Resting Cerebral Blood Flow and Ethnic Differences in Heart Rate Variability: Links to Self-Reports of Affect and...

Area of Science:

• Neuroscience
• Cardiovascular Physiology
• Psychophysiology

Background:

• Reduced high-frequency heart rate variability (HF-HRV) is a known risk factor for cardiovascular disease (CVD).
• African Americans (AA) have a higher CVD risk but paradoxically exhibit greater HF-HRV than European Americans (EA).
• The "Cardiovascular Conundrum" suggests differences in regional cerebral blood flow (CBF) associations with HF-HRV may explain this disparity.

Purpose of the Study:

• To investigate ethnic differences in the association between regional cerebral blood flow (CBF) and HF-HRV.
• To explore the relationship between CBF, HF-HRV, and affect regulation strategies in European Americans (EA) and African Americans (AA).

Main Methods:

• Pooled data from 452 EA and 102 AA participants.
• Examined associations between CBF in 8 regions of interest (cingulate, insula, amygdala) with HF-HRV, mean heart rate (HR), and Coefficient of Variation (CoV).
• Utilized Bayesian statistics and analyzed self-reported affect and emotion regulation.

Main Results:

• CBF, particularly in the anterior cingulate cortex (ACC), positively correlated with HF-HRV and CoV in EA.
• Conversely, CBF in the ACC was negatively associated with HF-HRV and CoV in AA.
• Emotion regulation strategies showed ethnic differences: reappraisal positively correlated with HF-HRV in AA; anger suppression/non-expression associated with higher HF-HRV in AA, while outward anger direction was linked to lower HF-HRV in AA.

Conclusions:

• The anterior cingulate cortex (ACC) plays a differential role in regulating HF-HRV between EA and AA.
• Higher HF-HRV in AA may represent a compensatory mechanism, potentially linked to emotion regulation differences.
• Findings highlight the importance of considering ethnicity in understanding cardiovascular health and neural regulation.