CLINICOPATHOLOGIC DIFFERENCES WITHIN ALZHEIMER’S DISEASE CASES FROM THE FLORIDA AUTOPSIED MULTI-ETHNIC (FLAME) STUDY

Despite the projected increase in dementia prevalence and growing proportion of ethnic minorities in the U.S., little is known about clinicopathologic differences in ethnoracially diverse individuals with autopsy-confirmed Alzheimer's disease (AD). Of particular interest is the applicability of the “Hispanic mortality paradox” in the context of AD. This epidemiological phenomenon has previously suggested comparable or more advantaged longevity despite socioeconomic disadvantage relative to Caucasians/non-Hispanic Whites. Our study sought to examine demographic risk variables for AD dementia, clinical progression, and neuropathologic outcomes within the Florida Autopsied Multi-Ethnic (FLAME) cohort. Individuals from the FLAME study were grouped according to their self-reported ethnoracial status as Hispanic (n=67), African-American/Black (n=19), and Caucasian/White non-Hispanic (n=1539). Clinical history was reviewed to abstract antemortem information (see Table), including occupation that was converted to a 6-point scale ranging from 0 (no job) to 6 (highly skilled). The proportion of individuals surviving from age onset of cognitive complaints until age at death (i.e., disease duration) is graphically displayed (see Figure). We did not observe differences in the frequency of females, APOE ε4 status, or in age at death. Differences in education approached significance with Hispanics observed to have a lower education; however, job level score did not differ. Significant group-wise differences across ethnoracially diverse AD cases consisted of: (1) Hispanics had a more frequent family history of cognitive impairment, an earlier age onset, longer disease duration, and lower MMSE proximal to death; (2) African-Americans/Blacks had a shorter disease duration, higher frequency of clinical AD dementia diagnosis, and less advanced Braak stage; (3) Hispanic and African-Americans/Blacks in this AD cohort had a lower brain weight. We did not observe a difference in Thal amyloid phase, TDP-43 positivity, or coexisting LBD.