Research Paper Volume 13, Issue 11 pp 14816—14828

Association of changes in self-reported sleep duration with mild cognitive impairment in the elderly: a longitudinal study

Xiyan Wang1, *, , Yan Chen1, *, , Bixuan Yue1, , Sifan Li1, , Qitong Liu1, , Qiaoyu Li1, , Lin Li2,3, , Jiangwei Sun4, ,

  • 1 Department of Public Health, Shenyang Medical College, Liaoning, China
  • 2 School of Medical Sciences, Örebro University, Örebro, Sweden
  • 3 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
  • 4 Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
* Equal contribution

Received: February 22, 2021       Accepted: May 18, 2021       Published: June 6, 2021
How to Cite

Copyright: © 2021 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


As a symptomatic predementia stage with progressive cognitive decline, mild cognitive impairment (MCI) is common with aging. How changes in self-reported sleep duration affect MCI risk in the older adults remains unclear. Participants aged ≥ 65 years and enrolled at least two waves in the Chinese Longitudinal Healthy Longevity Survey were included in present longitudinal study. Changes in sleep duration were calculated as the difference between two waves and categorized into five groups: decreased >2 h, decreased 0-2h, stable, increased 0-2 h, and increased >2 h. MCI was measured by the Chinese version of the Mini-Mental State Examination. Generalized estimating equation model and restricted cubic spline function was applied to investigate the association. Among 9,005 participants (mean age, 81.19 years; 4,391 male), 2,877 developed MCI. Comparing with individuals with stable sleep duration, MCI risk [odds ratio (95% confidence intervals)] was: 1.15 (0.99-1.34) for decreased >2 h, 0.99 (0.87-1.13) for decreased 0-2h, 1.09 (0.95-1.24) for increased 0-2 h, and 1.57 (1.36-1.81) for increased >2 h, respectively. Similar patterns were observed among subgroup analyses by sex, age, and sleep quality at baseline. For participants with long sleep duration at baseline (>8h), further increased >2 h was associated with higher MCI risk [2.23 (1.55-3.21)]. Either in the whole or subgroup population, a U-shaped association was observed (Pnon-linearity<0.05). In conclusion, changes in self-reported sleep duration were associated with MCI risk in a U-shaped pattern. Strategies that shifting sleep duration into normal range and keeping it stable are essential to prevent MCI in clinical practice.


ADL: activities in daily living; CI: confident interval; CLHLS: the Chinese Longitudinal Healthy Longevity Survey; CRP: C-reactive protein; IL-6: interleukin-6; IQR: interquartile range; MCI: mild cognitive impairment; MMSE: the Mini-Mental State Examination; OR: odds ratio; SD: standard deviation.