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Cited by 248Circadian rhythm and melatoninHypothalamic control of reproductive hormonesSleep and related disorders

Increased Sensitivity of the Circadian System to Light in Early/Mid-Puberty

Open access
Crowley, Stephanie J., Cain, Sean W., Burns, Angus C., Acebo, Christine, Carskadon, Mary A.·2015·The Journal of Clinical Endocrinology & Metabolism
DOI 10.1210/jc.2015-2775PMC PMC4702443
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Abstract

CONTEXT: Late adolescence is marked by a delay in sleep timing, which is partly driven by a delay shift of the circadian timing system. This study examined whether the sensitivity of the circadian system to light-the primary entraining stimulus to the circadian system-differs between pre- to mid-pubertal and late to postpubertal adolescents. OBJECTIVE: The study was designed to determine the influence of puberty on the sensitivity of the circadian system to light in humans. METHODS: Melatonin suppression to low and moderate light levels was assessed in 38 pre- to mid-pubertal (9.1-14.7 years) and 29 late to postpubertal (11.5-15.9 years) adolescents. They received 1 hour of four light levels on consecutive nights: approximately 0.1 (near-dark baseline condition), 15, 150, and 500 lux. One group received evening light beginning at 11:00 pm (n = 39); a second group received morning light beginning at 3:00 am (n = 28). Salivary melatonin was sampled every 30 minutes. Melatonin suppression for 15, 150, and 500 lux was calculated relative to unsuppressed baseline levels in the 0.1 lux setting, within individuals. RESULTS: The pre- to mid-pubertal group showed significantly greater melatonin suppression to 15 lux (9.2 ± 20.5%), 150 lux (26.0 ± 17.7%), and 500 lux (36.9 ± 11.4%) during evening light exposure compared to the late to postpubertal group (-5.3 ± 17.7%, 12.5 ± 17.3%, and 23.9 ± 21.7%, respectively; P < .05). No significant differences were seen between developmental groups in morning melatonin suppression. CONCLUSION: These results indicate support for a greater sensitivity to evening light in early pubertal children. The increased sensitivity to light in younger adolescents suggests that exposure to evening light could be particularly disruptive to sleep regulation for this group.

AI snapshot

Written from the paper’s full text.

TL;DR

In adolescents, the circadian system appears more sensitive to evening light in early/mid-puberty than in late/post-puberty, as shown by greater melatonin suppression to low and moderate evening light. Morning light did not produce significant puberty-group differences in melatonin suppression.

Key findings

  • During evening light, pre/mid-pubertal adolescents showed significantly greater melatonin suppression than late/post-pubertal adolescents at 15 lux (9.2 ± 20.5% vs −5.3 ± 17.7%), 150 lux (26.0 ± 17.7% vs 12.5 ± 17.3%), and 500 lux (36.9 ± 11.4% vs 23.9 ± 21.7%; P < .05).
  • During morning light, no significant puberty-group differences were found for melatonin suppression measured by AUC at any light condition; a trend toward greater suppression at 500 lux after 30 minutes was seen in the pre/mid-pubertal group (P = .06).
  • No statistically significant differences in melatonin suppression were found between males and females for any evening or morning light condition (P > .05).
  • The circadian timing of light exposure did not differ significantly between puberty groups for evening or morning light (P > .05), indicating suppression differences were not due to systematic differences in biological time of exposure.

Methods

  • A total of 67 adolescents aged 9.1–15.9 years completed the study; puberty groups were formed by Tanner stage: pre/mid-puberty = Tanner 1–3, late/post-puberty = Tanner 4–5. Participants were assigned to an evening light group (n = 39) or morning light group (n = 28) based on availability.
  • Over four consecutive laboratory nights, participants received 1-hour light exposures at approximately 0.1 lux (near-dark baseline), 15 lux, 150 lux, and 500 lux; evening exposure began at 11:00 PM and morning exposure began at 3:00 AM. Salivary melatonin was sampled every 30 minutes.
  • Melatonin suppression was calculated within individuals relative to the 0.1 lux baseline using area under the curve (AUC) and absolute melatonin levels at 30 and 60 minutes after light exposure; independent samples t tests compared puberty groups.

Limitations

  • The paper states that it measured melatonin suppression rather than phase shifting, so it cannot confirm that pubertal differences in phase delays occur; further studies are needed to examine phase shifts.
  • The paper states that the lack of significant morning-light differences may have resulted from a lack of statistical power.
  • Evident from the text: assignment to evening versus morning light groups was based on participant availability rather than randomization, and group sizes were modest.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1210/jc.2015-2775

Cites

Statistics

Nothing to recompute.

