Sleep characteristics and cognitive impairment in the general population: The HypnoLaus study

José Haba-Rubio; Helena Marti-Soler; Nadia Tobback; Daniela Andries; Pedro Marques-Vidal; Gérard Waeber; Peter Vollenweider; Armin von Gunten; Martin Preisig; Enrique Castelao; Mehdi Tafti; Raphaël Heinzer; Julius Popp

doi:10.1212/WNL.0000000000003557

Sleep characteristics and cognitive impairment in the general population: The HypnoLaus study

Neurology. 2017 Jan 31;88(5):463-469. doi: 10.1212/WNL.0000000000003557. Epub 2016 Dec 30.

Affiliations

¹ From the Center for Investigation and Research in Sleep (J.H.-R., N.T., D.A., M.T., R.H.), Institute of Social and Preventive Medicine (H.M.-S), Department of Medicine, Service of Internal Medicine (P.M.-V., G.W., P.V.), Department of Psychiatry, Service of Old-Age Psychiatry (A.v.G., J.P.), Department of Psychiatry (M.P., E.C.), Center for Integrative Genomics (M.T.), Department of Clinical Neuroscience, and Leenaards Memory Center (J.P.), Lausanne University Hospital (CHUV) and Lausanne University, Lausanne, Switzerland. jose.haba-rubio@chuv.ch julius.popp@chuv.ch.
² From the Center for Investigation and Research in Sleep (J.H.-R., N.T., D.A., M.T., R.H.), Institute of Social and Preventive Medicine (H.M.-S), Department of Medicine, Service of Internal Medicine (P.M.-V., G.W., P.V.), Department of Psychiatry, Service of Old-Age Psychiatry (A.v.G., J.P.), Department of Psychiatry (M.P., E.C.), Center for Integrative Genomics (M.T.), Department of Clinical Neuroscience, and Leenaards Memory Center (J.P.), Lausanne University Hospital (CHUV) and Lausanne University, Lausanne, Switzerland.

PMID: 28039311
DOI: 10.1212/WNL.0000000000003557

Abstract

Objective: To assess the association between sleep structure and cognitive impairment in the general population.

Methods: Data stemmed from 580 participants aged >65 years of the population-based CoLaus/PsyCoLaus study (Lausanne, Switzerland) who underwent complete sleep evaluation (HypnoLaus). Evaluations included demographic characteristics, personal and treatment history, sleep complaints and habits (using validated questionnaires), and a complete polysomnography at home. Cognitive function was evaluated using a comprehensive neuropsychological test battery and a questionnaire on the participant's everyday activities. Participants with cognitive impairment (global Clinical Dementia Rating [CDR] scale score > 0) were compared with participants with no cognitive impairment (global CDR score = 0).

Results: The 291 participants with a CDR score > 0 (72.5 ± 4.6 years), compared to the 289 controls with CDR = 0 (72.1 ± 4.6 years), had significantly more light (stage N1) and less deep (stage N3) and REM sleep, as well as lower sleep efficiency, higher intrasleep wake, and higher sleepiness scores (all p < 0.05). Sleep-disordered breathing was more severe in participants with cognitive impairment with an apnea/hypopnea index (AHI) of 18.0 (7.8-35.5)/h (p50 [p25-p75]) (vs 12.9 [7.2-24.5]/h, p < 0.001), and higher oxygen desaturation index (ODI). In the multivariate analysis after adjustments for confounding variables, the AHI and the ODI ≥4% and ≥6% were independently associated with cognitive impairment.

Conclusions: Participants aged >65 years with cognitive impairment have higher sleepiness scores and a more disrupted sleep. This seems to be related to the occurrence of sleep-disordered breathing and the associated intermittent hypoxia.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Cognitive Dysfunction / complications
Cognitive Dysfunction / physiopathology*
Follow-Up Studies
Humans
Mental Status Schedule
Multivariate Analysis
Neuropsychological Tests
Polysomnography
Severity of Illness Index
Sleep Wake Disorders / complications
Sleep Wake Disorders / physiopathology
Sleep Wake Disorders / psychology
Sleep* / physiology
Surveys and Questionnaires
Switzerland