AUTHOR=Bae Heewon , Kang Min Ju , Ha Sang-Won , Jeong Da-Eun , Lee Kiwon , Lim Seungui , Min Jin-Young , Min Kyoung-Bok 

TITLE=Association of plasma amyloid-β oligomerization with theta/beta ratio in older adults

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=15

YEAR=2023

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2023.1291881

DOI=10.3389/fnagi.2023.1291881

ISSN=1663-4365

ABSTRACT=<sec id="sec1"><title>Background</title><p>Oligomeric Aβ (OAβ) is a promising candidate marker for Alzheimer’s disease (AD) diagnosis. Electroencephalography (EEG) is a potential tool for early detection of AD. Still, whether EEG power ratios, particularly the theta/alpha ratio (TAR) and theta/beta ratio (TBR), reflect Aβ burden—a primary mechanism underlying cognitive impairment and AD. This study investigated the association of TAR and TBR with amyloid burden in older adults based on MDS-OAβ levels.</p></sec><sec id="sec2"><title>Methods</title><p>529 individuals (aged ≥60 years) were recruited. All participants underwent EEG (MINDD SCAN, Ybrain Inc., South Korea) and AlzOn™ test (PeopleBio Inc., Gyeonggi-do, Republic of Korea) for quantifying MDS-OAβ values in the plasma. EEG variables were log-transformed to normalize the data distribution. Using the MDS-OAβ cutoff value (0.78 ng/mL), all participants were classified into two groups: high MDS-OAβ and low MDS-OAβ.</p></sec><sec id="sec3"><title>Results</title><p>Participants with high MDS-OAβ levels had significantly higher TARs and TBRs than those with low MDS-OAβ levels. The log-transformed TBRs in the central lobe (β = 0.161, <italic>p</italic> = 0.0026), frontal lobe (β = 0.145, <italic>p</italic> = 0.0044), parietal lobe (β = 0.166, <italic>p</italic> = 0.0028), occipital lobe (β = 0.158, <italic>p</italic> = 0.0058), and temporal lobe (beta = 0.162, <italic>p</italic> = 0.0042) were significantly and positively associated with increases in MDS-OAβ levels. After adjusting for the Bonferroni correction, the TBRs in all lobe regions, except the occipital lobe, were significantly associated with increased MDS-OAβ levels.</p></sec><sec id="sec4"><title>Conclusion</title><p>We found a significant association of MDS-OAβ with TBR in older adults. This finding indicates that an increase in amyloid burden may be associated with an increase in the low-frequency band and a decrease in the relatively high-frequency band.</p></sec>