The influence of widowhood on amyloid positivity status in cognitively normal older adults

Abstract

AbstractBackgroundWidowhood and associated spousal bereavement is a life event that may lead to stress, loneliness, and depression. Previous research found associations between widowhood and an elevated risk of dementia. However, no direct relationship has been evidenced between widowhood and beta‐amyloid (Aβ) pathology, which is a hallmark of Alzheimer’s disease. Additionally, little is known about whether particular demographic or background factors might contribute to potential influences of widowhood on Aβ levels in older adults. Our objective was to evaluate the relationship between widowhood and Aβ positivity status in older adults, and to determine whether subgroups based on age, gender, educational attainment, or APOE ε4 status are driving effects.MethodCognitively normal (CN) subjects (n = 182) who were either widowed (including widows and widowers) or married from the Alzheimer’s Disease Neuroimaging Initiative were included in this study that underwent [18F]Florbetapir PET imaging on the baseline study visit. Multivariable logistic regression interrogated associations between widowhood status and Aβ positivity classification based on a global standardised uptake value ratio threshold of 1.11. This analysis included age, gender, APOE ε4 allele possession, education, and MMSE score as covariates. Regressions were also run in subgroups of CN subjects based on gender (male vs. female), APOE ε4 allele possession (carriers vs. non‐carriers), age (youngest, middle, oldest tertiles), and education (at least an undergraduate degree vs. no undergraduate degree).ResultIn CN subjects, there was overall no significant association between widowhood status and Aβ positivity (p = 0.114). When examining subgroups, widowhood was significantly associated with an increased risk of Aβ positivity in CN individuals with an undergraduate degree or higher (p = 0.025) or in the oldest age tertile (ages ranging from 76.3 to 89) (p = 0.024).ConclusionFindings from this cross‐sectional study indicated that a positive relationship between widowhood and in vivo Aβ neuropathology measured by PET exists specifically in those that are highly educated or undergoing advanced ageing. Whereas cognitive reserve is often hypothesised to mediate links between social isolation, depression and dementia risk, these results suggest that there may also be a direct effect on Alzheimer’s disease neuropathology.