A Study on the Changes of the Biological Rhythm by Display Image Modulation

Effects of Smartphone Use at Night with Light Emitting Diode Display With and Without Blue Light in Healthy Adults: A Randomized, Double-blind, Cross-over, Placebo-controlled Comparison

Study Overview

• Status: Completed
• Conditions: Circadian Rhythm Phase Shift
• Intervention / Treatment: Device: smartphone display

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

(1) Healthy males 20-40 years of age who understood the study procedure and agreed to participate after being fully informed about the study were included.

Exclusion Criteria:

1. psychiatric diseases according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria;15
2. cognitive or neurological disorders;
3. alcohol or substance abuse;
4. unstable or serious medical illness;
5. current use of psychoactive mediations including antidepressants, anxiolytics, neuroleptics, anticonvulsants, hypnotics, or stimulant medications;
6. primary sleep disorder;
7. habitual sleep onset earlier than 21:00 or later than 24:00;
8. shift worker;
9. travel across more than two time zones within 90 days of the study; and
10. ophthalmologic disease during the study period.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: LED with bluelight; Two types of smartphone were used. One type had a conventional LED display with the full range of blue light. The LED in the other type newly developed by Samsung Display was suppressed for the blue light portion of the spectrum (wavelength 450 ~ 470 nm). The smartphones were indistinguishable from each other with the naked eye, because other wavelengths mimicked blue light in the suppressed LED.	Device: smartphone display
Experimental: LED without bluelight; Two types of smartphone were used. One type had a conventional LED display with the full range of blue light. The LED in the other type newly developed by Samsung Display was suppressed for the blue light portion of the spectrum (wavelength 450 ~ 470 nm). The smartphones were indistinguishable from each other with the naked eye, because other wavelengths mimicked blue light in the suppressed LED.	Device: smartphone display

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes of serum melatonin	serum melatonin levels were measured every 60 min from 7:00 PM on day 1 to 8:00 AM on day 2, from 7:00 PM on day 2 to 8:00 AM on day 3, and from 7:00 PM to 11:00 PM on day 3 for 3 days.
Changes of serum cortisol	cortisol levels were measured every 120 min from 7:00 PM on day 1 to 8:00 AM on day 2, from 7:00 PM on day 2 to 8:00 AM on day 3, and from 7:00 PM to 11:00 PM on day 3 for 3 days.
Changes of body temperature	body temperature was measured every 120 min from 7:00 PM on day 1 to 8:00 AM on day 2, from 7:00 PM on day 2 to 8:00 AM on day 3, and from 7:00 PM to 11:00 PM on day 3 for 3days.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
profile of mood states(POMS)	Mood was measured using the POMS,17 a well-validated self-report measure of mood states.	day 1,3
Epworth Sleepiness Scale(ESS)	ESS18 is comprised of eight questions that query the subject's likelihood of dozing off or falling asleep in a particular situation that is commonly met in daily life.	day 1,3
Fatigue severity scale(FSS)	The FSS20 is composed of 9 statements (items) that describe fatigue symptoms. Respondents select the most relevant level of agreement over the last week on a 7-point scale (1 strongly disagree; 7 strongly agree).	day 1,3
continuous performance test(CPT)	Integrated visual-auditory CPTs were performed at days 1 and 3 by a psychologist who was an expert on cognitive tests	day1,3

Collaborators and Investigators

• Sponsor: Samsung Medical Center

Study record dates

Study Major Dates

• Study Start: August 1, 2013
• Primary Completion (Actual): January 1, 2014

Study Registration Dates

• First Submitted: January 28, 2016
• First Submitted That Met QC Criteria: February 18, 2016
• First Posted (Estimate): February 24, 2016

Study Record Updates

• Last Update Posted (Estimate): February 24, 2016
• Last Update Submitted That Met QC Criteria: February 18, 2016
• Last Verified: August 1, 2013

More Information

Terms related to this study

• Other Study ID Numbers: 2013-08-072