Evidence map›Paper›PMID 25891543›Full record

ArticleSleep medicine2015

Caffeine does not entrain the circadian clock but improves daytime alertness in blind patients with non-24-hour rhythms.

Melissa A St Hilaire, Steven W Lockley

Open access · hybridAbstract readControlled Clinical Trial
PubMed Full text at PMC Publisher
In one paragraph

Article in Sleep medicine, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.

0numbers the graph read from it
0cells of the map it votes in
15citing papers in PubMed
1.3field-weighted citation impact, top 21% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

15 citing papers in PubMed, 31 citations in OpenAlex.

  1. Trial
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  9. Review
  10. Review
  11. How Psychoactive Drugs and the Circadian Clock Are Enlightening One Another.Advances in experimental medicine and biology · 2021
    Article
  12. Review
  13. Article
  14. Nutrition and the circadian system.The British journal of nutrition · 2016
    Review
  15. A Pre-Screening Questionnaire to Predict Non-24-Hour Sleep-Wake Rhythm Disorder (N24HSWD) among the Blind.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2016
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 2 institutions in 2 countries.

Melissa A St HilaireDivision of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA.
Steven W LockleyDivision of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA, USA; Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK. Electronic address: slockley@hms.harvard.edu.
Circadian (United States) · USHarvard University · US

Funding

TRAINING IN SLEEP, CIRCADIAN &RESPIRATORY NEUROBIOLOGYT32HL007901 · NHLBI · BRIGHAM AND WOMEN'S HOSPITAL · PI Charles A Czeisler · 1998 to 2026
$18.5M
NHLBI NIH HHS T32 HL007901NHLBI NIH HHS T32 HL079010Wellcome Trust 060018/B/99/Z
6 · The paper itself

Abstract

OBJECTIVE/

backgroundTotally blind individuals are highly likely to suffer from Non-24-Hour Sleep-Wake Disorder due to a failure of light to reset the circadian pacemaker in the suprachiasmatic nuclei. In this outpatient case series, we investigated whether daily caffeine administration could entrain the circadian pacemaker in non-entrained blind patients to alleviate symptoms of non-24-hour sleep-wake disorder. PATIENTS/

methodsThree totally blind males (63.0 ± 7.5 years old) were studied at home over ~4 months. Urinary 6-sulphatoxymelatonin (aMT6s) rhythms were measured for 48 h every 1-2 weeks. Participants completed daily sleep-wake logs, and rated their alertness and mood using nine-point scales every ~2-4 h while awake on urine sampling days. Caffeine capsules (150 mg per os) were self-administered daily at 10 a.m. for approximately one circadian beat cycle based on each participant's endogenous circadian period τ and compared to placebo (n = 2) or no treatment (n = 1) in a single-masked manner.

resultsNon-24-h aMT6s rhythms were confirmed in all three participants (τ range = 24.32-24.57 h). Daily administration of 150 mg caffeine did not entrain the circadian clock. Caffeine treatment significantly improved daytime alertness at adverse circadian phases (p <0.0001) but did not decrease the occurrence of daytime naps compared with placebo.

conclusionsAlthough caffeine was able to improve daytime alertness acutely and may therefore provide temporary symptomatic relief, the inability of caffeine to correct the underlying circadian disorder means that an entraining agent is required to treat Non-24-Hour Sleep-Wake Disorder in the blind appropriately.

Indexed as

AffectAgedArousalBlindnessCaffeineCircadian ClocksHumansMaleMelatoninMiddle AgedPolysomnographySleep Disorders, Circadian Rhythm6-sulfatoxymelatoninCaffeineMelatoninAlertnessBlindnessCaffeineCircadianEntrainmentNon-24-hour sleep–wake disorder

Identifiers

PMID25891543
PMCPMC4465963
OpenAlexW2010106590

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.