Sleep duration, cognitive decline, and dementia risk in older women

Jiu-Chiuan Chen; Mark A Espeland; Robert L Brunner; Laura C Lovato; Robert B Wallace; Xiaoyan Leng; Lawrence S Phillips; Jennifer G Robinson; Jane M Kotchen; Karen C Johnson; JoAnn E Manson; Marcia L Stefanick; Gloria E Sarto; W Jerry Mysiw

doi:10.1016/j.jalz.2015.03.004

Sleep duration, cognitive decline, and dementia risk in older women

Alzheimers Dement. 2016 Jan;12(1):21-33. doi: 10.1016/j.jalz.2015.03.004. Epub 2015 Jun 15.

Authors

Affiliations

¹ Department of Preventive Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA. Electronic address: jcchen@usc.edu.
² Division of Public Health Sciences, Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
³ Department of Family and Community Medicine, University of Nevada School of Medicine, Reno, NV, USA.
⁴ Departments of Epidemiology & Medicine, University of Iowa, Iowa City, IA, USA.
⁵ Atlanta VA Medical Center and Division of Endocrinology, Emory University School of Medicine, Atlanta, GA, USA.
⁶ Department of Population Health, Medical College of Wisconsin, Milwaukee, WI, USA.
⁷ Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
⁸ Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
⁹ Department of Medicine, Stanford University, Stanford, CA, USA.
¹⁰ University of Wisconsin Center for Women's Health Research, Madison, WI, USA.
¹¹ Department of Physical Medicine and Rehabilitation, Ohio State University, Columbus, OH, USA.

Abstract

Introduction: Consistent evidence linking habitual sleep duration with risks of mild cognitive impairment (MCI) and dementia is lacking.

Methods: We conducted a prospective study on 7444 community-dwelling women (aged 65-80 y) with self-reported sleep duration, within the Women's Health Initiative Memory Study in 1995-2008. Incident MCI/dementia cases were ascertained by validated protocols. Cox models were used to adjust for multiple sociodemographic and lifestyle factors, depression, cardiovascular disease (CVD), and other clinical characteristics.

Results: We found a statistically significant (P = .03) V-shaped association with a higher MCI/dementia risk in women with either short (≤6 hours/night) or long (≥8 hours/night) sleep duration (vs. 7 hours/night). The multicovariate-adjusted hazard for MCI/dementia was increased by 36% in short sleepers irrespective of CVD, and by 35% in long sleepers without CVD. A similar V-shaped association was found with cognitive decline.

Discussion: In older women, habitual sleep duration predicts the future risk for cognitive impairments including dementia, independent of vascular risk factors.

Keywords: Cognition; Cognitive decline; Cohort studies; Dementia; Elderly; Longitudinal analysis; Mild cognitive impairment; Sleep duration.

Publication types

Randomized Controlled Trial
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Aged
Aged, 80 and over
Cognitive Dysfunction / etiology*
Dementia / etiology*
Disorders of Excessive Somnolence / complications*
Female
Humans
Proportional Hazards Models
Prospective Studies
Risk Factors
Sleep Initiation and Maintenance Disorders / complications*
Sleep*

Abstract

Publication types

MeSH terms

Grants and funding