Effects of Afternoon and Evening Light on Teenagers' Melatonin Levels, Alertness, Sleepiness and Sleep

NCT05483296 | Completed DMC

• 1 other identifier: 2022-00432
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

Many teenagers are familiar with this: on school days, they have to get up early; during the day, they hardly get any light exposure; in the evening, they go to bed late - and are then tired at school the next day! Around the world, teenagers are sleep deprived, with studies suggesting that almost half (\~45%) suffer from inadequate sleep. Previous investigations have shown that people's sleep-wake rhythm is related to the light conditions that they are exposed to during the day and at night. However, little is known about how different light levels in the afternoon can modulate teenagers' sleep and their bodily responses to light in the late evening. Therefore, the investigators aim to study which lighting conditions have a favourable effect on these aspects and how the potentially harmful effects of light at night can be prevented.

Conditions

Healthy; Teenager; Healthy Lifestyle

Keywords

melatonin; polysomnography; EEG; sleep; afternoon light; pupil size; evening light

Outcome Measures

Primary Outcomes (1)

• Salivary melatonin

  Salivary melatonin. Saliva samples (\>1 mL) will be taken from the participants every 30 Minutes using Salivettes. The Salivettes will be centrifuged, the cotton part removed and immediately frozen at -20°C. At a later point, melatonin \[in pg\] will be determined in these samples by double-antibody radioimmunoassay (RIA). To quantify melatonin suppression, the analytic team will calculate the area under the curve (AUC) for each laboratory condition.

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

Secondary Outcomes (9)

• Sleep Onset Latency (PSG-derived)

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Slow wave activity (PSG-derived)

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Sleep stages (PSG-derived)

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Subjective sleepiness

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Vigilant attention

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

Other Outcomes (6)

• Ambulant light history.

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Actigraphy

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

• Visual comfort & well-being

  Through study completion, estimated 1.5 years (within 3 weeks for each participant)

Study Arms (6)

Crossover sequence 1: Dim, Moderate, Bright

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \<10 lx. In the second experimental session, they receive an intensity of \~100 lx, and in the third experimental session, they receive an intensity of \>1000 lx.

Other: Dim light condition; Other: Moderate light condition; Other: Bright light condition

Crossover sequence 2: Dim, Bright, Moderate

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \<10 lx. In the second experimental session, they receive an intensity of \>1000 lx, and in the third experimental session, they receive an intensity of \~100 lx.

Other: Dim light condition; Other: Moderate light condition; Other: Bright light condition

Crossover sequence 3: Moderate, Dim, Bright

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \~100 lx. In the second experimental session, they receive an intensity of \<10 lx, and in the third experimental session, they receive an intensity of \>1000 lx.

Crossover sequence 4: Moderate, Bright, Dim

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \~100 lx. In the second experimental session, they receive an intensity of \>1000 lx, and in the third experimental session, they receive an intensity of \<10 lx.

Crossover sequence 5: Bright, Moderate, Dim

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \>1000 lx. In the second experimental session, they receive an intensity of \~100 lx, and in the third experimental session, they receive an intensity of \<10 lx.

Crossover sequence 6: Bright, Dim, Moderate

EXPERIMENTAL

All participants will go through all three light conditions in the three experiment sessions: They will receive white fluorescent overhead light (given in melanopic EDI at eye level) as the 4h afternoon light intervention. In the first experimental session, they receive an intensity of \>1000 lx. In the second experimental session, they receive an intensity of \<10 lx, and in the third experimental session, they receive an intensity of \~100 lx.

Interventions

Dim light condition OTHER

During the "Dim" light condition, the four-hour afternoon light exposure at the participants' eye level will be dim (\<5 lx melanopic EDI). In the 4.5-hour evening light exposure, this will constitute a light intensity of \~100 lx melanopic EDI at the participants' eye level.

Crossover sequence 1: Dim, Moderate, Bright; Crossover sequence 2: Dim, Bright, Moderate

Moderate light condition OTHER

During the "Moderate" light condition, the four-hour afternoon light exposure at the participants' eye level will be dim (\~100 lx melanopic EDI). In the 4.5-hour evening light exposure, this will constitute a light intensity of \~100 lx melanopic EDI at the participants' eye level.

Crossover sequence 1: Dim, Moderate, Bright; Crossover sequence 2: Dim, Bright, Moderate

Bright light condition OTHER

During the "Bright" light condition, the four-hour afternoon light exposure at the participants' eye level will be dim (\>1000 lx melanopic EDI). In the 4.5-hour evening light exposure, this will constitute a light intensity of \~100 lx melanopic EDI at the participants' eye level.

