P121: Racial/Ethnic Disparities in Antihypertensive Medication Use and Its Causal Effect on Dementia Risk: A Longitudinal Study
Poster Presenter
Xiangxiang Jiang
PhD student
University of South Carolina United States
Objectives
This study aimed to 1) explore the potential causal effect of taking antihypertensive medication (AHM) on the risk of dementia, and 2) investigate racial/ethnic disparities in AHM use among dementia patients, and 3) examine the role of race/ethnicity in contributing to these disparities.
Method
Data from 2004-2022 Health and Retirement Study (HRS) were used. Dementia was measured based on Cognitive Status (TICS) scores. Double/debiased machine learning (DML) examined causal effects of AHMs on dementia, while the Blinder-Oaxaca decomposition assessed contributions of race/ethnicity.
Results
A longitudinal study was conducted to examine the causal effect of AHM use on dementia risks. A total of 29,360,594 individuals without dementia were included in the baseline after weighting, with 42.18% of them using AHMs. After 18 years of follow-up, 47.16% of AHM users and 38.12% of non-users developed dementia. Compared to those who did not take AHMs, AHMs users were more likely to be non-Hispanic Black (P < 0.001). Additionally, AHM users were more likely to be older, be female, have a lower level of education, experience poorer health conditions, and engage in less physical activity (P < 0.001). Results from DML analyses showed that taking AHMs reduced 9% (effect: 0.91, 95% CI: 0.84-0.97) risks of developing dementia. After categorizing dementia into mild cognitive impairment (MCI) and late-stage dementia, taking AHMs was found to have a significant protective effect against MCI (effect: 0.90, 95% CI: 0.82-0.98), but not against late-stage dementia. For causal relationships among different racial/ethnic groups, taking AHMs showed a protective effect against MCI in non-Hispanic Whites and against late-stage dementia in Hispanic individuals (P < 0.05). To examine racial/ethnic disparities in AHM use, a cross-sectional study was designed, and multivariable logistic regression was performed, adjusting for age, sex, marital status, education, health status, diabetes, cancer, heart disease, stroke, and different activity levels. We found that non-Hispanic Black patients were 82% more likely to use AHMs than non-Hispanic White patients (OR: 1.82, 95% CI: 1.50-2.20), a trend that was also observed among patients with MCI and late-stage dementia (P < 0.05). Results from Blinder-Oaxaca decomposition showed that race/ethnicity explained 39.52% of the disparities (P < 0.001) in AHM use between non-Hispanic Black and non-Hispanic White dementia patients, and 64.24% of the disparities (P < 0.001) between Hispanic and non-Hispanic White dementia patients.
Conclusion
The relationship between AHMs and dementia risk remains controversial. Previous studies differ in source populations, prevalence of confounding factors, study design, and analytical methods, making their results difficult to compare. Moreover, racial/ethnic differences in AHM effects and use, along with the contribution of race/ethnicity, remain underexplored. This study offers significant insights into the causal relationship between AHM use and dementia risk by employing the innovative DML approach. Additionally, it examines racial/ethnic disparities in AHM use among dementia patients through the application of the Blinder-Oaxaca decomposition method.
The study found that AHM use was associated with a protective effect against dementia, specifically for MCI in non-Hispanic Whites and late-stage dementia in Hispanics. Given the high prevalence of hypertension among dementia patients, these findings highlight the potential benefits of AHM use in reducing the risk of MCI and late-stage dementia. Additionally, the study found significant racial/ethnic disparities in AHM use, which is consistent with a higher prevalence of hypertension among non-Hispanic Black individuals. The Blinder-Oaxaca decomposition analysis further revealed that race/ethnicity plays a significant role in these disparities.
These findings underscore the importance of examining innovative approaches in dementia prevention and treatment strategies. Our study suggests that repurposing AHMs could be effective in reducing the risks of MCI and late-stage dementia. Understanding the factors contributing to disparities in AHM effectiveness on dementia risk is critical. Additionally, targeted interventions should prioritize equitable hypertension management and improve access to AHMs, particularly for minority groups with a higher prevalence of comorbid hypertension.
