Iris Color and Day-Night Changes in the Sympathovagal Ratio

March 7, 2023 updated by: Şahbender Koç, Ankara Ataturk Sanatorium Training and Research Hospital
Iris melanocytes are innervated by parasympathetic and sympathetic nerve endings. Light affects autonomic nervous system activity via the retino-hypothalamic pathway. The hypothesis that the day-to-night variations in the sympatovagal ratio (LF/HF) may differ among individuals with different brown iris patterns was tested.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

A total of 621 healthy adults, aged between 16 and 50, with brown eyes and not diagnosed with a disease that might affect the autonomous nerve system were included in the study. A digital camera was used to acquire iris photos. Subjects were grouped into iris color groups (2-0 bg, 1-0 bg, 1-1 db, 1-1 lb, 2-0 b, and 1-0 b). Iris photos were analyzed with Picture Color Analyzer RBG software. The Central/Peripheral (R/RGB) ratio was used for objective distinction between the groups. Using 24-h Holter ECG monitoring, the change in the sympathovagal ratio from day (between 07:00 and 23:00 hrs) to night (between 23:00 and 07:00 hrs) was determined with the formula [(Day - Night) LF/HF)/Day LF/HF].

Study Type

Observational

Enrollment (Actual)

621

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

16 years to 50 years (Child, Adult)

Accepts Healthy Volunteers

N/A

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

A total of 650 healthy individuals between the ages of 16 and 50 who applied for cardiac examination and had normal findings were recruited for the study.

Description

Inclusion Criteria:

A total of 650 healthy individuals between the ages of 16 and 50 .

Exclusion Criteria:

Diseases that could affect the autonomic nervous system; Obesity Obstructive sleep apnea syndrome Hypertension Diabetes mellitus Atrial fibrillation Coronary disease Heart failure Goiter, etc.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
2-0 darkbown-green (2-0 bg)
Those with distinctively dark brown in the central area, slightly green in the peripheral area,
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
1-0 lightbrown-green (1-0 bg).
Those with slightly dark brown in the central area and green in the peripheral area,
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
dark brown (1-1 db)
Eyes with the same color structure in the central iris and the peripheral iris.
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
light brown (1-1 lb)
Eyes with the same color structure in the central iris and the peripheral iris.
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
dark brown (2-0 b)
Those with distinctively dark brown in the central iris area compared to the periphery .
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
slightly dark brown (1-0 b)
Those with slightly dark brown (1-0 b) in the central iris area compared to the periphery .
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
LF/HF ratio
Time Frame: one week
low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, 0.16-0.4 Hz) measurements were taken from day and night changes in the heart rate by using the frequency-domain analysis method.
one week

Collaborators and Investigators

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

Sponsor

Ankara Ataturk Sanatorium 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 (Actual)

May 5, 2016

Primary Completion (Actual)

May 5, 2022

Study Completion (Actual)

June 1, 2022

Study Registration Dates

First Submitted

February 27, 2023

First Submitted That Met QC Criteria

February 27, 2023

First Posted (Actual)

March 8, 2023

Study Record Updates

Last Update Posted (Estimate)

March 9, 2023

Last Update Submitted That Met QC Criteria

March 7, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1099/9.3.2016

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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