Coronary artery calcium, brain function and structure: the AGES-Reykjavik Study

Area of Science:

• Neuroscience
• Cardiology
• Gerontology

Background:

• Cardiovascular risk factors are known to affect cognitive function in older adults.
• The relationship between coronary atherosclerosis burden and brain structure/function remains understudied.

Purpose of the Study:

• To investigate the association between coronary artery calcification (CAC) and cognitive function and brain structure in an older population.
• To determine if brain pathology mediates the relationship between CAC and cognitive outcomes.

Main Methods:

• Cross-sectional analysis of the Age, Gene, Environment Susceptibility (AGES)-Reykjavik Study cohort.
• Coronary artery calcification (CAC) measured by CT; cognitive function assessed via a test battery; dementia diagnosed using international guidelines.
• Brain MRI used to quantify brain volumes, lesions, infarcts, and microbleeds; multivariate models adjusted for demographic and vascular risk factors.

Main Results:

• Higher CAC scores correlated with increased likelihood of dementia, lower cognitive scores, reduced brain tissue volumes (gray matter, white matter), and more brain lesions (infarcts, microbleeds, white matter lesions).
• Associations between cognitive performance/dementia and CAC were significantly reduced after adjusting for brain lesion volumes and tissue volumes, suggesting mediation by brain pathology.

Conclusions:

• In a population-based sample, a greater atherosclerotic burden (CAC) is associated with poorer cognitive performance and dementia.
• Brain pathology, including reduced brain volumes and increased lesions, significantly mediates the link between coronary atherosclerosis and cognitive impairment.