HAI Book 2025 - Flipbook - Page 146
Dong, Yiwen
19
The association between amyloid and physical activity in a racially
diverse cohort of older adults
Yiwen Dong1, Qiong Wu1, Davneet Minhas2, Charles M. Laymon2,3, Victor Villemagne4, Oscar
Lopez5, Beth Snitz5, Marissa A. Gogniat5, Nancy W. Glynn6, Dana Larisa Tudorascu1,4, Ann D.
Cohen4
1
Department of Biostatistics and Health Data Science, School of Public Health, Pittsburgh, PA, US
Department of Radiology, School of Medicine, Pittsburgh, PA, US
3
Department of Bioengineering, Swanson School of Engineering, Pittsburgh, PA, US
4
Department of Psychiatry, School of Medicine, Pittsburgh, PA, US
5
Department of Neurology, School of Medicine, Pittsburgh, PA, US
6
Department of Epidemiology, School of Public Health, Pittsburgh, PA, US
2
Introduction: Physical activity (PA) is proposed to be an effect modifier of Alzheimer9s disease (AD) risk, however,
it remains unclear if this modification is a result of a direct impact on AD pathophysiology or through indirect
mechanisms, like increased cognitive reserve or reduced cardiometabolic risk. In this study of racially diverse
older adults, we explored the association of PA and amyloid deposition measured by [11C] Pittsburgh Compound
B-PET (PiB).
Methods: 128 participants (mean age 65.3 years, 68.0% female, 47.7% African American) received PiB imaging on
2 different scanners (Siemens HR+/Biograph mCT). PA data were collected via wrist-worn Actiwatch and
processed using ActiLife. The association between PiB FreeSurfer-derived SUVRs and PA outcomes was
assessed by Spearman's correlation, with 95% confidence intervals using bootstrapping. Results were compared
before and after harmonization using ComBat to account for scanner differences. The associations between A´
deposition in various brain regions and PA were further explored using generalized linear models (GLMs) including
an interaction term with race, adjusting for age, sex, ApoE4, and education.
Results: In this study, the average global SUVR was 1.2. PA, measured using maximum steps count per minute
(mean 99.2), was significantly associated with a decreased A´ deposition and was consistent before and after
harmonization (Table 1). GLMs estimates revealed that one-unit increase in maximum steps (100 steps/minute)
was associated with 13%, 14%, 15%, and 18% lower A´ deposition in the lateral temporal, parietal, posterior
cingulate, and precuneus regions, respectively (p < 0.05 for all models).
Conclusion: The study demonstrates that higher maximum step count is associated with lower amyloid
deposition in a racially diverse cohort. Further, there were no differences observed before and after scanner
harmonization in results and effect sizes. Future work will explore additional PA variables, such as different PA
intensity levels, to determine their effect on AD pathology.
HAI2025 - 146
