Sex differences in cognitive trajectories and practice effects in a cohort of older Londoners: the role of risk factors
Author(s)
Type
Journal Article
Abstract
Background
Sex differences in cognitive abilities have been reported; however, the underlying reasons remain unclear.
Objective
To (i) investigate sex differences in cognitive performance, (ii) evaluate the contributions of established dementia risk factors to these differences, and (iii) examine the role of non-modifiable risk factors on sex differences in cognitive performance.
Methods
Among 964 cognitively unimpaired participants (aged 60–85) of the UK CHARIOT-PRO Main Study, we assessed cross-sectional and longitudinal associations, over up to 3 years of follow-up, between sex and cognitive performance, using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).
Results
Sex differences, mostly favoring women were observed at baseline across almost all RBANS indices including the total scale (Cohen's d = 0.3, adjusted mean difference in score = −5.4, p < 0.001). Sex differences were observed in Practice effects (PEs), with men showing less PE in almost all cognitive domains including the total scale (adjusted 1.3, p = 0.002). Greater sex differences in PEs, were documented among the ‘older’ participants in two out of five cognitive domains including the immediate memory index (mean difference: older (69–85 years) group = −3.2, p = 0.002); younger (60–68 years) group = −0.8, p = 0.4). Sex differences were more pronounced among ‘Apolipoprotein-Ꜫ4 -carriers’ in three out of five domains including the total scale (mean difference in carriers = −2.6, p = 0.002); non-carriers = −0.7, p = 0.3).
Conclusions
Sex differences in cognition and PE were observed after adjusting for risk factors associated with Alzheimer's disease. Future studies should also consider the effects of sex on non-modifiable risk factors and PEs to identify potential ‘masked’ neuropathology.
Sex differences in cognitive abilities have been reported; however, the underlying reasons remain unclear.
Objective
To (i) investigate sex differences in cognitive performance, (ii) evaluate the contributions of established dementia risk factors to these differences, and (iii) examine the role of non-modifiable risk factors on sex differences in cognitive performance.
Methods
Among 964 cognitively unimpaired participants (aged 60–85) of the UK CHARIOT-PRO Main Study, we assessed cross-sectional and longitudinal associations, over up to 3 years of follow-up, between sex and cognitive performance, using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).
Results
Sex differences, mostly favoring women were observed at baseline across almost all RBANS indices including the total scale (Cohen's d = 0.3, adjusted mean difference in score = −5.4, p < 0.001). Sex differences were observed in Practice effects (PEs), with men showing less PE in almost all cognitive domains including the total scale (adjusted 1.3, p = 0.002). Greater sex differences in PEs, were documented among the ‘older’ participants in two out of five cognitive domains including the immediate memory index (mean difference: older (69–85 years) group = −3.2, p = 0.002); younger (60–68 years) group = −0.8, p = 0.4). Sex differences were more pronounced among ‘Apolipoprotein-Ꜫ4 -carriers’ in three out of five domains including the total scale (mean difference in carriers = −2.6, p = 0.002); non-carriers = −0.7, p = 0.3).
Conclusions
Sex differences in cognition and PE were observed after adjusting for risk factors associated with Alzheimer's disease. Future studies should also consider the effects of sex on non-modifiable risk factors and PEs to identify potential ‘masked’ neuropathology.
Date Issued
2025-05-07
Date Acceptance
2025-03-24
Citation
Journal of Alzheimer's Disease, 2025
ISSN
1387-2877
Publisher
SAGE Publications
Journal / Book Title
Journal of Alzheimer's Disease
Copyright Statement
© The Author(s) 2025. This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
License URL
Identifier
10.1177/13872877251339833
Subjects
Alzheimer's disease
cognition
gender
risk factors
practice effects
sex differences
Publication Status
Published online
Article Number
13872877251339833
Date Publish Online
2025-05-07