CoChat
Sign Up
Cited by 18Dementia and Cognitive Impairment ResearchHealth disparities and outcomesSmoking Behavior and Cessation

Contribution of smoking towards the association between socioeconomic position and dementia: 32-year follow-up of the Whitehall II prospective cohort study

Open access
Raggi, Martina, Dugravot, Aline, Valeri, Linda, Machado-Fragua, Marcos D., Dumurgier, Julien, Kivimaki, Mika, Sabia, Séverine, Singh-Manoux, Archana·2022·The Lancet Regional Health - Europe
DOI 10.1016/j.lanepe.2022.100516PMC PMC9523395
Open this paper in CoChat — free accountOpen PDF

Abstract

Background: There is consistent evidence of social inequalities in dementia but the mechanisms underlying this association remain unclear. We examined the role of smoking in midlife in socioeconomic differences in dementia at older ages. Methods: Analyses were based on 9951 (67% men) participants, median age 44.3 [IQR=39.6, 50.3] years at baseline in 1985-1988, from the Whitehall II cohort study. Socioeconomic position (SEP) and smoking (smoking status (current, ex-, never-smoker), pack years of smoking, and smoking history score (combining status and pack-years)) were measured at baseline. Counterfactual mediation analysis was used to examine the contribution of smoking to the association between SEP and dementia. Findings: During a median follow-up of 31.6 (IQR 31.1, 32.6) years, 628 participants were diagnosed with dementia and 2110 died. Analyses adjusted for age, sex, ethnicity, education, and SEP showed smokers (hazard ratio [HR] 1.36 [95% CI 1.10-1.68]) but not ex-smokers (HR 0.95 [95% CI 0.79-1.14]) to have a higher risk of dementia compared to never-smokers; similar results for smoking were obtained for pack-years of smoking and smoking history score. Mediation analysis showed low SEP to be associated with higher risk of dementia (HRs between 1.97 and 2.02, depending on the measure of smoking in the model); estimate for the mediation effect was 16% for smoking status (Indirect Effect HR 1.09 [95% CI 1.03-1.15]), 7% for pack-years of smoking (Indirect Effect HR 1.03 [95% CI 1.01-1.06]) and 11% for smoking history score (Indirect Effect HR 1.06 [95% CI 1.02-1.10]). Interpretation: Our findings suggest that part of the social inequalities in dementia is mediated by smoking. Funding: NIH.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1016/j.lanepe.2022.100516

Cites

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Cardiovascular health and smoking partially mediate the relationship between socioeconomic deprivation and dementia.

    “Since cardiovascular health and smoking partially mediate the relationship between socioeconomic deprivation and dementia,(285-288)”

    From Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission (2024) · cites this paper as [288]

    The Discussion says smoking explained a modest part of socioeconomic differences in dementia. It identifies cardiovascular factors as possible additional mediators but says the study did not include other possible mediators, so it does not establish the cardiovascular-health part of the claim. The indexed passages provide section labels but no page numbers. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