Claims the paper makes

0 of 16 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    At 60 minutes of morning light exposure, pubertal groups did not differ in melatonin suppression for any light level.

    “At 60 minutes, pubertal groups did not differ in melatonin suppression for any light level.”
    Quote in the paperNot a substantial claim
  • Findingown data

    At 30 minutes of evening light exposure, pre/midpubertal adolescents showed significantly greater average melatonin suppression at 500 lux than late/postpubertal adolescents.

    “At 30 minutes, the pre/ midpuberty group demonstrated significantly greater av-erage suppression in both the 15 lux and 500 lux conditions (P Ͻ .05) and tended to show greater suppression at 150 lux (P ϭ .06)when compared to the late/ postpuberty group.”
    Quote in the paperSubstantial claim
  • Findingown data

    Evening light at 15 lux produced significantly greater melatonin suppression (AUC) in pre/midpubertal adolescents than in late/postpubertal adolescents.

    “The pre-to mid-pubertal group showed significantly greater melatonin suppression to 15 lux (9.2 Ϯ 20.5%), 150 lux (26.0 Ϯ 17.7%), and 500 lux (36.9 Ϯ 11.4%) during evening light exposure compared to the late to postpubertal group (Ϫ5.3 Ϯ 17.7%, 12.5 Ϯ 17.3%, and 23.9 Ϯ 21.7%, respectively; P Ͻ .05).”
    • Also stated in: § Melatonin suppression · plain
      “Exposure to all light levels (15, 150, and 500 lux) produced significantly greater melatonin suppression in the pre/midpuberty group compared to the late/postpuberty group (P Ͻ .05).”
    Quote in the paperSubstantial claim
  • Findingown data

    At 60 minutes of evening light exposure, pre/midpubertal adolescents exhibited significantly greater average melatonin suppression at all light conditions (15, 150, and 500 lux) than late/postpubertal adolescents.

    “At 60 minutes, the pre/midpuberty group exhibited significantly greater average suppression at all light conditions (P Ͻ .05)when compared to the late/postpuberty group.”
    Quote in the paperSubstantial claim
  • Findingown data

    Evening light at 150 lux produced significantly greater melatonin suppression (AUC) in pre/midpubertal adolescents than in late/postpubertal adolescents.

    “The pre-to mid-pubertal group showed significantly greater melatonin suppression to 15 lux (9.2 Ϯ 20.5%), 150 lux (26.0 Ϯ 17.7%), and 500 lux (36.9 Ϯ 11.4%) during evening light exposure compared to the late to postpubertal group (Ϫ5.3 Ϯ 17.7%, 12.5 Ϯ 17.3%, and 23.9 Ϯ 21.7%, respectively; P Ͻ .05).”
    • Also stated in: § Melatonin suppression · plain
      “Exposure to all light levels (15, 150, and 500 lux) produced significantly greater melatonin suppression in the pre/midpuberty group compared to the late/postpuberty group (P Ͻ .05).”
    Quote in the paperSubstantial claim
  • May combine two claims. 11
  • Classified as probably not a substantial claim. 13

  • May combine two claims.

    Findingown data

    At 30 minutes of morning light exposure, no significant differences were observed between pubertal groups in melatonin suppression, though a trend toward greater suppression at 500 lux in pre/midpubertal compared to late/postpubertal was seen (P=.06).

    “At 30 minutes, no significant differences were observed between pubertal groups; however, a trend toward pre/midpubertal adolescents suppressing more to 500 lux compared to the late/post adolescents (P ϭ .06)was seen.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Pre-bedtime use of light-emitting devices acutely suppresses melatonin production, shifts rhythms later, and causes heightened arousal in adults.

    “Pre-bedtime use of light-emitting devices acutely suppresses melatonin production, shifts rhythms later, and causes heightened arousal in adults (32,33).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [32]

      Not checked in the free run.

    • cites [33]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    A research assistant was present in the room to ensure compliance during light exposure.

    “a research assistant was present in the room to ensure compliance during light exposure.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    Although melatonin suppression is an important marker of light's effects on the circadian timing system, the more relevant factor for mechanisms of entrainment during puberty may be whether maturation affects phase advances and phase delays in responses to light.

    “Thus, although melatonin suppression is an important marker of light's effects on the circadian timing system, the more relevant factor for mechanisms of entrainment during puberty may be whether maturation affects phase advances and phase delays in responses to light.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    All participants were kept on a 9:00 PM to 7:00 AM sleep schedule confirmed by actigraphy and wore eye shades while they slept for a minimum of 10 continuous nights before the in-laboratory study.

