The population of African Americans older than 65 years and therefore
at risk for Alzheimer disease (AD) and other dementias is increasing even
faster than the white population in this age group.1,2
In general, studies have found rates of dementia in African Americans to be
comparable with or higher than in whites.3-5
However, this issue is far from clear. Vascular dementia (VaD), which is more
prevalent among African Americans than whites,6
is usually attributed to the higher prevalence of cardiovascular risk factors.
For example, according to data from the Third National Health and Nutrition
Examination Survey from 1988-1991, 24% of the US population has hypertension.7 The age-adjusted national prevalence is higher in
non-Hispanic African Americans (32.4%) overall, and even higher for African
Americans in the southeast region of the country: 35% for African American
men, 37.7% for African American women.8 The
definitive diagnosis of VaD is more imprecise than that of AD, and the prevalence
of mixed dementias (AD and VaD) is more elusive,9
even with the advent of more precise clinical criteria.9-11