INS NYC 2024 Program

Paper

Paper Session 10 Program Schedule

02/16/2024
10:15 am - 11:40 am
Room: West Side Ballroom - Salon 3

Paper Session 10: Alzheimer's Disease


Final Abstract #3

Vascular Contributions to Cognitive Decline and Neurodegeneration Beyond the Effects of AD Pathology in Hispanic and Non-Hispanic Older Adults

Emily Matusz, University of Florida, Gainesville, United States
Jacob Fiala, University of Florida, Gainesville, United States
Shellie-Anne Levy, University of Florida, Gainesville, United States
Franchesca Arias, University of Florida, Gainesville, United States
Idaly Velez-Uribe, Florida Atlantic University, Boca Raton, United States
Melissa Armstrong, University of Florida, Gainesville, United States
Ranjan Duara, Mt. Sinai Medical Center, Miami, United States
Rosie Curiel Cid, University of Miami, Miami, United States
David Loewenstein, University of Miami, Miami, United States
Monica Rosselli, Florida Atlantic University, Boca Raton, United States
Michael Marsiske, University of Florida, Gainesville, United States
Glenn Smith, University of Florida, Gainesville, United States
Breton Asken, University of Florida, Gainesville, United States

Category: Dementia (Alzheimer's Disease)

Keyword 1: dementia - Alzheimer's disease
Keyword 2: cognitive functioning
Keyword 3: cardiovascular disease

Objective:

Integrating objective clinical testing with fluid biomarkers of Alzheimer’s disease (AD) has informed our understanding of the multiple etiologies of cognitive decline among older adults. Neuropathological correlates of dementia beyond AD pathology, such as vascular disease, may differ across subgroups of older adults with different risk factors including individuals from underrepresented racial/ethnic groups. We investigated vascular contributions to neurodegeneration (plasma neurofilament light, NfL) and memory loss beyond the effects of AD in cognitively impaired non-Hispanic/White (NHW) and Hispanic/White (HW) older adults.

Participants and Methods:

We studied 170 participants from the 1Florida Alzheimer’s Disease Research Center with cognitive impairment (Clinical Dementia Rating scale global score > 0.5). Participants self-identified as either NHW (n=76; age= 73.01+7.82, education= 16.34+3.04, female=40.8%) or HW (n=94; age= 71.06+7.42, education= 14.63+3.24, female= 63.8%). All participants completed cognitive testing, brain imaging, and blood draw. AD pathology was quantified as cortical beta-amyloid burden (Aβ-PET Centiloids, CL) and plasma P-tau181. Vascular disease was defined by total white matter hyperintensity volume adjusted for head size (WMH) and Vascular Burden Score (VBS), a 1-7 scale representing the sum of 7 cardiovascular diagnoses or risk factors.  Main outcomes were objective memory scores (Hopkins Verbal Learning Test Delayed Recall; HVLT-DR) and neurodegeneration (plasma NfL). To evaluate the added contribution of vascular disease beyond AD, we constructed hierarchical linear regression models with demographics (Block 1: age, sex, education), AD pathology (Block 2: CLs, Ptau-181) and vascular disease (Block 3: WMH, VBS).  We ran separate models for NHW and HW participants and evaluated differences in explained variance at each step (R2 change).

Results:

NHW and HW groups did not differ on AD pathology or vascular disease variables (p> .05 for all). For NHW and HW, AD pathology (Block 2) was associated with plasma NfL (NHW R2 change = 0.18, p=<.001; HW R2 change = 0.10, p=.003) and HVLT-DR (NHW R2 change = 0.10, p = .02, HW R2 change = 0.10, p = .003). The total unexplained variance in NfL and HVLT-DR after accounting for AD and demographics was greater in HW than NHW (NfL: HW = 69%, NHW = 61%; HVLT-DR: HW = 86%, NHW = 78%).  For NHW, worse vascular disease related to higher plasma NfL beyond the effects of AD (R2 change = 0.10, p=.003; β(VBS)= .258, p= .006; β(WMH)= .198, p= .042) but did not explain additional variance in memory (R2 change < .01, p=.91). Vascular contributions beyond AD were less apparent in HW participants (NfL model R2 change = 0.01, p=.44; HVLT-DR model R2 change = 0.04, p=.13). Examining individual variables, greater VBS was associated with worse memory in HW (β(VBS)= -.224, p= .044).

Conclusions:

Among cognitively impaired older adults, a significant portion of neurodegeneration and memory decline is not accounted for by demographics and AD pathology. Vascular pathophysiology may differentially relate to brain-behavior relationships, with contributions to neurodegeneration being stronger in NHW than HW. Hypotheses about the role of vascular disease in later-life brain health among underrepresented groups may not be uniform across race/ethnicity.