Exposure to area disadvantage across the life course and its influence on cognition and neurodegenerative pathology in later life

• Published in: Alzheimer's & dementia Vol. 19; no. S22
• Main Authors: Cartlidge, Molly R E, Liu, Yiwen, Bakolis, Ioannis, Nicholas, Jennifer M, Keuss, Sarah E, Coath, William, Cash, David M, Malone, Ian B, Sudre, Carole H, Schott, Jonathan M, Richards, Marcus
• Format: Journal Article
• Language: English
• Published: 01-12-2023
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1002/alz.076195

Background
In older adults, exposure to area disadvantage is associated with poorer cognitive performance, smaller whole brain and hippocampal volumes and cardiovascular risk. However, there is little research on the timing, accumulation and change in exposure to area disadvantage. This study aimed to investigate whether exposure to area disadvantage across the life course is associated with cognition and neurodegenerative pathology in late adulthood.
Method
Data from the MRC National Survey of Heath and Development (British 1946 birth cohort; analytical sample: n = 1,762) and a neuroimaging sub‐study (Insight 46; analytical sample: n = 447) were used. Area disadvantage was defined as the percentage of employed individuals in semi‐skilled or unskilled occupations. In the full cohort we assessed the relationship of area disadvantage at 26, 53 and 60‐64 years, cumulative area disadvantage and area disadvantage change score with cognitive performance at 69. In Insight 46 we examined associations between area disadvantage and neuroimaging outcomes (69‐71 years): whole brain, hippocampal, and ventricular volumes, amyloid status, and white matter hyperintensity volume (WMHV). All analyses were adjusted for socio‐economic and lifestyle confounders, with the neuroimaging analyses also adjusted for age at scan and total intracranial volume.
Result
Negative associations were found between exposure to area disadvantage at all ages and cognitive performance, with stronger effects at 53 and 60‐64 (Table 1). These effect sizes remained similar when adjusted for sex, father’s social class and childhood emotional symptoms, but were attenuated when further adjusted for educational attainment and childhood cognition. A negative association was found between cumulative exposure to area disadvantage and cognitive performance (Table 1), and no effect was found from change in area disadvantage. WMHV was the only neurological outcome found to be associated with area disadvantage variables (Table 2).
Conclusion
Living in a disadvantaged area across the life course is associated with poorer cognitive performance at age 69, most of this affect is accounted for by childhood cognition and educational attainment. Living in a disadvantaged area across the life course is also associated with higher WMHV, suggesting presumed cerebrovascular disease, a dementia risk factor. Further research is required to understand the mechanism driving this association.