The citation lists haven’t been fetched yet

References 40 · Cited by 18

Research works printed but not linked: 33

  1. [1]WHO. Risk reduction of cognitive decline and dementia: WHO guidelines. 2019. 31219687
  2. [2]Meng X D'Arcy C. Education and dementia in the context of the cognitive reserve hypothesis: a systematic review with meta-analyses and qualitative analyses PLoS One 7 6 2012 e38268 22675535 PMC3366926
  3. [3]Rusmaully J Dugravot A Moatti JP Contribution of cognitive performance and cognitive decline to associations between socioeconomic factors and dementia: a cohort study PloS Med 14 6 2017 e1002334 PMC5484463 28650972
  4. [5]Aldus CF, Arthur A, Dennington-Price A, et al. Undiagnosed dementia in primary care: a record linkage study. Southampton (UK); 2020. 32310343
  5. [7]Andrews SJ Fulton-Howard B O'Reilly P Causal associations between modifiable risk factors and the Alzheimer's phenome Ann Neurol 89 1 2021 54 65 32996171 PMC8088901
  6. [8]Rose G. Sick individuals and sick populations Int J Epidemiol 14 1 1985 32 38 3872850
  7. [9]Marmot M. Inclusion health: addressing the causes of the causes Lancet 391 10117 2018 186 188 29137870
  8. [10]Dougherty RJ Moonen J Yaffe K Smoking mediates the relationship between SES and brain volume: the CARDIA study PLoS One 15 9 2020 e0239548 PMC7505457 32956388
  9. [12]Weng PH Chen JH Chiou JM The effect of lifestyle on late-life cognitive change under different socioeconomic status PLoS One 13 6 2018 e0197676 PMC5999076 29897986
  10. [14]Nakahori N Sekine M Yamada M Tatsuse T Kido H Suzuki M. A pathway from low socioeconomic status to dementia in Japan: results from the Toyama dementia survey BMC Geriatr 18 1 2018 102 29703157 PMC5923187
  11. [17]Stringhini S Sabia S Shipley M Association of socioeconomic position with health behaviors and mortality Jama 303 12 2010 1159 1166 20332401 PMC2918905
  12. [18]Nandi A Glymour MM Subramanian SV. Association among socioeconomic status, health behaviors, and all-cause mortality in the United States Epidemiology 25 2 2014 170 177 24487200
  13. [19]Gregoraci G van Lenthe FJ Artnik B Contribution of smoking to socioeconomic inequalities in mortality: a study of 14 European countries, 1990-2004 Tob Control 26 3 2017 260 268 27122064
  14. [20]Almeida OP Hulse GK Lawrence D Flicker L. Smoking as a risk factor for Alzheimer's disease: contrasting evidence from a systematic review of case-control and cohort studies Addiction 97 1 2002 15 28 11895267
  15. [21]Sabia S Elbaz A Dugravot A Impact of smoking on cognitive decline in early old age: the Whitehall II cohort study Arch Gen Psychiatry 69 6 2012 627 635 22309970 PMC3675806
  16. [23]Cataldo JK Prochaska JJ Glantz SA. Cigarette smoking is a risk factor for Alzheimer's disease: an analysis controlling for tobacco industry affiliation J Alzheimers Dis 19 2 2010 465 480 20110594 PMC2906761
  17. [24]Otuyama LJ Oliveira D Locatelli D Tobacco smoking and risk for dementia: evidence from the 10/66 population-based longitudinal study Aging Ment Health 24 11 2020 1796 1806 31512501
  18. [25]Sabia S Marmot M Dufouil C Singh-Manoux A. Smoking history and cognitive function in middle age from the Whitehall II study Arch Internal Med 168 11 2008 1165 1173 18541824 PMC2696613
  19. [26]Jack CR Jr. Knopman DS Jagust WJ Tracking pathophysiological processes in Alzheimer's disease: an updated hypothetical model of dynamic biomarkers Lancet Neurol 12 2 2013 207 216 23332364 PMC3622225
  20. [27]Whalley LJ Dick FD McNeill G. A life-course approach to the aetiology of late-onset dementias Lancet Neurol 5 1 2006 87 96 16361026
  21. [28]VanderWeele TJ. Causal mediation analysis with survival data Epidemiology 22 4 2011 582 585 21642779 PMC3109321
  22. [29]Marmot MG Smith GD Stansfeld S Health inequalities among British civil servants: the Whitehall II study Lancet 337 8754 1991 1387 1393 1674771
  23. [30]Song Q Zhou T Sun D Panoramic smoking burden and genetic susceptibility in relation to all-cause and cause-specific mortality: a prospective study in UK Biobank Addiction 117 4 2022 1062 1070 34605583
  24. [31]Sommerlad A Perera G Singh-Manoux A Lewis G Stewart R Livingston G. Accuracy of general hospital dementia diagnoses in England: sensitivity, specificity, and predictors of diagnostic accuracy 2008-2016 Alzheimers Dement 14 7 2018 933 943 29703698 PMC6057268
  25. [32]Wilkinson T Ly A Schnier C Identifying dementia cases with routinely collected health data: a systematic review Alzheimers Dement 14 8 2018 1038 1051 29621480 PMC6105076
  26. [33]Richiardi L Bellocco R Zugna D. Mediation analysis in epidemiology: methods, interpretation and bias Int J Epidemiol 42 5 2013 1511 1519 24019424
  27. [34]Shi B Choirat C Coull BA VanderWeele TJ Valeri L. CMAverse: a suite of functions for reproducible causal mediation analyses Epidemiology 32 5 2021 e20 ee2 34028370
  28. [35]Valeri L Lin X VanderWeele TJ. Mediation analysis when a continuous mediator is measured with error and the outcome follows a generalized linear model Stat Med 33 28 2014 4875 4890 25220625 PMC4224977
  29. [36]Weuve J Tchetgen Tchetgen EJ Glymour MM Accounting for bias due to selective attrition: the example of smoking and cognitive decline Epidemiology 23 1 2012 119 128 21989136 PMC3237815
  30. [38]Winblad B Amouyel P Andrieu S Defeating Alzheimer's disease and other dementias: a priority for European science and society Lancet Neurol 15 5 2016 455 532 26987701
  31. [39]Rothman KJ Gallacher JE Hatch EE. Why representativeness should be avoided Int J Epidemio 42 4 2013 1012 1014 PMC3888189 24062287
  32. [40]Batty GD Shipley M Tabák A Generalizability of occupational cohort study findings Epidemiology 25 6 2014 932 933 25265141
  33. [41]Silverberg N Elliott C Ryan L Masliah E Hodes R. NIA commentary on the NIA-AA research framework: towards a biological definition of Alzheimer's disease Alzheimers Dement 14 4 2018 576 578 29653608

Authors
Raggi, M., Dugravot, A., Valeri, L., Machado-Fragua, M. D., Dumurgier, J., Kivimaki, M., Sabia, S., & Singh-Manoux, A.
Affiliations
  • Inserm (FR)
  • Harvard University (US)
ORCID
Venue
The Lancet Regional Health - Europe
Publisher
Elsevier BV
Published
2022-12
Volume
23
Pages
100516
ISSN
2666-7762 (ISSN-L)
DOI
10.1016/j.lanepe.2022.100516
PMC
PMC9523395
OpenAlex
W4297472920
Cited by
18
References
40
Citations by year
2026: 5 · 2025: 6 · 2024: 5 · 2023: 1 · 2022: 1
FWCI
2.12
Type
journal article
Language
en
Open access
Licence
Locations
  • The Lancet Regional Health - Europe (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • UCL Discovery (University College London) (submittedVersion)
  • Työväentutkimus Vuosikirja (submittedVersion)
Funders
  • Wellcome Trust (S011676, R024227, 221854, 221854/Z/20/Z, R01AG056477)
  • National Institutes of Health (S011676, R024227)
  • Medical Research Council (S011676, MR/S011676/1, R024227, MR/R024227/1)
  • National Institute on Aging (RF1AG062553, R01AG056477)
Topics
  • Health Sciences › Medicine › Psychiatry and Mental health › Dementia and Cognitive Impairment Research
  • Social Sciences › Health › Health disparities and outcomes
  • Health Sciences › Medicine › Physiology › Smoking Behavior and Cessation
Keywords
smoking, socioeconomic position, dementia, health disparities, mediation analysis, smoking history, former smokers, midlife, Whitehall II cohort

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review