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Kivimäki M, Singh-Manoux A, Batty GD, et al. Association of Alcohol-Induced Loss of Consciousness and Overall Alcohol Consumption With Risk for Dementia. JAMA Netw Open. 2020;3(9):e2016084. doi:10.1001/jamanetworkopen.2020.16084

Association of alcohol-induced loss of consciousness and overall alcohol consumption with risk for dementia

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Author: Kivimäki, Mika1,2; Singh-Manoux, Archana1,3; Batty, G. David1,4;
Organizations: 1Department of Epidemiology and Public Health, University College London, London, United Kingdom
2Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
3Epidemiology of Ageing and Neurodegenerative Diseases, INSERM U1153, Université de Paris, Paris, France
4Oregon State University School of Biological and Population Health Sciences, Corvallis, Oregon
5Division of Psychiatry, University College London, London, United Kingdom
6Camden and Islington NHS Foundation Trust, London, United Kingdom
7Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
8Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
9Department of Public Health, University of Turku, Turku, Finland
10Centre for Population Health Research, Turku University Hospital, University of Turku, Turku, Finland
11Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
12University of Skövde School of Health and Education, Skövde, Sweden
13Finnish Institute of Occupational Health, Helsinki, Finland
14Population-Based Epidemiological Cohorts Unit, INSERM UMS 011, Villejuif, France
15Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
16Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden
17Department of Medical Sciences, Uppsala University, Uppsala, Sweden
18Department of Health Sciences, Mid Sweden University, Sundsvall, Sweden
19Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, United Kingdom
20Department of Medicine, Helsinki University Hospital, Helsinki, Finland
21Center for Life Course Health Research, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.2 MB)
Persistent link:
Language: English
Published: American Medical Association, 2020
Publish Date: 2020-12-02


Importance: Evidence on alcohol consumption as a risk factor for dementia usually relates to overall consumption. The role of alcohol-induced loss of consciousness is uncertain.

Objective: To examine the risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers.

Design, Setting, and Participants: Seven cohort studies from the UK, France, Sweden, and Finland (IPD-Work consortium) including 131 415 participants were examined. At baseline (1986–2012), participants were aged 18 to 77 years, reported alcohol consumption, and were free of diagnosed dementia. Dementia was examined during a mean follow-up of 14.4 years (range, 12.3-30.1). Data analysis was conducted from November 17, 2019, to May 23, 2020.

Exposures: Self-reported overall consumption and loss of consciousness due to alcohol consumption were assessed at baseline. Two thresholds were used to define heavy overall consumption: greater than 14 units (U) (UK definition) and greater than 21 U (US definition) per week.

Main Outcomes and Measures: Dementia and alcohol-related disorders to 2016 were ascertained from linked electronic health records.

Results: Of the 131 415 participants (mean [SD] age, 43.0 [10.4] years; 80 344 [61.1%] women), 1081 individuals (0.8%) developed dementia. After adjustment for potential confounders, the hazard ratio (HR) was 1.16 (95% CI, 0.98-1.37) for consuming greater than 14 vs 1 to 14 U of alcohol per week and 1.22 (95% CI, 1.01-1.48) for greater than 21 vs 1 to 21 U/wk. Of the 96 591 participants with data on loss of consciousness, 10 004 individuals (10.4%) reported having lost consciousness due to alcohol consumption in the past 12 months. The association between loss of consciousness and dementia was observed in men (HR, 2.86; 95% CI, 1.77-4.63) and women (HR, 2.09; 95% CI, 1.34-3.25) during the first 10 years of follow-up (HR, 2.72; 95% CI, 1.78-4.15), after excluding the first 10 years of follow-up (HR, 1.86; 95% CI, 1.16-2.99), and for early-onset (<65 y: HR, 2.21; 95% CI, 1.46-3.34) and late-onset (≥65 y: HR, 2.25; 95% CI, 1.38-3.66) dementia, Alzheimer disease (HR, 1.98; 95% CI, 1.28-3.07), and dementia with features of atherosclerotic cardiovascular disease (HR, 4.18; 95% CI, 1.86-9.37). The association with dementia was not explained by 14 other alcohol-related conditions. With moderate drinkers (1-14 U/wk) who had not lost consciousness as the reference group, the HR for dementia was twice as high in participants who reported having lost consciousness, whether their mean weekly consumption was moderate (HR, 2.19; 95% CI, 1.42-3.37) or heavy (HR, 2.36; 95% CI, 1.57-3.54).

Conclusions and Relevance: The findings of this study suggest that alcohol-induced loss of consciousness, irrespective of overall alcohol consumption, is associated with a subsequent increase in the risk of dementia.

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Series: JAMA network open
ISSN: 2574-3805
ISSN-E: 2574-3805
ISSN-L: 2574-3805
Volume: 3
Issue: 9
Article number: e2016084
DOI: 10.1001/jamanetworkopen.2020.16084
Type of Publication: A1 Journal article – refereed
Field of Science: 3142 Public health care science, environmental and occupational health
Funding: The IPD-Work consortium (PI Dr Kivimäki) has received funding from NordForsk (70521, the Nordic Research Programme on Health and Welfare), the UK Medical Research 10 Council (MRC S011676), the Academy of Finland (311492), the Helsinki Institute of Life Science (H970), and the US National Institutes on Aging (NIA R01AG056477, RF1AG062553). The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Copyright information: This is an open access article distributed under the terms of the CC-BY License. © 2020 Kivimäki M et al. JAMA Network Open.