Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis

Area of Science:

• Neuroscience
• Cardiology
• Gerontology

Background:

• Autonomic nervous system (ANS) function and brain morphology are interconnected, influencing health and disease.
• Previous research on heart rate variability (HRV) and cortical thickness (CT) associations yielded inconsistent results, potentially due to age and sex differences and small sample sizes.

Purpose of the Study:

• To investigate the association between ANS function (HRV and HR) and brain morphology (CT) across the lifespan.
• To address limitations of previous studies by conducting a large-scale mega-analysis incorporating sex and aging effects.

Main Methods:

• Mega-analysis of pooled data from 20 international groups (N=1,218, ages 12-87).
• Standardized assessment of cortical thickness (CT) and resting-state heart rate (HR) and heart rate variability (HRV).
• Statistical analysis to examine associations between HRV, HR, CT, age, and sex.

Main Results:

• A significant decline in both HRV and CT was observed with increasing age.
• Orbitofrontal cortex CT explained additional variance in HRV, independent of age and sex, suggesting a link between declining HRV and reduced orbitofrontal CT in aging.
• No significant association was found between CT and HR, highlighting the specificity of the HRV-CT relationship.

Conclusions:

• The findings suggest that age-related decline in HRV may be associated with reduced orbitofrontal cortical thickness.
• Greater CT may be crucial for maintaining cardiac regulation through the ANS, or conversely, higher cardiac vagal activity (reflected by HRV) may slow brain atrophy.
• The study highlights the neurovisceral connection with implications for healthy aging and longevity, warranting further longitudinal investigation.