Circulating apoE4 protein levels from dried blood spots predict cognitive function in a large population-based survey...

Area of Science:

• Neuroscience
• Genetics
• Biochemistry

Background:

• The apolipoprotein E (APOE) ε4 allele is a known risk factor for cognitive impairment.
• The impact of circulating apoE4 protein levels on cognition in carriers remains unclear.
• Factors influencing circulating apoE4 levels are not well understood.

Purpose of the Study:

• To investigate the relationship between circulating apoE4 protein levels and cognitive function in adults aged 50+.
• To identify predictors of circulating apoE4 protein levels.
• To explore how health and lifestyle factors modulate the risk associated with the APOE ε4 allele.

Main Methods:

• Assayed apoE4 protein levels in dried blood spots from 12,532 adults (aged 50+).
• Utilized regression analyses to assess cognitive impairment likelihood and predictors of apoE4 levels.
• Quantified apoE4 protein using specific binding assays.

Main Results:

• APOE ε4 allele presence, indicated by protein binding, was detected in 28.4% of participants.
• Individuals with the APOE ε4 allele were more likely to experience cognitive impairment, with risk increasing with age.
• Higher circulating apoE4 protein levels were associated with a reduced likelihood of cognitive impairment among carriers.
• Antihypertensive medication use was a predictor of apoE4 protein levels.

Conclusions:

• The apoE4 isoform is associated with both protein deficiency and poorer cognitive outcomes.
• The level of circulating apoE4 protein in ε4 carriers modulates the observed association with cognition.
• Cardiovascular factors, such as antihypertensive medication use, influence circulating apoE4 protein levels.