The effect of race and co‐morbidities on Alzheimer's disease based on Medicare data

Abstract

Introduction Alzheimer's disease (AD) incidence is thought to be higher among Black than White individuals. Methods We studied the US Medicare population from 2000 to 2018. Cox regression was used to determine the roles of race and co‐morbidities for AD incidence. Results We studied 11,880,906 Medicare beneficiaries, with 774,548 AD cases. Hazard ratios (HRs) by increasing numbers of co‐morbidities (1–7) were 1.51, 2.00, 2.55, 3.16, 2.89, 4.77, and 5.65. Among those with no co‐morbidities, Black individuals had a lower rate than those who are White (HR = 0.69), while among those with one more co‐morbidities, Black individuals had a higher rate (HR = 1.19). The presence of hypertension increased AD rates by 14% for White individuals, but 69% for those who are Black. Discussion More co‐morbidities was strongly associated with higher AD rates. The higher rates for Black versus White individuals was apparent only for those with co‐morbidities and appears driven both by more co‐morbidities, and the greater effect of hypertension. Highlights Black individuals have been shown to have higher Alzheimer's disease (AD) rates than those who are White. Some co‐morbidities are known to increase AD risk. Among those In Medicare data with no co‐morbidities, Black individuals have less risk than those who are White. Among those with co‐morbidities, Black individuals have higher rates than those who are White. Hypertension results in a much stronger increase in AD risk for Black versus White individuals.

We must be clear that the root cause of racial disparities in Alzheimer's disease is racism

“…We read with interest the paper by Steenland et al (May 2023), 1 which describes the effects of race and comorbidities on Alzheimer's disease (AD) using Medicare data. While we agree that studying racial disparities in the prevalence of Alzheimer's disease is important, we are concerned that the authors' framing of the research question, methodology, and the interpretation of the study's findings perpetuate false and harmful stereotypes regarding inherent physiological differences between persons from different racial groups.…”

“…," and that "this interaction between race and hypertension is the main reason Black individuals have higher rates [of AD] than White adults, after adjusting for co-morbidities." 1 The phrasing used here could be interpreted as placing blame on the Black body, especially considering the authors do not mention the well-established role of structural and systemic racism in creating and sustaining the differential burden of hypertension and cardiovascular disease carried by marginalized groups. 5 There are numerous studies that have found associations between residential segregation, exposure to air pollution, experiences of discrimination, and poor educational quality with the risk of dementia.…”