Biomarkers

Area of Science:

• Neurodegenerative diseases
• Biomarker research
• Obesity and metabolic health

Background:

• Obesity is a known Alzheimer's disease (AD) risk factor.
• The influence of obesity on AD blood biomarker (BBM) trajectories is not well understood.
• This study examines how obesity affects changes in plasma biomarkers and amyloid burden in AD.

Purpose of the Study:

• To investigate the relationship between obesity and Alzheimer's disease (AD) progression.
• To analyze the impact of obesity on blood biomarker (BBM) changes over time.
• To understand how obesity influences amyloid burden accumulation in AD.

Main Methods:

• Utilized plasma samples from the Alzheimer's Disease Neuroimaging Initiative (ADNI).
• Assessed global amyloid burden using (11)C-Pittsburgh Compound-B positron emission tomography (PET).
• Employed Spearman's partial correlation and linear mixed-effects regression models to analyze associations between body mass index (BMI), BBMs, and time.

Main Results:

• Higher BMI correlated with lower baseline amyloid burden, p-tau217, %p-tau217, GFAP, and NFL.
• Obese participants showed faster increases in amyloid burden (PET) and plasma p-tau217/%p-tau217 compared to non-obese individuals.
• Obesity did not show consistent associations with the rate of change in NfL or GFAP.

Conclusions:

• Obesity is associated with lower baseline AD blood biomarker levels but accelerated amyloid accumulation and p-tau217 changes.
• Findings provide crucial context for interpreting AD BBMs in obese individuals.
• This research offers insights into obesity's effects on AD pathology progression.