    “All participants were kept on a 9:00 PM to 7:00 AM sleep schedule (as confirmed by nondominant wrist actigraphy; Octagonal Basic, Ambulatory Monitoring, Inc) and wore eye shades while they slept for a minimum of 10 continuous nights before the commencement of the in-laboratory study.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    A decrease in the circadian response to light may continue throughout the lifespan because young adults (~18-30 years) show greater phase delay shifts in response to moderate light levels compared to older adults (>65 years).

    “A decrease in the circadian response to light may continue throughout the lifespan because young adults (ϳ18 -30 years) show greater phase delay shifts in response to moderate light levels compared to older adults (Ͼ65 years) (26); physical changes in the lens may account for the reduction of light response in older humans.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [26]

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Reported adverse effects of presleep light-emitting device use by adolescents include reduced total sleep time and delayed sleep onset, and this association is stronger and more persistent for devices held close to the face such as mobile phones and computers.

    “Reported adverse effects of presleep light-emitting device use by adolescents include reduced total sleep time and delayed sleep onset (28,29), an association that is stronger and more persistent for devices held close to the face such as mobile phones and computers (30).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [28]

      Not checked in the free run.

    • cites [29]

      Not checked in the free run.

    • cites [30]

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Given the increased responsiveness of pre/midpubertal adolescents to the delaying effects of light, they may be exposed to an increased risk for the adverse effects of these bedtime behaviors on sleep-wake patterns and circadian timing.

    “Given the increased responsiveness of pre/midpubertal adolescents to the delaying effects of light, they may be exposed to an increased risk for the adverse effects of these bedtime behaviors on sleep-wake patterns and circadian timing.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    Participants were screened for good health, consistent sleep-wake patterns, moderate circadian phase preference, and absence of medication known to affect sleep or circadian rhythms.

    “Participants were screened for good health, consistent sleep-wake patterns (3 hours or less variation in weekday-weekend sleep schedules), moderate circadian phase preference (19), and absence of medication known to affect sleep or circadian rhythms.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [19]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationreasoning

    Greater sensitivity to light in late childhood and early/mid puberty may trigger the adolescent phase delay process, engendering a cascade of later sleep timing and later light exposure with adolescent maturation.

    “Alternatively, greater sensitivity to light in late childhood and early/mid puberty may trigger the adolescent phase delay process, engendering a cascade of later sleep timing and later light exposure with adolescent maturation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The lack of support for the hypothesis that older adolescents would show decreased responsiveness to light in the morning may have resulted from a lack of statistical power.

    “Thus, the lack of support for our hypothesis that older adolescents would show decreased responsiveness to light in the morning may have resulted from a lack of statistical power.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    If mature adolescents are less responsive to morning light, this might help to maintain behaviorally induced delays in circadian rhythms despite early morning light exposure on school days.

    “If mature adolescents are less responsive to morning light, this might help to maintain behaviorally induced delays in circadian rhythms (eg, due to increased evening light exposure opportunity), despite early morning light exposure on school days.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Assignment to either evening or morning light groups was based on participant availability.

    “Assignment to either evening (n ϭ 39; 13 Tanner 1, 4 Tanner 2, 6 Tanner 3, 10 Tanner 4, and 6 Tanner 5) or morning (n ϭ 28; 8 Tanner 1, 6 Tanner 2, 1 Tanner 3, 5 Tanner 4, and 8 Tanner 5) light groups was based on participant availability.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Light administration times were chosen to correspond to times when melatonin was expected to be elevated and during the delay (evening) and advance (morning) portions of the presumed human phase response curve to light.

    “Light administration times were chosen to correspond to times when melatonin was expected to be elevated and during the delay (evening) and advance (morning) portions of the presumed human phase response curve to light (20), given a previous sleep schedule of 9:00 PM to 7:00 AM.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [20]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The salivary melatonin assay had intra-assay coefficients of variation ranging from 2.6 to 10.8% and a functional least detectable value of 0.65 pg/ml.

    “Intra-assay coefficients of variation for this radioimmunoassay kit ranges from 2.6 to 10.8%.The functional least detectable value is 0.65 pg/ml.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    A recent study in humans found greater melatonin suppression to evening light (~580 lux) in children (~7 years) compared to their adult parents (~41 years) and a trend for greater suppression in response to dimmer room light at home in the children (~120-140 lux).

    “Another recent study supports this finding in humans as well, with greater melatonin suppression to evening light (ϳ580 lux) in children (ϳ7 years) compared to their adult parents (ϳ41 years) and a trend for a greater suppression in response to dimmer room light at home in the children (ϳ120 -140 lux) (25).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [25]

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Children who are more sensitive to evening light may manifest a greater phase delay, leading to heightened evening arousal and short mistimed sleep.

