Social determinants of health and cognitive performance of older adults living in rural communities: The Three Villages Study

Objectives: There is limited information on factors associated with poor cognitive performance in rural settings of Low- and Middle-Income Countries. Using the Three Villages Study Cohort, we assessed whether social determinants of health (SDH) play a role in cognitive performance among older adults living in rural Ecuador. Methods: Atahualpa, El Tambo and Prosperidad residents aged >= 60 years received measurement of SDH by means of the Gijon Scale together with a Montreal Cognitive Assessment (MoCA). The association between SDH and cognitive performance (dependent variable) was assessed by generalized linear models, adjusted for demographics, years of education, cardiovascular risk factors, symptoms of depression and biomarkers of structural brain damage. Results: We included 513 individuals (mean age: 67.9 +/- 7.3 years; 58% women). The mean score on the Gijon scale was 9.9 +/- 2.9 points, with 237 subjects classified as having a high social risk (>= 10 points). The mean MoCA score was 19.6 +/- 5.4 points. Locally weighted scatterplot smoothing showed an inverse linear relationship between SDH and MoCA scores. SDH and MoCA scores were inversely associated in linear models adjusted for clinical covariates (beta: -0.17; 95% C.I.: -0.32 to -0.02; p = 0.020), neuroimaging covariates (beta: -0.17; 95% C.I.: -0.31 to -0.03; p = 0.018), as well as in the most parsimonious model (beta: -0.16; 95% C.I.: -1.30 to -0.02; p = 0.026). Conclusions: Study results provide robust evidence of an inverse association between SDH and cognitive performance. Interventions and programs aimed to reduce disparities in the social risk of older adults living in underserved rural populations may improve cognitive performance in these individuals.