Crossover sequence 1: Dim, Moderate, Bright; Crossover sequence 2: Dim, Bright, Moderate

Eligibility Criteria

• Age: 14 Years - 17 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• Healthy
• Capable of judgment
• Normal BMI (Age-related Body-Mass-Index Percentile \> P3 \& \< P97; approx. corresponding to 28.5 ≥ BMI ≤ 16)
• Signed consent form of participants
• Signed consent form of a legal representative

You may not qualify if:

• Pregnancy or breastfeeding (only female)
• Current participation in other clinical trials
• Extreme chronotype (Extreme early or late chronotype/mid sleep time: mid-sleep time \< 1:00 / \> 7:00)
• Extremely short or long sleep durations during school- or work days (\< 6 hours \> 11 hours)
• Sleep disorders
• High myopia (\< -6 diopters)
• High hyperopia (\> +6 diopters)
• Non-normal best-corrected visual acuity (BCVA \< 0.5 \[20/40\])
• General health concerns or disorders, including heart and cardiovascular, neurological, nephrological, endocrinological, and psychiatric conditions
• Ophthalmological or optometric conditions
• Medication impacting visual, neuroendocrine, sleep, and circadian physiology
• Drug and alcohol use (urinary drug screening \& breathalyzer test)
• Non-compliance with sleep-wake times: \>1 deviation from ±60 minute window sleep and wake-up time
• Non-compliance with caffeine intake (\> 1 times caffeine intake)
• Transmeridian travel (\>2 time zones) \<1 month prior to the first session of the study

Sponsors & Collaborators

• University Psychiatric Clinics Basel: lead

Study Sites (1)

Psychiatric University Clinics (UPK), Centre for Chronobiology

Basel, Canton of Basel-City, 4002, Switzerland

Location

Related Publications (9)

• Galland BC, Short MA, Terrill P, Rigney G, Haszard JJ, Coussens S, Foster-Owens M, Biggs SN. Establishing normal values for pediatric nighttime sleep measured by actigraphy: a systematic review and meta-analysis. Sleep. 2018 Apr 1;41(4). doi: 10.1093/sleep/zsy017.

  PMID: 29590464 BACKGROUND

• Hagenauer MH, Perryman JI, Lee TM, Carskadon MA. Adolescent changes in the homeostatic and circadian regulation of sleep. Dev Neurosci. 2009;31(4):276-84. doi: 10.1159/000216538. Epub 2009 Jun 17.

  PMID: 19546564 BACKGROUND

• Lo JC, Lee SM, Lee XK, Sasmita K, Chee NIYN, Tandi J, Cher WS, Gooley JJ, Chee MWL. Sustained benefits of delaying school start time on adolescent sleep and well-being. Sleep. 2018 Jun 1;41(6):zsy052. doi: 10.1093/sleep/zsy052.

  PMID: 29648616 BACKGROUND

• Santhi N, Ball DM. Applications in sleep: How light affects sleep. Prog Brain Res. 2020;253:17-24. doi: 10.1016/bs.pbr.2020.05.029. Epub 2020 Jul 25.

  PMID: 32771123 BACKGROUND

• Akerstedt T, Gillberg M. Subjective and objective sleepiness in the active individual. Int J Neurosci. 1990 May;52(1-2):29-37. doi: 10.3109/00207459008994241.

  PMID: 2265922 BACKGROUND

• Gabel V, Kass M, Joyce DS, Spitschan M, Zeitzer JM. Auditory psychomotor vigilance testing in older and young adults: a revised threshold setting procedure. Sleep Breath. 2019 Sep;23(3):1021-1025. doi: 10.1007/s11325-019-01859-7. Epub 2019 May 8.

  PMID: 31069648 BACKGROUND

• Spitschan M, Woelders T. The Method of Silent Substitution for Examining Melanopsin Contributions to Pupil Control. Front Neurol. 2018 Nov 27;9:941. doi: 10.3389/fneur.2018.00941. eCollection 2018.

  PMID: 30538662 BACKGROUND

• Parrott AC, Hindmarch I. The Leeds Sleep Evaluation Questionnaire in psychopharmacological investigations - a review. Psychopharmacology (Berl). 1980;71(2):173-9. doi: 10.1007/BF00434408.

  PMID: 6777817 BACKGROUND

• Chellappa SL, Munch M, Blatter K, Knoblauch V, Cajochen C. Does the circadian modulation of dream recall modify with age? Sleep. 2009 Sep;32(9):1201-9. doi: 10.1093/sleep/32.9.1201.

  PMID: 19750925 BACKGROUND

Study Officials

• Christian Cajochen, PhD

  Centre for Chronobiology, University Psychiatric Clinics Basel, Basel, Switzerland

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Entirely blinding the differences between the experiment's light conditions is unattainable (for both participants and experimenters) because of the visibly perceivable differences in brightness between them. However, the melatonin and objective EEG measurements should not be significantly affected by any expectancy effects. Participants will not be told the expected effects of the different light exposure conditions to minimise the expectancy effects for behavioural measures (i.e., PVT) and subjective measurements. Information on the hypothesized outcomes will be withheld from the volunteers and study helpers until after completing all sessions. During the analysis, light intensity conditions and participant IDs will be coded to withhold information from the analytic team about the light intensity.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: NETWORK
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator/ Sponsor-Investigator

Model Details: The protocol is a full within-subject trial (cross-over). All participants will conduct three 18-hour experiment sessions and go through the same protocol except for the sequence of the experiment sessions (counter-balanced and randomised).

Study Record Dates

• First Submitted: July 25, 2022
• First Posted: August 2, 2022
• Study Start: September 22, 2022
• Primary Completion: June 20, 2023
• Study Completion: June 20, 2023
• Last Updated: March 30, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will share

Locations

CH (1)