    “Children who are more sensitive to evening light may manifest a greater phase delay, leading to heightened evening arousal and short mistimed sleep.”
    Quote in the paperSubstantial claim
17 of 17

  • The paper relies on this without support.

    Melatonin suppression is a valid marker of the circadian system's responsiveness to light.

    “The current study examined melatonin suppression as a measure of the responsiveness of the circadian system to light.”

  • The paper relies on this without support.

    The pre/midpubertal and late/postpubertal groups are comparable on factors other than puberty that affect melatonin suppression.

    “Assignment to either evening (n ϭ 39; 13 Tanner 1, 4 Tanner 2, 6 Tanner 3, 10 Tanner 4, and 6 Tanner 5) or morning (n ϭ 28; 8 Tanner 1, 6 Tanner 2, 1 Tanner 3, 5 Tanner 4, and 8 Tanner 5) light groups was based on participant availability.”

  • The paper relies on this without support.

    The 0.1 lux condition provides an unsuppressed baseline for melatonin.

    “The order of light conditions was approximately 0.1 lux as a baseline condition followed by 15, 150, and 500 lux.”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Light exposure during the night (23:00 h to 24:00 h) suppresses melatonin levels in adolescents, with greater suppression occurring in early adolescents (prepubertal to mid-pubertal adolescents aged 9-14 years) than in late adolescents (aged 11-15 years, in late pubertal to post-pubertal stages).

    “For example, light exposure during the night (23:00 h to 24:00 h) suppresses melatonin levels in adolescents, with greater suppression occurring in early adolescents (prepubertal to mid-pubertal adolescents aged 9–14 years) than in late adolescents (aged 11–15 years, in late pubertal to post-pubertal stages)145.”

    From Rhythms of life: circadian disruption and brain disorders across the lifespan (2019) · cites this paper as [145]

  • Early-morning light exposure (between 03:00 h and 04:00 h) also reduced melatonin, although no differences were found between early and late adolescents.

    “Early-morning light exposure (between 03:00 h and 04:00 h) also reduced melatonin, although no differences were found between early and late adolescents145.”

    From Rhythms of life: circadian disruption and brain disorders across the lifespan (2019) · cites this paper as [145]

  • During adolescence, sensitivity to the phase-shifting effects of light increases.

    “sensitivity to the phase-shifting effects of light increases”

    From Impact of Sleep and Circadian Rhythms on Addiction Vulnerability in Adolescents (2018) · cites this paper as [39]

The citation lists haven’t been fetched yet

References 35 · Cited by 248

Research works printed but not linked: 1

  1. Weinert D, Kompauerova V. Light-induced phase and period re- sponses of circadian activity rhythms in laboratory mice of different age. Zool-Anal Complex Sy. 1998;101:45-52.

Authors
Crowley, S. J., Cain, S. W., Burns, A. C., Acebo, C., & Carskadon, M. A.
Affiliations
Rush University Medical Center (US)
Corresponding author
Carskadon, Mary A.
ORCID
Venue
The Journal of Clinical Endocrinology & Metabolism
Publisher
The Endocrine Society
Published
2015-11
Volume
100
Issue
11
Pages
4067-4073
ISSN
  • 0021-972X (ISSN-L)
  • 1945-7197
DOI
10.1210/jc.2015-2775
PMC
PMC4702443
OpenAlex
W2118739188
Semantic Scholar
a02b2ed856a1cbf669ddda7a6928972204b17e3a
Cited by
248
References
35
Citations by year
2026: 25 · 2025: 23 · 2024: 26 · 2023: 27 · 2022: 36 · 2021: 21 · 2020: 21 · 2019: 20 · 2018: 16 · 2017: 19 · 2016: 10 · 2015: 4
FWCI
9.06
Type
journal article
Language
en
Open access
Locations
  • The Journal of Clinical Endocrinology & Metabolism (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • UniSA Research Outputs Repository (University of South Australia) (acceptedVersion)
  • Adelaide Research & Scholarship (AR&S) (University of Adelaide) (submittedVersion)
Funders
  • National Institutes of Health (5k05mh001358-03, MH01358)
  • National Heart, Lung, and Blood Institute (HL105395, R01HL105395)
  • National Institute of Mental Health (MH52415, MH01358, R01MH052415)
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Health Sciences › Medicine › Reproductive Medicine › Hypothalamic control of reproductive hormones
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
Keywords
puberty, melatonin suppression, light exposure, evening light, sleep timing, adolescents, children, circadian entrainment, salivary melatonin
MeSH terms
Adolescent, Algorithms, Child, Circadian Rhythm, Female, Humans, Light, Male, Melatonin, Photic Stimulation, Puberty, Saliva, Sexual Maturation, Sleep, Circadian Clocks

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