Earlier chronotype in midlife as a predictor of accelerated brain aging: a population-based longitudinal cohort study

Hyeon Jin Kim, Regina E.Y. Kim, Soriul Kim, Seung Ku Lee, Hyang Woon Lee, Chol Shin

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Study Objectives: Evidence suggests that sleep-wake cycle disruption could be an early manifestation of neurodegeneration and might even be a risk factor for developing diseases in healthy adults. We investigated the impact of circadian phase change on structural and functional brain deterioration in a late-adulthood population. Methods: We analyzed the data of 1874 participants (mean age 58.6 ± 6.3 years, 50.3% female) from the Korean Genome and Epidemiology Study, who were identified as cognitively unimpaired. The mid-sleep time on free days corrected for sleep debt on workdays (MSFsc) at baseline was adopted as an indicator of the chronotype and used to categorize the participants into three groups. The relationships between the chronotype and longitudinal changes in the gray matter volume (GMV) and cognitive function were investigated (mean interval: 4.2 ± 0.5 years). Results: The mean MSFsc of the participants was 2:45 am. The earlier MSFsc was linearly associated with smaller right entorhinal GMV (β [SE] = 0.02 [0.01]; p =. 001) and lower visual memory function test scores at baseline. Longitudinally, the earlier MSFsc at baseline was only significantly associated with more rapid atrophy in the temporal lobe (β [SE] = 0.18 [0.07]; p =. 018) and not with other brain lobes or subregions. Moreover, the earlier MSFsc was associated with more deteriorated verbal learning and visual memory function test scores. Conclusions: An earlier chronotype in midlife, measured using a questionnaire, can be a valuable indicator for individuals who should be closely monitored for the development of neurodegenerative disorders.

Original languageEnglish
Article numberzsad108
Issue number6
StatePublished - 1 Jun 2023

Bibliographical note

Funding Information:
This study was supported by grants from the Korean Centers for Disease Control and Prevention (2011-E71004-00, 2012-E71005-00, 2013-E71005-00, 2014-E71003-00, 2015-P71001-00, 2016-E71003-00, 2017-E71001-00, and 2018-E7101-00 to C. Shin), the Korean Ministry of Health & Welfare through Korea Health Technology R & D Project of Korea Health Industry Development Institute (HI19C1065 to H. J. Kim, and HI20C0469 to S. Kim), the Korea University Ansan Hospital (O2207181 and O2206301 to H. J. Kim), the National Research Foundation of Korea(NRF) funded by the Ministry of Science, Information and Communication Technologies(MSIT) and Ministry of Education & Future Planning (NRF-2019M3C1B8090803 and 2020R1A2C2013216 to H. W. Lee, NRF-2020R1I1A1A01071011 and NRF-2022R1I1A1A01065700 to S. Kim, and NRF-2020R1I1A1A01073927 to R. E. Kim), and the Institute of Information & communications Technology Planning & Evaluation(IITP) funded by the MSIT (RS-2022-00155966 to H. W. Lee).

Publisher Copyright:
© 2023 The Author(s). Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved.


  • aging
  • chronotype
  • cognitive decline
  • cohort study
  • dementia
  • entorhinal cortex
  • memory impairment
  • neurodegenerative disorders
  • temporal lobe


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