Alzheimer’s Disease Awareness Month: Why does it affect Hispanics and Black Americans severely?
More non-Hispanic Whites are living with Alzheimer’s and other dementias than any other racial or ethnic group in the US because non-Hispanic Whites are the largest racial/ethnic group in the country. However, older African-Americans and Hispanics/Latinos are disproportionately more likely than older Whites to have Alzheimer’s or other dementias, according to health experts.
Most studies indicate that older Black Americans are about twice as likely to have Alzheimer’s or other dementias as older White Americans, suggests a report by the Alzheimer’s Association. Some studies also indicate older Hispanics/Latinos are about one-and-one-half-times as likely to have Alzheimer’s or other dementias as older Whites. “However, Hispanics/Latinos comprise a very diverse group in terms of cultural history, genetic ancestry, and health profiles, and there is evidence that prevalence may differ from one specific Hispanic/Latino ethnic group to another, for example, Mexican Americans compared with Caribbean Americans,” explain authors.
Based on data for Medicare beneficiaries age 65 and older, it has been estimated that Alzheimer’s or another dementia had been diagnosed in 10.3% of Whites, 12.2% of Hispanics/Latinos, and 13.8% of African-Americans. While the rates of diagnosis were higher among Blacks than among Whites, “according to prevalence studies that detect all people who have dementia irrespective of their use of the healthcare system, the rates should be even higher for Blacks,” writes the research team.
There are fewer data from population-based cohort studies regarding the national prevalence of Alzheimer’s and other dementias in racial and ethnic groups other than Whites, Blacks, and Hispanics/Latinos. However, a study examining electronic medical records of members of a large health plan in California indicated that dementia incidence — determined by the presence of a dementia diagnosis in members’ medical records — was highest in Blacks, intermediate for Latinos and Whites, and lowest for Asian-Americans.
A follow-up study with the same cohort showed heterogeneity within Asian-American subgroups, but all subgroups studied had lower dementia incidence than Whites. A recent systematic review of the literature found that Japanese Americans were the only Asian-American subgroup with reliable prevalence data and that they had the lowest prevalence of dementia compared with all other ethnic groups.
The US Centers for Disease Control and Prevention (CDC) says that Hispanic and African-Americans in the US will see the largest increases in Alzheimer’s disease and related dementias between 2015 and 2060. It is estimated that by 2060, the number of Alzheimer’s disease cases may rise to about 14 million people, with minority populations being affected the most. While cases among Hispanics are projected to increase seven times over current estimates, the agency says that cases among Blacks will increase four times over today’s estimates.
What are the possible reasons?
Understanding the disparities in Alzheimer’s disease and related dementias is the first step toward developing prevention strategies and targeting services to those most at risk for developing the disease, say experts.
The face of Alzheimer’s is changing, largely because the primary risk factor for it is advanced age. By 2030, the number of Latinos age 65 and older are predicted to grow by 224% and the number of African-Americans will have grown by 114%, compared to 65% among non-Hispanic Whites. Senator Amy Klobuchar also said in 2019 that African-Americans and the Latino community will represent nearly 40% of the 8.4 million American families affected by Alzheimer’s disease by 2030.
The Alzheimer’s Association reasons that the higher prevalence of Alzheimer’s in minority racial and ethnic groups compared with Whites appears to be due to a higher incidence of dementia in these groups. “Despite some evidence that the influence of genetic risk factors on Alzheimer’s and other dementias may differ by race, genetic factors do not appear to account for the large differences in prevalence or incidence among racial groups,” it adds.
Variations in medical conditions, health-related behaviors, and socioeconomic risk factors across racial groups likely account for most of the differences in risk of Alzheimer’s and other dementias. “Health conditions such as cardiovascular disease and diabetes, which are associated with an increased risk for Alzheimer’s and other dementias, are believed to account for these differences, as they are more prevalent in Black and Hispanic/Latino people. Socioeconomic characteristics, including lower levels and quality of education, higher rates of poverty, and greater exposure to adversity and discrimination, may also increase risk in black/African American and Hispanic/Latino communities, and may in turn contribute to the health conditions mentioned,” the analysis emphasizes.
There is also evidence that missed diagnoses of Alzheimer’s and other dementias are more common among older Blacks and Hispanics/Latinos than among older Whites. A study indicates despite a higher risk for Alzheimer’s and dementia, Blacks and Latinos living with these conditions are less likely than non-Hispanic Whites to receive a diagnosis from a provider. “Despite the higher prevalence, African Americans and Hispanics with dementia are, on average, less likely than non-Hispanic Whites to have been diagnosed with the condition. Moreover, African-Americans and Hispanics with dementia often experience a longer delay between their family members’ initial awareness of signs and symptoms of dementia and receipt of a diagnosis,” it says.
Preventable hospitalizations and medical costs
Based on Medicare administrative data from 2010 to 2015, preventable hospitalizations represented 23.5% of the total hospitalizations for individuals with Alzheimer’s or other dementias. African-American older adults had a substantially higher proportion of preventable hospitalizations (32%) compared with Hispanic/Latino and white older adults (22%).
In a separate analysis of Medicaid beneficiaries with a diagnosis of Alzheimer’s that included both Medicaid and Medicare claims data, researchers found significant differences in the costs of care by race and ethnicity. These results demonstrated that Blacks had significantly higher costs of care than Whites or Hispanics/Latinos, primarily due to more inpatient care and more comorbidities. “These differences may be attributable to later-stage diagnosis, which may lead to higher levels of disability while receiving care, delays in accessing timely primary care, lack of care coordination, duplication of services across providers; or inequities in access to care,” write authors.
Research needed to understand reasons behind disparity
Experts emphasize that while the field of Alzheimer’s has made great gains over the years in understanding the brain changes associated with the disease and how the disease progresses, much of the research to date has not included sufficient numbers of Blacks, Hispanics/Latinos, Asian Americans/Pacific Islanders, and Native Americans to be representative of the US population.
“A fuller understanding of Alzheimer’s — from its causes to how to prevent it, how to manage it, and how to treat it — depends on crucial factors. Among these factors is the inclusion of participants from diverse racial and ethnic groups in all realms of Alzheimer’s research. Consistent with studies of other top 10 causes of death, studies of Alzheimer’s disease in underrepresented ethnic and racial groups are relatively sparse,” suggest researchers. They add, “This reflects the urgent need for current and future research to include increased numbers of Blacks, Hispanics/Latinos, Asian Americans/Pacific Islanders and Native Americans in clinical trials, observational studies and other investigations so everyone benefits from advances in Alzheimer’s science.”
Accordingly, experts have called for additional research involving individuals from underrepresented ethnic and racial groups to gain a comprehensive understanding of Alzheimer’s disease. “Because some studies find Blacks and Hispanics/Latinos to be at increased risk for Alzheimer’s, the underrepresentation of these populations hampers the conduct of rigorous research to understand these health disparities. More studies, especially those involving population-based cohorts, are necessary to draw conclusions about the prevalence of Alzheimer’s and other dementias in different racial groups and subgroups,” they recommend.
The CDC suggests that older adults, especially Hispanic, and African-Americans, who are experiencing symptoms of memory loss, should have an assessment performed by their healthcare provider. “Doing this early can help focus efforts on timely care for patients and their caregivers. It also provides the opportunity to rule out other possible reasons for memory loss, such as medication side effects, stress, or vitamin deficiencies,” says the agency.