristics. The findings of this study may contribute to improved understanding of early vascular effects of chronic occupational radiation exposure and support the use of nailfold capillaroscopy as a practical screening tool in exposed populations.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Radiation-Exposed Healthcare Workers | – | –Healthcare workers with chronic occupational exposure to low-dose ionizing radiation as part of their routine professional activities in medical departments where radiation is used. |
| Non-Exposed Control Group | – | –Healthcare workers without occupational exposure to ionizing radiation, working in departments where radiation-based procedures are not used. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The study population will consist of healthcare workers aged 18 to 60 years employed at a tertiary care hospital. The exposed group will include healthcare workers with chronic occupational exposure to low-dose ionizing radiation, while the control group will include healthcare workers without occupational radiation exposure, working in non-radiation-related departments within the same institution. Participants will be recruited on a voluntary basis and will undergo a single study visit including nailfold capillaroscopy, blood sample collection, and completion of demographic and occupational exposure questionnaires.
Key inclusion criteria (5 listed)
- Healthcare workers aged between 18 and 60 years.
- For the control group: Employment in a healthcare institution with either occupational exposure to low-dose ionizing radiation or no occupational radiation exposure.
- For the exposed group: chronic occupational exposure to ionizing radiation for at least 3 years.
- Willingness and ability to provide written informed consent.
- Ability to comply with study procedures, including nailfold capillaroscopy and blood sample collection.
Key exclusion criteria (9 listed)
- History of cardiovascular disease, cerebrovascular disease, or peripheral vascular disease.
- Presence of systemic diseases that may affect microvascular structure or endothelial function, including diabetes mellitus, uncontrolled hypertension, dyslipidemia, or chronic kidney disease.
- Known autoimmune, connective tissue, or systemic inflammatory diseases (e.g., systemic sclerosis, lupus erythematosus, vasculitis).
- Active infection or acute inflammatory condition at the time of enrollment.
- Use of systemic medications that may affect endothelial function or microcirculation within the past 4 weeks, including vasodilators, antihypertensive agents, statins, antiplatelet or anticoagulant drugs.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Microvascular Changes Assessed by Nailfold Capillaroscopy
Time frame: Baseline (single assessment at study visit
Microvascular alterations will be evaluated using nailfold capillaroscopy, including capillary density and morphological abnormalities such as tortuosity, dilatation, elongated capillaries, dystrophic changes, avascular areas, microhemorrhages, neoangiogenesis, and subpapillary plexus visibility. Capillaroscopic findings will be assessed using standardized semi-quantitative scoring criteria
6 secondary outcomes
Serum Asymmetric Dimethylarginine (ADMA) Level
Time frame: Baseline (single assessment at study visit)
Serum von Willebrand Factor (vWF) Level
Time frame: Baseline (single assessment at study visit)
Serum High-Sensitivity C-Reactive Protein (hs-CRP) Level
Time frame: Baseline (single assessment at study visit)
Serum D-dimer Level
Time frame: Baseline (single assessment at study visit)
Correlation Between Nailfold Capillaroscopy Scores and Serum Biomarker Levels
Time frame: Baseline (cross-sectional analysis)
Correlation Between Occupational Radiation Exposure and Microvascular and Serum Biomarker Measurements
Time frame: Baseline (cross-sectional analysis)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Jan 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Elif Banu Yildiran, MD principal investigator
Istanbul Training and Research Hospital, Dept. of Dermatology
Duygu Yamen, MD study director
Istanbul Training and Research Hospital, Dept. of Dermatology
Ayse Esra Koku Aksu, MD, Prof study chair
Istanbul Training and Research Hospital, Dept. of Dermatology
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Microvascular Dysfunction and Endothelial Dysfunction, run by Istanbul Training and Research Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 26 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Elif Banu Yildiran, MD (+905303552144, elifbanuyildiran@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Microvascular Changes Assessed by Nailfold Capillaroscopy (time frame: Baseline (single assessment at study visit). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Jan 2026.