C-12 Race and Sex Differences in Cognitive and Neurobiological Markers of Alzheimer's Disease

Abstract

Abstract Objective Intra-Individual Cognitive Variability (IICV) previously demonstrated predictive power similar to AD biomarkers (i.e., CSF and hippocampal volume (HV) loss). Previous work suggested sex differences in relative HV and IICV. Additionally, IICV differs in whites and underrepresented racial groups (URG). Our objective was to analyze these sex differences in white and URG participants. Method Baseline neurocognitive test and neuroimaging data from 335 cognitively healthy participants with ≥2 visits enrolled in the Wisconsin ADRC Clinical Core were included. Z-scores were calculated comparing individual performance to group performance by test (Rey Auditory Verbal Learning Test (Learning and Delayed Recall), Trail Making Test (A and B), and either Boston Naming Test (BNT) or Multilingual Naming Test (MINT)). MINT scores were converted to BNT scores using the NACC Crosswalk Study. The standard deviation of z-scores across tests was calculated to determine IICV. Characteristics by race and sex were compared using Mann-Whitney, Fisher’s Exact, and Kruskal-Wallis tests. Spearman’s Rho was calculated to compare baseline IICV and relative HV. Results At baseline (Table 1), differences across racial groups in age, years of education, relative HV, and IICV were identified. Sex and racial group differences were identified (Table 2). A weak positive correlation between HV and IICV was seen in white females (Figure 1). Conclusions IICV has potential to become a cost-effective, non-invasive marker of preclinical AD. Again, correlation between HV and IICV was seen, but only in white females. Analyses suggest group differences between white and URG males and females. However, more data is needed to further explore these differences.