Social isolation and cognitive function: focusing on race/ethnic differences from the nhats study

Abstract Social isolation has negative associations with various health outcomes including cognitive function. However, limited research exists delineating the effect of social isolation on cognition using population-based longitudinal data. Moreover, little is known whether there are any race/ethnic differences in this social isolation-cognition relationship. We examined the effects of social isolation on cognitive function and explored the moderating role of race/ethnicity using longitudinal data of 4381 older adults from two waves of NHATS (2015 and 2018). Social isolation was measured by addressing four domains of network and integration: (a) marriage or partnership, (b) family and friends, (c) church participation, and (d) club participation (score range: 0 - 6). A higher score indicates more social isolation. Cognitive function was measured using the composite score of three domains: memory, orientation, and executive function (range: 0 - 33), with higher scores indicating better cognitive function. Repeated-measures ANOVA showed a significant relationship between social isolation and cognitive function. Specifically, the greater the social isolation, the lower the cognitive function. We found significant differences in cognitive function scores across race/ethnic groups. Non-Hispanic White showed higher cognitive function than non-Hispanic black, Hispanics, and other races. Non-Hispanic black and other races also showed significantly higher scores than Hispanics. The findings also showed that the cognitive function score significantly decreased over a 4- year period. There was no moderating effect of race/ethnicity found between social isolation and cognitive function. Interventions are needed to reduce social isolation by facilitating social participation in community activities, thereby protecting against cognitive decline.