Subjective Cognitive Decline and Objective Cognitive Trajectories in Older Hispanics/Latinos

Project Summary/Abstract This project is directly aligned with the NIA’s strategic goals of 1) developing improved approaches for the early detection and diagnosis of disabling illnesses and age-related debilitating conditions and 2) identifying appropriate strategies for disease, illness, and disability prevention and healthy aging among the underserved.

As the older adult population continues to grow, it is expected that an increasing number of seniors will be living with Alzheimer’s disease and related dementias. As such, it is imperative to identify early risk markers of cognitive decline prior to symptom manifestation. Although Hispanics/Latinos (henceforth referred to as Hispanics) are at

increased risk for mild cognitive impairment compared to non-Hispanic Whites, research investigating early risk markers in this growing and underserved segment of the United States (U.S.) population is lacking. One potential early risk marker of Alzheimer’s disease is subjective cognitive decline (SCD), which is used to describe self-

reported perceived changes in cognitive function compared to a previous state. Although the expression, reporting, and predictive value of SCD may vary due to factors such as cultural/ethnic background, acculturation, and education level, little research has been conducted outside of non-Hispanic White cohorts. In fact, most

existing SCD research with Hispanics has been conducted in Spain, whose population is very culturally different than Hispanics living in the U.S. The proposed study will help advance SCD research by characterizing the cognitive and biomarker correlates of SCD in U.S. Hispanics cross-sectionally, and by establishing its predictive

value for cognitive change over three years. To achieve this, we will prospectively administer a validated SCD questionnaire, a culturally sensitive cognitive test battery, mood questionnaires (i.e., depression), and culturally- relevant measures that may influence SCD to older Hispanics with normal cognition (N=100) or mild cognitive

impairment (N=100). We will also obtain SCD reports from participant’s informants to determine its differential ability to predict cognitive decline. Participant recruitment will leverage on existing cohorts at two sites: The University of California San Diego Shiley-Marcos Alzheimer’s Disease Research Center (ADRC) and the

1Florida ADRC. We will investigate if self and informant SCD reports are associated with concurrent, objective cognitive function (adjusting for relevant covariates) and examine if baseline SCD reports predict change in cognition over 3-years. Moreover, we will use existing biomarkers collected by the ADRCs, as well as novel

blood-based biomarkers, to investigate if SCD is associated with amyloid-β and apolipoprotein E ε4 allelic status. Furthermore, we will investigate if acculturation, health literacy, country of origin, and language of testing, as well as demographic variables (age, sex, years of education) influence SCD reporting. Findings will characterize the

cognitive and biomarker profile and predictive value of SCD in U.S. Hispanics, help refine SCD measurement, and identify individual differences in SCD reporting that may confer greater risk for decline.