Correlation of Cognitive Impairment with Aβ42/40 Peripheral Blood Biomarker
Maya Salimath1, Suresh Kumar2, Hrishikesh Ambekar1, Mahith Ravulapati3, Anbu Subramanian4, Vasishta Yedlapally5
1Neurology, Young Scientist of America, 2Neurology, Headache TBI Memory Research Institute, 3neurology, 4Neurology, Young Scientists of America, 5Young Scientists of America
Objective:
Correlation of peripheral blood plasma Aβ 42/40 ratios with cognitive function decline and dementia risk, serving as a biomarker indicator of the effect of glymphatic dysfunction on dementia.
Background:
The glymphatic system clears neurotoxic proteins, including amyloid beta 42 (Aβ42) via CSF clearance during sleep. Reduced plasma Aβ42/40 ratios are associated with impaired clearance and increased dementia risk, often outperforming Aβ42 alone. Establishing its predictive role in real-world cohorts will aid early detection of neurodegeneration with simple cognitive screening test in clinic.
Design/Methods:
Retrospective cohort of 44 patients (≥50 years) with plasma Aβ42/40 values and Montreal cognitive assessment test (MoCA) score on follow-up. Cognitive functional impairment with age and APOE genotype was correlated. FDA approved serum Aβ42/40 ratios with low risk >0.17 and intermediate risk <0.17 - 0.16 and high risk < 0.15 level was considered as biomarker for Alzheimer's disease.
Results:
A significant positive association was observed between β-Amyloid 42/40 ratio and total MoCA score
(β = 65.78, SE = 29.25, p = 0.03, R² = 0.12).
For every 0.01-unit increase in amyloid ratio, MoCA score increased by approximately 0.66 points.
Participants with higher amyloid ratios (> 0.17–0.18) generally scored above the normal cognition score threshold (MoCA ≥ 26), whereas those with lower ratios (< 0.16–0.15) commonly had MoCA scores < 26, indicating mild cognitive impairment.
Conclusions:
A simple Montreal cognitive assessment is clinical tool indirectly indicate that lower β-Amyloid 42/40 ratios—reflecting greater amyloid accumulation—are associated with poorer cognitive performance (MoCA < 26). Awareness of Montreal Cognitive Assessment has linear relationship with ABeta42/20 ratio in absence of the clinical laboratory test availability. Physician may able to educate patients with confidence that the low MoCA test score is indicator of increased risk of Alzheimer's disease. Small sample size is limitation of the study, we are further analyzing data to report in future.
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