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Ethnic and socioeconomic determinants of dementia risk: A nested case‐control study in the population of East London
Author(s) -
Bothongo Phazha LK,
Jitlal Mark,
Parry Eve,
Foote Isabelle F,
Waters Sheena,
Dobson Ruth,
Noyce Alastair J,
Bestwick Jonathan P,
Marshall Charles R
Publication year - 2020
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 - 10.1002/alz.037869
Subject(s) - dementia , demography , medicine , socioeconomic status , body mass index , odds ratio , ethnic group , population , nested case control study , relative risk , gerontology , risk factor , logistic regression , environmental health , confidence interval , disease , sociology , anthropology
Background The influence of ethnicity and socioeconomic status on dementia risk, and the extent to which this is mediated by known risk factors remain incompletely understood. We addressed this issue using health records data from the diverse and deprived population of East London (<50% White and >50% in the most deprived quintile of the UK). Method We performed a nested case‐control study in over 1,000,000 East London inhabitants. We identified 4137 cases of all cause dementia, and matched on age and gender to controls with ratio 1:4. Logistic regression was used to calculated odds ratios (ORs) for exposures of ethnicity and UK Index of Multiple Deprivation (IMD), before and after inclusion in the model of established modifiable risk factors (type II diabetes, hypertension, smoking, body mass index, depression and hearing loss). In order to reflect the relative importance of known modifiable risk factors in this deprived multiracial population, we calculated weighted population attributable fractions (PAF) for each factor. Result Risk of dementia was higher in the Black and South Asian groups relative to White (ORs (95%CI) Black 1.43 (1.31, 1.56), South Asian 1.17 (1.06, 1.29)). Risk of dementia was reduced in all IMD quintiles relative to the most deprived (ORs (95%CI) 2nd 0.71 (0.66, 0.77), 3rd 0.52 (0.44, 0.60), 4th 0.71 (0.53, 0.94), 5th 0.59 (0.38, 0.87)). The effects of ethnicity and deprivation persisted after adjusting for known risk factors. Weighted PAFs for modifiable risk factors were notably higher in this population for depression (9.2%) and diabetes (6.2%) than those estimated in the Lancet Commission meta‐analyses (4% and 1.2% respectively). Conclusion Membership of non‐White ethnic groups and socioeconomic deprivation are important determinants of dementia risk, with effects larger than many of the more established risk factors. These effects cannot be completely accounted for by known modifiable risk factors and further work is required to establish the responsible mechanisms. Depression and diabetes are of greater relative importance, and should be prioritised as targets for dementia prevention in more diverse and deprived populations.