Inflammation and Cognitive Decline: A Population-Based Cohort Study Among Aging Adults With Atrial Fibrillation

Area of Science:

• Cardiology
• Neurology
• Gerontology

Background:

• Atrial fibrillation (AF) is linked to cognitive decline, but the underlying mechanisms are unclear.
• Inflammatory markers like C-reactive protein (CRP) may increase blood-brain barrier (BBB) permeability, potentially causing neuroinflammation.
• This study investigates the association between CRP, cognitive impairment, and mortality in older adults with AF.

Purpose of the Study:

• To examine the relationship between baseline C-reactive protein (CRP) levels and cognitive impairment in aging adults with atrial fibrillation (AF).
• To assess the association between CRP levels and mortality in this cohort.
• To identify cognitive trajectories and their relationship with CRP levels, considering sex differences.

Main Methods:

• Analysis of data from 2109 adults (≥45 years) with prevalent AF from the REGARDS cohort.
• Measurement of plasma CRP at baseline and annual cognitive status using the Six-Item Screener.
• Application of competing risks Cox proportional hazards regression and latent class growth models, with adjustments for sex.

Main Results:

• A doubling of CRP was associated with increased mortality (HR 1.13) but not incident cognitive impairment (HR 0.98).
• Two cognitive trajectories were identified: 91% stable and 9% progressive decline.
• Men with higher CRP showed increased odds of progressive cognitive decline (OR 1.09), unlike women (OR 1.04).

Conclusions:

• Elevated CRP levels are associated with cognitive impairment in aging men with AF.
• Inflammation-mediated blood-brain barrier dysfunction is a potential pathway linking AF to cognitive decline.
• Sex-specific differences exist in the association between CRP and cognitive decline in AF patients.