Socioeconomic Inequalities in Cognitive Functioning Only to a Small Extent Attributable to Modifiable Health and Lifestyle Factors in Individuals Without Dementia

Article type: Research Article

Authors: Röhr, Susanne^{a; b; c; *} | Pabst, Alexander^a | Baber, Ronny^{d; e} | Engel, Christoph^{e; f} | Glaesmer, Heide^g | Hinz, Andreas^g | Schroeter, Matthias L.^{h; i} | Witte, A. Veronica^h | Zeynalova, Samira^{e; f} | Villringer, Arno^{h; i} | Löffler, Markus^{e; f} | Riedel-Heller, Steffi G.^a

Affiliations: [a] Institute of Social Medicine, Occupational Health and Public Health (ISAP), Medical Faculty, University of Leipzig, Leipzig, Germany | [b] Global Brain Health Institute (GBHI), Trinity College Dublin, Dublin, Ireland | [c] School of Psychology, Massey University, Manawatū Campus, Palmerston North, New Zealand | [d] Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany | [e] LIFE – Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany | [f] Institute for Medical Informatics, Statistics and Epidemiology (IMISE), University of Leipzig, Leipzig, Germany | [g] Department of Medical Psychology and Medical Sociology, University of Leipzig, Leipzig, Germany | [h] Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany | [i] Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany

Correspondence: [*] Correspondence to: Dr. rer. med. habil. Susanne Röhr, MSc, Institute of Social Medicine, Occupational Health and Public Health (ISAP), Medical Faculty, University of Leipzig, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany. Tel.: +49 341 9715406; E-mail:susanne.roehr@medizin.uni-leipzig.de.

Abstract: Background:There are socioeconomic inequalities in dementia risk. Underlying pathways are not well known. Objective:To investigate whether modifiable health and lifestyle factors for brain health mediate the association of socioeconomic status (SES) and cognitive functioning in a population without dementia. Methods:The “LIfestyle for BRAin health” (LIBRA) score was computed for 6,203 baseline participants of the LIFE-Adult-Study. LIBRA predicts dementia in midlife and early late life, based on 12 modifiable factors. Associations of SES (education, net equivalence income, and occupational status) and LIBRA with cognitive functioning (composite score) were investigated using adjusted linear regression models. Bootstrapped structural equation modelling (SEM) was used to investigate whether LIBRA mediated the association of SES and cognitive functioning. Results:Participants were M = 57.4 (SD = 10.6, range: 40-79) years old; 50.3% were female. Both, SES (Wald: F(2)=52.5, p < 0.001) and LIBRA (Wald: F(1)=5.9, p < 0.05) were independently associated with cognitive functioning; there was no interaction (Wald: F(2)=2.9, p = 0.060). Lower SES and higher LIBRA scores indicated lower cognitive functioning. LIBRA partially mediated the association of SES and cognitive functioning (IE: =0.02, 95% CI [0.02, 0.03], p < 0.001). The proportion mediated was 12.7%. Conclusion:Differences in cognitive functioning due to SES can be partially attributed to differences in modifiable health and lifestyle factors; but to a small extent. This suggests that lifestyle interventions could attenuate socioeconomic inequalities in cognitive functioning. However, directly intervening on the social determinants of health may yield greater benefits for dementia risk reduction.

Keywords: Cognitive function, dementia, epidemiology, lifestyle, prevention, public health, risk factors, social inequalities, socioeconomic status

DOI: 10.3233/JAD-220474

Journal: Journal of Alzheimer's Disease, vol. 90, no. 4, pp. 1523-1534, 2022