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Cited by 296Sleep and Work-Related FatigueHormonal and reproductive studiesCircadian rhythm and melatonin

Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men

Open access
Leproult, Rachel·2011·JAMA
DOI 10.1001/jama.2011.710PMC PMC4445839
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Abstract

To the Editor: Chronic sleep curtailment is endemic in modern societies. The majority of the daily testosterone release in men occurs during sleep.1 Sleep fragmentation and obstructive sleep apnea are associated with reduced testosterone levels.2 In older men, morning testosterone levels are partly predicted by total sleep time.3 Testosterone is critical in male sexual behavior and reproduction, but also has important beneficial effects on muscle mass and strength, adiposity, bone density, and vigor and well-being.4 We investigated the effect of 1 week of sleep restriction on testosterone levels in young healthy men.

AI snapshot

Written from the paper’s full text.

TL;DR

In 10 young healthy men, 1 week of sleep restriction to 5 hours per night reduced daytime testosterone levels by 10% to 15% compared with a rested condition. The testosterone decline was associated with lower vigor scores but not with increased cortisol.

Key findings

  • Total sleep time decreased from 8 hours 55 minutes (35 min) to 4 hours 48 minutes (6 min) with sleep restriction (P = .002); participants lost 2 hours 45 minutes (29 min) of stage-2 sleep and 1 hour 3 minutes (18 min) of REM sleep, and gained 9 minutes (8 min) of stages 3 + 4 sleep (P = .01).
  • During waking hours common to both conditions (8 AM–10 PM), testosterone levels were lower after sleep restriction than in the rested condition: 16.5 (2.8) nmol/L vs 18.4 (3.8) nmol/L (P = .049); the effect was especially apparent between 2 PM and 10 PM: 15.5 (3.1) nmol/L vs 17.9 (4.0) nmol/L (P = .02).
  • Daytime cortisol profiles were similar under both conditions. Mean (SD) vigor scores decreased from 28 (5) after the first night to 19 (7) after the seventh night of restriction (P = .002).
  • The authors report that daytime testosterone levels decreased by 10% to 15%, compared with a normal aging decrease of 1% to 2% per year.

Methods

  • Ten men passed all screening tests and completed the study; mean (SD) age was 24.3 (4.3) years and mean (SD) BMI was 23.5 (2.4). The protocol was approved by the University of Chicago institutional review board, and the study was performed between January 2003 and September 2009.
  • After 1 week of 8-hour bedtimes at home, participants spent 11 days in the laboratory: 3 nights of 10-hour bedtimes (rested condition) followed by 8 nights of 5-hour bedtimes (sleep restriction). Sleep was recorded and visually scored; blood was sampled every 15 to 30 minutes for 24 hours after the second 10-hour night and after the seventh 5-hour night, and samples were assayed for total testosterone and cortisol.
  • Participants completed visual analog scales for global vigor and global affect at 2-hour intervals each day. Comparisons between conditions used 2-sided nonparametric Wilcoxon tests with a significance level of .05.

Limitations

  • The paper states that this was a small convenience sample of young healthy men and that additional investigations are needed to determine whether sleep duration should be integrated into the evaluation of androgen deficiency.
  • The text makes evident that only 10 of 28 consented persons completed the study, and the design used a within-subject comparison of rested versus restricted conditions rather than a separate control group.
  • The text makes evident that findings may not generalize beyond young healthy men; no other populations were studied.

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

Integrity signals

Registry

Crossref · 10.1001/jama.2011.710

Cites

6 of 6 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

1 of 6 cited sources checked · 0 supported · 0 flagged · accuracy not yet measured

  • Findingown data

    During waking hours common to both conditions (8 AM-10 PM), testosterone levels were lower after sleep restriction than in the rested condition (16.5 [2.8] nmol/L vs 18.4 [3.8] nmol/L; P = .049).

    “During waking hours common to both conditions (8 AM-10 PM), testosterone levels were lower after sleep restriction than in the rested condition (16.5 [2.8] nmol/L vs 18.4 [3.8] nmol/L; P = .049).”
    Quote in the paperSubstantial claim
  • Findingown data

    The effect of restricted sleep on testosterone was especially apparent between 2 PM and 10 PM (15.5 [3.1] nmol/L vs 17.9 [4.0] nmol/L; P = .02).

    “The effect of restricted sleep was especially apparent between 2 PM and 10 PM (15.5 [3.1] nmol/L vs 17.9 [4.0] nmol/L; P = .02).”
    Quote in the paperNot a substantial claim
  • Findingown data

    Daytime testosterone levels were decreased by 10% to 15% in this small convenience sample of young healthy men who underwent 1 week of sleep restriction to 5 hours per night.

