Modifiable risk factors explain socioeconomic inequalities in dementia risk: evidence from a population-based prospective Cohort Study

Kay Deckers*, Dorina Cadar, Martin P J van Boxtel, Frans R J Verhey, Andrew Steptoe, Sebastian Köhler

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

BACKGROUND: Differences in dementia risk across the gradient of socioeconomic status (SES) exist, but their determinants are not well understood.

OBJECTIVE: This study investigates whether health conditions and lifestyle-related risk factors explain the SES inequalities in dementia risk.

METHODS: 6,346 participants from the English Longitudinal Study of Ageing were followed up from 2008/2009 until 2014/2015. We used Cox regression adjusted for age, gender, wealth/education, and clustering at the household level to examine the association between SES markers (wealth, education) and time to dementia in a structural equation model including potential mediation or effect modification by a weighted compound score of twelve modifiable risk and protective factors for dementia ('LIfestyle for BRAin health' (LIBRA) score).

RESULTS: During a median follow-up of 6 years, 192 individuals (3.0%) developed dementia. LIBRA scores decreased with increasing wealth and higher educational level. A one-point increase in the LIBRA score was associated with a 13% increase in dementia risk (hazard ratio (HR) = 1.13, 95% confidence interval 1.07-1.19). Higher wealth was associated with a decreased dementia risk (HR = 0.58, 0.39-0.85). Mediation analysis showed that 52% of the risk difference between the highest and lowest wealth tertile was mediated by differences in LIBRA (indirect effect: HR = 0.75, 0.66-0.85). Education was not directly associated with dementia (HR = 1.05, 0.69-1.59), but was a distal risk factor for dementia by explaining differences in wealth and LIBRA scores (indirect effect high education: HR = 0.92, 0.88-0.95).

CONCLUSION: Socioeconomic differences in dementia risk can be partly explained by differences in modifiable health conditions and lifestyle factors.

Original languageEnglish
Pages (from-to)549-557
Number of pages9
JournalJournal of Alzheimer's Disease
Volume71
Issue number2
Early online date14 Aug 2019
DOIs
Publication statusPublished - 2019

Keywords

  • Aging
  • cohort study
  • dementia
  • epidemiology
  • health inequalities
  • lifestyle
  • mediation
  • prevention
  • public health
  • risk factors
  • socioeconomic status
  • COGNITIVE DECLINE
  • INFORMANT QUESTIONNAIRE
  • ELDERLY IQCODE
  • SOCIAL DETERMINANTS
  • GLOBAL PREVALENCE
  • ADULT MORTALITY
  • BRAIN HEALTH
  • PREVENTION
  • LIFE
  • DISEASE

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