Concomitant vascular and neurodegenerative pathologies double the risk of dementia

Mahmoud Reza Azarpazhooh; Abolfazl Avan; Lauren E Cipriano; David G Munoz; Luciano A Sposato; Vladimir Hachinski

doi:10.1016/j.jalz.2017.07.755

Concomitant vascular and neurodegenerative pathologies double the risk of dementia

Alzheimers Dement. 2018 Feb;14(2):148-156. doi: 10.1016/j.jalz.2017.07.755. Epub 2017 Sep 30.

Authors

Mahmoud Reza Azarpazhooh¹, Abolfazl Avan², Lauren E Cipriano³, David G Munoz⁴, Luciano A Sposato⁵, Vladimir Hachinski⁶

Affiliations

¹ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada; Department of Neurology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.
² Department of Neurology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Neurology, Academic Medical Center, Amsterdam, The Netherlands.
³ Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Ivey Business School, Western University, London, Ontario, Canada.
⁴ Department of Pathology and Laboratory Medicine, University of Toronto & Department of Laboratory Medicine, and Keenan Research Centre for Biomedical Research, The Li Ka Shing Knowledge Institute, St Michael's Hospital Toronto, Ontario, Canada.
⁵ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Stroke, Dementia and Heart Disease Laboratory, Western University, London, Ontario, Canada; Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.
⁶ Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada. Electronic address: Vladimir.Hachinski@lhsc.on.ca.

PMID: 28974416
DOI: 10.1016/j.jalz.2017.07.755

Abstract

Introduction: The relative contributions of vascular and degenerative pathology to dementia are unknown. We aim to quantify the proportion of dementia explained by potentially preventable vascular lesions.

Methods: We systematically searched for population-based cohorts before February 2017 reporting clinicopathological data for individuals with and without dementia. We calculated the summary proportion and absolute risk of dementia comparing subjects with and without the pathology.

Results: We identified 10 studies comprising 2856 subjects. Vascular-type pathology and mixed pathology are respectively two and three times more likely in demented patients. The summary proportion of dementia is 77%-86% in subjects with mixed degenerative and vascular pathology and 45% in subjects with pure Alzheimer-type pathology.

Discussion: Patients with mixed pathologies have nearly twice the incremental risk of dementia compared with patients with only Alzheimer-type lesions. Consequently, many cases of dementia could be prevented or delayed by targeting the vascular component.

Keywords: Aging; Alzheimer's disease; Macroinfarct; Meta-analysis; Microinfarct; Mixed dementia; Plaques; Prevention; Risk; Systematic review; Tangles; Vascular cognitive impairment; Vascular dementia.

MeSH terms

Aged
Aged, 80 and over
Cohort Studies
Databases, Bibliographic / statistics & numerical data
Dementia / etiology*
Female
Humans
Male
Middle Aged
Neurodegenerative Diseases / complications*
Neurodegenerative Diseases / pathology*
Vascular Diseases / complications*
Vascular Diseases / pathology*