    “Daytime testosterone levels were decreased by 10% to 15% in this small convenience sample of young healthy men who underwent 1 week of sleep restriction to 5 hours per night”
    Quote in the paperSubstantial claim
  • Findingown data

    During each restricted night, participants lost 2 hours 45 minutes of stage-2 sleep.

    “Relative to the rested condition, during each restricted night, participants lost a total (SD) of 2 hours 45 minutes (29 min) of stage-2 sleep (P = .002)”
    Quote in the paperNot a substantial claim
  • Findingown data

    Total sleep time decreased from 8 hours 55 minutes to 4 hours 48 minutes with sleep restriction.

    “Total (SD) sleep time decreased from 8 hours 55 minutes (35 min) to 4 hours 48 minutes (6 min) with sleep restriction (P = .002).”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 8
  • May combine two claims. 3

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

    Premisecitation

    Normal aging is associated with a decrease of testosterone levels by 1% to 2% per year.

    “By comparison, normal aging is associated with a decrease of testosterone levels by 1% to 2% per year.6”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [6] Harman SM Metter EJ Tobin JD Pearson J Blackman MR Baltimore Longitudinal Study of Aging. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. J Clin Endocrinol Metab 2001 86 2 724 731 PubMed | Link to Article 11158037 source

      The Discussion reports that total testosterone and the free testosterone index declined with age in 890 generally healthy men, but gives the annual decline in absolute units, not as 1%–2%. Its reported total-testosterone decline of 0.110 nmol/L per year is about 0.6% of the 17.6 nmol/L mean for younger men given in Statistical analysis. The specific 1%–2% annual rate is therefore not established for testosterone levels generally. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    This testosterone decline was associated with lower vigor scores but not with increased levels of cortisol.

    “This testosterone decline was associated with lower vigor scores but not with increased levels of cortisol”
    Quote in the paperSubstantial claim

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

    Findingown data

    Daytime cortisol profiles were similar under both conditions.

    “Daytime cortisol profiles were similar under both conditions (Figure).”
    Quote in the paperNot a substantial claim

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

    Findingown data

    During each restricted night, participants gained 9 minutes of sleep in stages 3 + 4.

    “and gained 9 minutes (8 min) of sleep in stages 3 + 4 (P = .01).”
    Quote in the paperNot a substantial claim

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

    Premisecitation
    § Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy MenFREE

    In older men, morning testosterone levels are partly predicted by total sleep time.

    “In older men, morning testosterone levels are partly predicted by total sleep time.3”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [3] Penev PD Association between sleep and morning testosterone levels in older men. Sleep 2007 30 4 427 432 PubMed 17520786 source

  • May combine two claims.

    Premisecitation
    § Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy MenFREE

    Sleep fragmentation and obstructive sleep apnea are associated with reduced testosterone levels.

    “Sleep fragmentation and obstructive sleep apnea are associated with reduced testosterone levels.2”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [2] Andersen ML Tufik S The effects of testosterone on sleep and sleep-disordered breathing in men: its bidirectional interaction with erectile function. Sleep Med Rev 2008 12 5 365 379 PubMed | Link to Article 18519168 source

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

    Premisecitation
    § Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy MenFREE

    Testosterone has important beneficial effects on muscle mass and strength, adiposity, bone density, and vigor and well-being.

    “Testosterone is critical in male sexual behavior and reproduction, but also has important beneficial effects on muscle mass and strength, adiposity, bone density, and vigor and well-being.4”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Bremner WJ Testosterone deficiency and replacement in older men. N Engl J Med 2010 363 2 189 191 PubMed | Link to Article 20647215 source

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

    Study design and conductnone given

    The sample size was estimated using data from previous work on the hormonal impact of sleep restriction.

    “The sample size was estimated using data from previous work on the hormonal impact of sleep restriction.”
    Quote in the paperNot a substantial claim

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

    Study design and conductown data

    Ten men passed all screening tests and completed the study.

    “Ten men passed all screening tests and completed the study, which was performed between January 2003 and September 2009.”
    Quote in the paperNot a substantial claim

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

    Premisecitation
    § Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy MenFREE

    Testosterone is critical in male sexual behavior and reproduction.

    “Testosterone is critical in male sexual behavior and reproduction, but also has important beneficial effects on muscle mass and strength, adiposity, bone density, and vigor and well-being.4”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Bremner WJ Testosterone deficiency and replacement in older men. N Engl J Med 2010 363 2 189 191 PubMed | Link to Article 20647215 source
10 of 10

  • The paper relies on this without support.

    Chronic sleep curtailment is endemic in modern societies.

    “Chronic sleep curtailment is endemic in modern societies.”

  • The paper relies on this without support.

    Sleep restriction to 5 hours per night is experienced by at least 15% of the US working population.

    “a condition experienced by at least 15% of the US working population”

  • The paper relies on this without support.

    Cortisol is a stress-responsive hormone that can inhibit gonadal function.

    “a stress-responsive hormone that can inhibit gonadal function”
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?

