Abstract
BACKGROUND: The effects of late-life subjective poverty on brain health are understudied. We aimed to investigate the association between duration of subjective poverty after age 64 and subsequent cognitive function and decline in China. METHODS: Data were from 4118 adults aged ≥64 at baseline in the population-based China Longitudinal Healthy Longevity Survey (CLHLS), 2005-2018. The duration of subjective poverty was measured from self-rated economic status relative to neighbors in 2005, 2008, and 2011 (never; one time point; two or three time points). Cognitive function was assessed by the Chinese Mini-Mental State Exam (CMMSE; range: 0-30) in 2011, 2014, and 2018. We fitted attrition-weighted, multivariable mixed-effects Tobit regression models to examine the relationship between duration of subjective poverty from 2005 to 2011 and subsequent cognitive function and decline from 2011 to 2018. RESULTS: A total of 2675 (64.96%) participants never reported subjective poverty over the period 2005-2011, 930 (22.58%) participants reported subjective poverty at one time point, and 513 (12.46%) reported subjective poverty at two or three time points. Compared to those who never reported subjective poverty, participants experiencing subjective poverty at one time point (β = -0.95, 95% CI: -1.48 to -0.41) and two or three time points (β = -2.01; 95% CI: -2.73 to -1.29) had lower CMMSE scores in 2011, indicating a dose-response relationship. Individuals with a longer duration of subjective poverty had a slower rate of decline in CMMSE scores than those never in subjective poverty (β = 1.44; 95% CI: 0.20 to 2.68 for 2018 X Two or three time points). CONCLUSION: Subjective poverty in late life may have unique and cumulative contributions to cognitive aging among older adults in China. The lower level of initial cognitive function but slower rate of cognitive decline observed for those with greater subjective poverty is consistent with theories of cognitive reserve and empirical evidence from Western settings on other socioeconomic markers.