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Cited by 607

The DOI matches its Crossref record; 72 of the 72 references it cites were found in a registry or an index.

Sex difference in the near-24-hour intrinsic period of the human circadian timing system

Open access
Duffy, Jeanne F., Cain, Sean W., Chang, Anne-Marie, Phillips, Andrew J. K., Münch, Mirjam Y., Gronfier, Claude, Wyatt, James K., Dijk, Derk-Jan, Wright, Kenneth P., Czeisler, Charles A.·2011·Proceedings of the National Academy of Sciences
DOI 10.1073/pnas.1010666108
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Abstract

The circadian rhythms of melatonin and body temperature are set to an earlier hour in women than in men, even when the women and men maintain nearly identical and consistent bedtimes and wake times. Moreover, women tend to wake up earlier than men and exhibit a greater preference for morning activities than men. Although the neurobiological mechanism underlying this sex difference in circadian alignment is unknown, multiple studies in nonhuman animals have demonstrated a sex difference in circadian period that could account for such a difference in circadian alignment between women and men. Whether a sex difference in intrinsic circadian period in humans underlies the difference in circadian alignment between men and women is unknown. We analyzed precise estimates of intrinsic circadian period collected from 157 individuals (52 women, 105 men; aged 18–74 y) studied in a month-long inpatient protocol designed to minimize confounding influences on circadian period estimation. Overall, the average intrinsic period of the melatonin and temperature rhythms in this population was very close to 24 h [24.15 ± 0.2 h (24 h 9 min ± 12 min)]. We further found that the intrinsic circadian period was significantly shorter in women [24.09 ± 0.2 h (24 h 5 min ± 12 min)] than in men [24.19 ± 0.2 h (24 h 11 min ± 12 min); P < 0.01] and that a significantly greater proportion of women have intrinsic circadian periods shorter than 24.0 h (35% vs. 14%; P < 0.01). The shorter average intrinsic circadian period observed in women may have implications for understanding sex differences in habitual sleep duration and insomnia prevalence.

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Metadata

Authors
Duffy, J. F., Cain, S. W., Chang, A.-M., Phillips, A. J. K., Münch, M. Y., Gronfier, C., Wyatt, J. K., Dijk, D.-J., Wright, K. P., & Czeisler, C. A.
Venue
Proceedings of the National Academy of Sciences
Publisher
Proceedings of the National Academy of Sciences
Published
2011-05-02
Volume
108
Issue
supplement_3
Pages
15602-15608
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
DOI
10.1073/pnas.1010666108
OpenAlex
W2034585240
Cited by
607
References
72
FWCI
11.18
Type
journal article
Language
en
Open access
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CoChat. (2026). Citation check: Sex difference in the near-24-hour intrinsic period of the human circadian timing system. https://app.cochat.ai/papers/10.1073/pnas.1010666108
The paper
Duffy, J. F., Cain, S. W., Chang, A.-M., Phillips, A. J. K., Münch, M. Y., Gronfier, C., Wyatt, J. K., Dijk, D.-J., Wright, K. P., & Czeisler, C. A. (2011). Sex difference in the near-24-hour intrinsic period of the human circadian timing system. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1010666108

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Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.