Decreased plasma C-reactive protein levels in APOE ε4 allele carriers

Abstract

Objective: Apolipoprotein E (APOE) ε4 allele is a well-established risk factor in Alzheimer's disease (AD). Here, we assessed the effects of APOE polymorphism on cardiovascular, metabolic, and inflammation-related parameters in population-based cohorts. Methods: Association of cardiovascular, metabolic, and inflammation-related parameters with the APOE polymorphism in a large Finnish Metabolic Syndrome in Men (METSIM) cohort and Finnish Geriatric Intervention study to prevent cognitive impairment and disability (FINGER) were investigated. Brain-specific effects were addressed in postmortem brain samples. Results: Individuals carrying the APOE ε4 allele displayed significantly elevated serum/plasma LDL cholesterol and apolipoprotein B levels. APOE ε3ε4 and ε4ε4 significantly associated with lower levels of plasma high-sensitivity C-reactive protein (hs-CRP). Plasma amyloid-β 42 (Aβ42) and reduced hs-CRP levels showed an association independently of the APOE status. Interpretation: These data suggest that the APOE ε4 allele associates with lower levels of hs-CRP in individuals without dementia. Moreover, Aβ42 may encompass anti-inflammatory effects reflected by reduced hs-CRP levels.