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February 12, 2002

Prevalence, Incidence, and Cumulative Risk of Alzheimer's Disease Reported Higher in African-American Community

Washington, D.C. — Alzheimer’s disease appears to be more prevalent among African-Americans—with estimates ranging from 14 percent to almost 100 percent higher than the disease’s prevalence among whites—according to a new report* prepared by the Alzheimer’s Association> and released today by the Congressional Black Caucus.

The report brings together for the first time an accumulating body of evidence about the scope and nature of Alzheimer’s disease in African-Americans. “Each scientific study is important research on its own, but when put together with other studies the magnitude of the crisis becomes clear,” said Orien Reid, chair of the Alzheimer’s Association Board of Directors.

“Alzheimer’s disease is a ‘silent epidemic’ that has slowly invaded the African-American community before most of us were even aware of its symptoms and its impact. These studies are sending us a clear wake-up call,” said Reid. “Now, the epidemic has reached crisis proportions. We must mobilize all of the resources we can find to get it under control before it overwhelms us.”

The Alzheimer’s Association calls on the federal government to:

• Appropriate an additional $200 million in fiscal year 2003 for Alzheimer research across the National Institutes of Health, and $1 billion in total funding by fiscal year 2004.

• Establish and fund a program through the Centers for Disease Control to expand community outreach efforts, translate research results to public health practice, and develop a system to accurately report the incidence and prevalence of Alzheimer’s disease.

• Reauthorize the Alzheimer state matching grant program at the Administration on Aging and convert it from a demonstration project to a 50-state program designed to expand and reach underserved communities dealing with Alzheimer’s disease.

Research highlighted in the report suggests that:

The prevalence, incidence, and cumulative risk of Alzheimer’s disease appears to be much higher in African-Americans.

• Age-specific prevalence of dementia has been found to be 14 percent to 100 percent higher in African-Americans. (While the rates vary among studies, three out of four report these higher prevalence rates.)

• Among African-Americans, the cumulative risk of dementia among first-degree relatives of persons with Alzheimer’s disease is 43.7 percent.

• For spouses (who share environmental but not genetic backgrounds), the cumulative risk is 18.4 percent. These findings, reported in January 2002, are based on family histories of the largest number of African-American families ever studied for Alzheimer’s disease.

The number of African-Americans entering age of risk (65 and older) is growing rapidly.

• Age is a key risk factor for Alzheimer’s disease in all racial and ethnic groups. Over 10 percent of all persons over 65, and nearly half of those over 85 have Alzheimer’s disease.

• The number of African-Americans age 65 and over will more than double by 2030, from 2.7 million in 1995 to 6.9 million by 2030.

• The number of African-Americans age 85 and over is growing almost as rapidly, from 277,000 in 1995 to 638,000 in 2030, and will increase more than fivefold between 1995 and 2050 when it will reach 1.6 million.

Genetic and environmental risk factors for Alzheimer’s disease seem different in African-Americans but have not been well studied.

• Genetic risk factors seem different in African-Americans and white Americans. APOE genotype alone does not explain the increased frequency of Alzheimer’s disease in older African-Americans.

• Vascular disease may be a particularly powerful factor in the prevalence of Alzheimer’s among African-Americans.

  • Data from a large-scale longitudinal study indicate that persons with a history of either high blood pressure or high cholesterol levels have been found twice as likely to get Alzheimer’s disease. Those with both risk factors are four times as likely to become demented.

  • Sixty-five percent of African-American Medicare beneficiaries have hypertension, compared to 51 percent of white beneficiaries. They are also at higher risk of stroke.

  • African-Americans have a 60 percent higher risk of type 2 diabetes—a condition that contributes directly to vascular disease.

  • African-Americans have a higher rate of vascular dementia than white Americans.

Screening and assessment tools and clinical trials are not designed to address the unique presentation of Alzheimer’s disease in African-Americans.

• Ethnic and cultural bias in current screening and assessment tools is well documented; as a result, African-Americans who are evaluated have a much higher rate of false-positive results. At the same time, there is substantial evidence of underreporting of dementia among African-Americans.

• African-Americans tend to be diagnosed at a later stage of Alzheimer’s disease—limiting the effectiveness of treatments that depend upon early intervention.

• African-Americans are seriously underrepresented in current clinical trials of potential treatments for Alzheimer’s disease—particularly in trials conducted by drug companies —even though evidence of genetic differences and response to drugs varies significantly by race and ethnicity.

Report: African-Americans and Alzheimer's Disease: The Silent Epidemic

*To view the report you must have Adobe Acrobat Reader® . To download Adobe Acrobat Reader® click here.

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