Aging
The impact of life course socioeconomic status on incident dementia among the oldest-old in the LifeAfter90 Study Hilary L. Colbeth* Hilary Colbeth Rachel L. Peterson Kristen M. George Alexander Ivan B. Posis Rifat B. Alam Paola Gilsanz Dan M. Mungas Maria M. Corrada Rachel A. Whitmer
Background Low socioeconomic status (SES) in early and late life is associated with lower late-life cognition among the oldest-old. Less is known about life course trajectories of SES in association with dementia risk among diverse populations over 90 years.
Methods This prospective cohort from the LifeAfter90 Study (2018-2022) included 430 participants (mean age=92.1±2.2 years; 24% Asian; 19% Black; 19% LatinX; 7% Multiracial/Other; 30% White). Participants with only mild cognitive impairment were excluded. Childhood and late-life SES were self-reported across three domains: financial, cultural, and social capital, based on Bourdieu’s forms of capital. Financial capital is an economic indicator based on income, cultural capital reflects education-based generational gains, and social capital indicates access to resources from social networks. We estimated subdistribution risks in the presence of the competing risk of death for dementia incidence by each domain, adjusting for age, gender, and race/ethnicity. We then examined if associations differed by either childhood residence outside the United States or birth in a Stroke Belt state.
Results We observed 94 incident dementia cases. Participants with consistently low or high to low trajectories had an increased risk of dementia compared to those with consistently high financial capital (Figure 1). Those with mixed social capital trajectories had an increased risk of dementia compared to those consistently high. There was no evidence of an association between cultural capital trajectories and increased dementia incidence. There were no differences by childhood residence or birth state in the associations of financial (p-interaction=0.19), cultural (p=0.99), or social capital (p=0.28) with dementia incidence.
Conclusions Lower financial capital in early and late life is associated with greater incident dementia risk among adults aged 90+, regardless of US childhood residence or birth in the Stoke Belt.
