Sex Differences in Alzheimer's Disease

Keith R. Laws; Karen Irvine; Tim M. Gale

Disclosures

Curr Opin Psychiatry. 2018;31(2):133-139. 

In This Article

Abstract and Introduction

Abstract

Purpose of review: Women are more impacted by Alzheimer's disease than men – they are at significantly greater risk of developing Alzheimer's disease, and recent research shows that they also appear to suffer a greater cognitive deterioration than men at the same disease stage. The purpose of this article is to review recent studies on examining sex differences in cognitive function in Alzheimer's disease.

Recent findings: We searched electronically for articles, reviews and meta-analyses published between 1/2016 and 12/2017 and identified 298 articles on sex differences in cognition in Alzheimer's disease. The key themes to emerge were sex differences in cognitive function, risk factors, resilience, and cognitive reserve.

Summary: Evidence is steadily and increasingly accumulating to confirm the poorer cognitive outcome for women than men with Alzheimer's disease. Although small in size, the effects occur across a broad range of cognitive domains including visuospatial, verbal, episodic memory, and semantic memory – some of which typically reveal a sex-related processing advantage for healthy women. Explanations have been linked to a variety of factors including differences in cognitive reserve, resilience, as well as genetics (apolipoprotein ε4) and functional and structural brain changes. Sex-related differences in risk factors, resilience, cognitive reserve, and rates of deterioration have implications for clinical practice.

Introduction

Dementia affects around 47 million people worldwide and the incidence is expected to double every 20 years.[1] Around 60–80% of all dementia cases are caused by Alzheimer's disease[2] and two-thirds of those diagnosed with Alzheimer's disease are women (https://www.dementiastatistics.org/statistics/prevalence-by-gender-in-the-uk/). Indeed, on many metrics, women appear to be more impacted by Alzheimer's disease than men. Meta-analytic evidence from large population studies derived from the United States, Europe, and Asia indicates that women are at significantly greater risk of developing Alzheimer's disease, though not other dementias[3] and this increased incidence is not due to women having a longer life-span.[4] Furthermore, neuroimaging[5] and postmortem[6] studies point to potentially different underlying Alzheimer's disease pathology between the sexes.

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