  • Sleep loss and lower sleep duration are associated with lower morning, afternoon, and 24-h testosterone.

    “When epidemiological and interventional studies are considered collectively, sleep loss and lower sleep duration are associated with lower morning, afternoon and 24-h testosterone; as well as higher afternoon, but not morning or 24-h cortisol.”

    From Sleep, testosterone and cortisol balance, and ageing men (2022) · cites this paper as [41]

    The Results (page unavailable) report lower testosterone during waking hours after sleep restriction, particularly from 2 PM to 10 PM. The paper also notes an association between sleep time and morning testosterone in older men, but it does not report a lower 24-hour testosterone level; collecting samples over 24 hours does not establish that result. (LLM, conf=0.87)

    Experimental — accuracy not yet measured

  • All in-laboratory studies when collectively examined show that sleep restriction decreases testosterone.

    “All studies when collectively examined show that sleep restriction decreases testosterone.”

    From Sleep, testosterone and cortisol balance, and ageing men (2022) · cites this paper as [41]

    The Results report lower daytime testosterone after one week of laboratory sleep restriction in 10 healthy young men. This supports the direction of the effect in this study, but the paper does not collectively examine all in-laboratory studies or establish that all studies show a decrease. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • That study found a decrease in afternoon and evening plasma testosterone levels after eight nights of sleep restriction to five hours per night.

    “It found a decrease in afternoon and evening (14:00–22:00) plasma testosterone levels after eight nights of sleep restriction to five hours per night.”

    From Impact of Five Nights of Sleep Restriction on Glucose Metabolism, Leptin and Testosterone in Young Adult Men (2012) · cites this paper as [45]

    The Results report lower testosterone levels between 2 PM and 10 PM during sleep restriction. The Methods say the protocol included eight nights of five-hour bedtimes, but blood sampling began after the seventh restricted night; the reported afternoon and evening decrease was therefore not measured after eight completed nights. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • Only one experimental laboratory based study has investigated the impact of partial sleep restriction on testosterone.

    “While observational studies have identified a relationship between total sleep deprivation and reduced testosterone [43], [44], only one experimental laboratory based study has investigated the impact of partial sleep restriction on testosterone [45].”

    From Impact of Five Nights of Sleep Restriction on Glucose Metabolism, Leptin and Testosterone in Young Adult Men (2012) · cites this paper as [45]

    The Methods describe a laboratory experiment comparing rested nights with eight nights of restricted sleep and measuring testosterone. This confirms that the cited paper is such a study, but the paper does not establish that it was the only one. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Only published data found testosterone decreased significantly after 8 nights of 5 hours time in bed.

    “the only published data to date on the relationship between sleep restriction and testosterone found that levels decreased significantly after 8 nights of 5 hours time in bed [45].”

    From Impact of Five Nights of Sleep Restriction on Glucose Metabolism, Leptin and Testosterone in Young Adult Men (2012) · cites this paper as [45]

    The Methods describe an eight-night protocol with five hours in bed per night, and the Results report significantly lower testosterone during waking hours after restriction (P = .049). However, blood sampling began after the seventh restricted night, not after all eight nights. The paper also does not establish that these were the only published data to date. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

Cites

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Related

Authors
Leproult, R.
Affiliations
University of Chicago (US)
Corresponding author
Leproult, Rachel
ORCID
Leproult, Rachel
Venue
JAMA
Publisher
American Medical Association (AMA)
Published
2011-06-01
Volume
305
Issue
21
Pages
2173
ISSN
  • 0002-9955 (ISSN-L)
  • 0098-7484
DOI
10.1001/jama.2011.710
PMC
PMC4445839
OpenAlex
W2041222578
Semantic Scholar
e384bbd6f4574958ec1732087a2f11f03de4802a
Cited by
296
References
6
Citations by year
2026: 27 · 2025: 34 · 2024: 18 · 2023: 16 · 2022: 31 · 2021: 25 · 2020: 22 · 2019: 25 · 2018: 21 · 2017: 14 · 2016: 12 · 2015: 12 · 2014: 11 · 2013: 14 · 2012: 10
FWCI
14.52
Type
journal article
Language
en
Open access
Locations
  • JAMA (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Dépôt institutionnel de l'Université libre de Bruxelles (Université Libre de Bruxelles) (submittedVersion)
Funders
  • National Heart, Lung, and Blood Institute (R01HL072694, 5R01HL72694-5)
  • National Institute of Diabetes and Digestive and Kidney Diseases (P60DK020595)
  • National Center for Research Resources (M01RR000055, MO1 RR-00055)
Topics
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
Keywords
sleep restriction, testosterone, sleep deprivation, androgen levels, young men, healthy men
MeSH terms
Adult, Fatigue, Humans, Hydrocortisone, Male, Sleep Deprivation, Testosterone, Young Adult

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