LAUSR

Background: Understanding how increasing urbanisation affects health inequalities with ageing has gained growing interest [1], but the synergistic influence of environmental and individual factors on cognitive ageing is yet unclear [2]. The present study investigated the impact on cognitive health of living in more or less densely populated areas and having or not a disability. Methods: Using data from a large cohort study and the Census, we explored crosssectional variations in global cognition, memory, and executive functions for 4,127 Irish people aged 50+ based on the level of population density of the electoral division of residence (approximately 20km2) and the presence of disabilities (ADL and/or IADL). Regression models controlled for socio-demographic, health and lifestyle covariates. Results: Overall higher cognitive scores were found in more rather than less populated electoral divisions (10+ vs. <10 persons per hectare) after controlling for covariates. However, participants with disabilities living in the most densely populated areas had the poorest performance in terms of MoCA (p = 0.005), immediate recall (p = 0.02) and executive functions (p = 0.009). Demographic or lifestyle circumstances did not affect these results. Conclusions: While highly populated areas present more opportunities for mental stimulation which can benefit cognitive health, having a disability may increase the individual’s susceptibility to environmental stressors (e.g. crowding), with a negative impact on cognition. The findings highlight the importance of considering how the lived environment fits individual resources or limitations to better understand geographical variations in cognitive ageing. References 1. Giles-Corti B, Vernez-Moudon A, Reis R et al. City planning and population health: a global challenge. The Lancet 2016 Sep 23 [cited 2016 Nov 29];388(10062. 2. Cassarino M, Setti A. Complexity As Key to Designing Cognitive-Friendly Environments for Older People. Front Psychol 2016; 7: 1329.