Contribution of life course cardiovascular risk factors to racial disparities in dementia incidence

Erin L Ferguson; Eric Vittinghoff; Adina Zeki Al Hazzouri; Norrina Allen; Annette Fitzpatrick; Kristine Yaffe

doi:10.3389/frdem.2023.1215904

Contribution of life course cardiovascular risk factors to racial disparities in dementia incidence

Front Dement. 2023 Jun 29:2:1215904. doi: 10.3389/frdem.2023.1215904. eCollection 2023.

Authors

Erin L Ferguson¹, Eric Vittinghoff¹, Adina Zeki Al Hazzouri², Norrina Allen³, Annette Fitzpatrick⁴, Kristine Yaffe^{1

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Affiliations

¹ Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States.
² Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY, United States.
³ Department of Internal Medicine, Northwestern University, Chicago, IL, United States.
⁴ Departments of Family Medicine, Epidemiology, and Global Health, School of Public Health, University of Washington, Seattle, Washington, DC, United States.
⁵ Department of Psychiatry and Behavioral Sciences, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States.
⁶ Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States.

Abstract

Background: Racial disparities in dementia outcomes persist in the United States. Targeting modifiable risk factors, including cardiovascular risk factors (CVRFs), is a conceivable way to reduce health disparities. Life course CVRFs are often higher in non-White adults and are associated with risk of dementia, but it is unknown whether they contribute to racial disparities in dementia and cognition.

Methods: Using a pooled cohort of 4,159 White and 939 Black participants aged 65-95 years, we conducted a mediation analysis to estimate the proportional effect of race on dementia that is explained by four CVRFs imputed over the life course (20-49, 50-69, and 70-89 years of age): body mass index, fasting glucose, systolic blood pressure, and low-density lipoprotein cholesterol.

Results: Compared to White participants, Black participants had greater risk of dementia (adjusted OR = 1.37; 95% CI: 1.17-1.60). BMI and fasting glucose over the life course were significant mediators of the effect of race on dementia risk, mediating 39.1% (95% CI: 10.5-67.8%) and 8.2% (95% CI: 0.1-16.2%) of the effect, adjusted for sex and age. All four CVRFs together were also significant mediators of the effect of race on scores on global cognition and processing speed, accounting for approximately 11% of the effect.

Conclusions: We found that CVRFs across the life course partially explain disparities in dementia risk and cognition in late-life. Improved prevention and treatment of CVRFs across the life course may be important to reduce health disparities for dementia.

Keywords: health disparity populations; heart disease risk factors; imputation; life course; mediation analysis; risk factors.

Grants and funding

This work was supported by the following grants from the National Institutes of Health, National Institute on Aging (R01AG071916 and RF1AG054443). The funding organization or sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. CARDIA is supported by contracts HHSN268201800003I, HHSN268201800004I, HHSN268201800005I, HHSN268201800006I, and HHSN268201800007I from the National Heart, Lung, and Blood Institute (NHLBI). MESA is supported by contracts 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, and N01-HC-95169 from the National Heart, Lung, and Blood Institute, and by grants UL1-TR-000040, UL1-TR-001079, and UL1-TR-001420 from the National Center for Advancing Translational Sciences (NCATS). CHS is supported by contracts HHSN268201200036C, HHSN268200800007C, HHSN268201800001C, N01HC55222, N01HC85079, N01HC85080, N01HC85081, N01HC85082, N01HC85083, N01HC85086, 75N92021D00006, and grants U01HL080295, and U01HL130114 from the National Heart, Lung, and Blood Institute (NHLBI), with additional contribution from the National Institute of Neurological Disorders and Stroke (NINDS). Additional support was provided by R01AG023629 from the National Institute on Aging (NIA). A full list of principal CHS investigators and institutions can be found at CHS-NHLBI.org. Health ABC study is supported by National Institute on Aging (NIA) Contracts N01-AG-6–2101; N01-AG-6–2103; N01-AG-6–2106; NIA grant R01-AG028050, and NINR grant R01-NR012459. Health ABC was funded in part by the Intramural Research Program of the NIH, National Institute on Aging.