Aging
Social Isolation and Risk of Dementia: Do Race-Ethnicity and Gender Matter? Zhiyong Lin* Zhiyong Lin
Social isolation has emerged as a significant psychosocial determinant of dementia risk in older adults. However, limited research has examined how this association varies across racial-ethnic groups and by gender. To address this knowledge gap, we leveraged longitudinal data from the Health and Retirement Study (HRS) (2000–2016) to investigate the relationship between social isolation and incident dementia among non-Hispanic White, non-Hispanic Black, and Hispanic adults aged 65 years and older. Additionally, we assessed potential gender heterogeneity within each racial-ethnic group. Using survival analyses, we observed that social isolation was associated with an increased hazard of dementia among non-Hispanic White and Black individuals, independent of gender. However, no statistically significant association was detected among Hispanic older adults. Stratified analyses further revealed that socially isolated Black adults exhibited the highest dementia risk across all subgroups, highlighting the compounded vulnerability of this population. Gender disparities in dementia risk were evident only among older adults who were not socially isolated. Notably, as levels of social isolation increased, the dementia risk converged for men and women, indicating that social isolation may act as a risk equalizer across genders. Mediation analyses identified socioeconomic resources (e.g., income, education) and health-related factors (e.g., comorbidities, depressive symptoms) as significant pathways linking social isolation to dementia risk among non-Hispanic White and Black adults. These findings suggest that the observed associations are partially explained by structural inequities and cumulative health disadvantages, which exacerbate the impact of social isolation on cognitive decline. Our results underscore the critical role of social isolation as a modifiable risk factor for dementia and emphasize the need for public health strategies targeting vulnerable populations. Culturally tailored interventions to reduce social isolation and promote social engagement, particularly among non-Hispanic Black older adults, may serve as effective mechanisms for mitigating dementia risk and addressing health disparities.