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[O1–04–05]: SOCIOECONOMIC INEQUALITIES IN DEMENTIA RISK EXPLAINED BY MODIFIABLE RISK FACTORS: FINDINGS FROM THE ENGLISH LONGITUDINAL STUDY OF AGEING
Author(s) -
Deckers Kay,
Cadar Dorina,
Boxtel Martin P.J.,
Verhey Frans R.J.,
Steptoe Andrew,
Koehler Sebastian
Publication year - 2017
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.07.056
Subject(s) - dementia , socioeconomic status , mediation , gerontology , medicine , demography , ageing , psychology , disease , environmental health , population , sociology , political science , law
Background:Differences in dementia risk across the gradient of socioeconomic status exist, but its determinants are not under- stood. Therefore, the aim of this study was to investigate whether differences in socioeconomic status are associated with incident dementia and whether this association is ex- plained by health- and lifestyle-related factors. Methods: 6,346 participants (mean age 1⁄4 64.9, SD 1⁄4 8.6; 55.7% fe- male) were followed up for a maximum of 7 years. Dementia was based on self-reported physician-diagnosed dementia or Alzheimer’s disease at each wave and a score of 3.38 or higher on the shortened version of the IQ-CODE. Socioeco- nomic status was based on wealth defined as household net of debt and included cash, investments, savings and physical wealth. Health- and lifestyle-related factors were captured by a poly-environmental risk score, called the ‘Lifestyle for BRAin Health’ (LIBRA) index. LIBRA consists of a weighted sum score of twelve modifiable risk and protective factors for cognitive decline or dementia. Higher scores indicate higher risk (range -5.9 to +10.3). Cox regression adjusted for age, gender and education and clustering at the household level examined the association between socioeconomic status and time to dementia in a structural equation model including po- tential mediation or effect modification by LIBRA. Results: LIBRA scores decreased with increasing wealth. During a me- dian follow-up of 6.0 years, 192 individuals (3.0%) developed dementia. High socioeconomic status was associated with a decreased dementia risk (highest versus lowest tertile: HR 1⁄4 0.54, 95%CI 1⁄4 0.36-0.79), but this was substantially attenuated after adjusting for differences in LIBRA scores (highest versus lowest tertile: HR 1⁄4 0.77, 95%CI 1⁄4 0.51-1.16). Mediation anal- ysis showed that 58% of the risk difference between the highest and the lowest tertile of wealth was mediated by differences in LIBRA. A one point increase in LIBRA was associated with a 13% increase in dementia risk (HR 1⁄4 1.13, 95%CI 1⁄4 1.07- 1.19) on average (no interaction). Conclusions: Differences in dementia risk between socioeconomic groups can be partly attributed to differences in treatable health- and lifestyle related factors. Future public health campaigns for dementia risk reduction should try hard to reach out to this vulnerable group.