Race and APOE-e4 Status Differences in the Association between Loneliness and Cognitive Decline.

OBJECTIVE: To examine race and APOE-e4 status differences in the longitudinal associations between loneliness and cognitive decline.

METHODS: The study sample is comprised of participants (N = 7,696, 64% Black participants and 36% White participants) from the Chicago Health and Aging Project, a population-based cohort study. Mixed effects regression models were conducted to examine the longitudinal associations between loneliness on global cognitive function and individual tests of cognitive function. Models were also stratified by race and APOE-e4.

RESULTS: A greater percentage of Black participants (17%) reported loneliness at baseline visit compared to White participants (12%). Black and White participants who were lonely individuals had a similar rate of decline in global cognitive function at 0.075 (95% Confidence Interval (CI) = -0.082, -0.068) standard deviation unit (SDU) per year for Black participants and at 0.075 (95% CI = -0.086, -0.063) SDU per year for White participants. Lonely participants with APOE-e4 had a higher rate of global cognitive decline at -0.102 (95% CI = -0.115, -0.088) SDU per year than for lonely participants without APOE-e4 at -0.052 (95% CI = -0.059, -0.045) SDU per year.

CONCLUSIONS: The burden of loneliness and its relation to cognitive decline is higher among participants with APOE-e4, compared to those without APOE-e4. Loneliness is associated with cognitive decline in both Black and White participants.