Research Paper Volume 12, Issue 1 pp 309—317

Changes in sleep duration and 3-year risk of mild cognitive impairment in Chinese older adults

Qi Zhu1, , Hui Fan1, , Xiaoning Zhang2, , Chao Ji3, , Yang Xia3, ,

  • 1 Department of Preventive Medicine, North Sichuan Medical College, Nanchong, China
  • 2 Institute of Basic Medicine, Shandong First Medical University and Shandong Academy of Medical Sciences, Shandong, China
  • 3 Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China

Received: August 20, 2019       Accepted: December 5, 2019       Published: January 3, 2020
How to Cite

Copyright: © 2020 Zhu 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.


Objective: This study aimed to determine whether changes in sleep duration are associated with a higher risk of mild cognitive impairment (MCI) in older adults.

Results: By the 3-year follow-up, 592 participants developed MCI. Compared with the individuals who had an unchanged sleep duration, the odds ratio (95% confidence interval) for MCI was 1.44 (1.08-1.91) for those whose sleep duration increased by ≥2 h after multivariate adjustments. Moreover, changing from a long to moderate, but not short, sleep duration was negatively associated with the incidence of MCI (odds ratio: 0.65; 95% confidence interval, 0.45-0.93).

Conclusions: These findings suggest that increased sleep duration is associated with a higher risk of MCI in the elderly. Furthermore, a moderate duration of sleep (6-9 h) could serve as a possible strategy for prevention of MCI.

Methods: This longitudinal study was conducted with a nationally representative sample of 5419 older Chinese adults (≥65 years) from the 2008 and 2011 waves of the Chinese Longitudinal Healthy Longevity Survey. Sleep duration was assessed by a self-administered questionnaire. MCI was defined according to the Mini-Mental State Examination. An adjusted logistic regression model was used to explore the associations between changes in sleep duration and MCI.


MCI: mild cognitive impairment; CLHLS: Chinese Longitudinal Healthy Longevity Survey; ADL: activities of daily living; BMI: body mass index; MMSE: Mini-Mental State Examination; OR: odds ratio; CI: confidence interval; ANOVA: analysis of variance.