Related Experiment Video
Updated: May 17, 2025
Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology
Published on: September 21, 2018
Cardiac autonomic function in young, healthy adults: Influence of race and sex
Ziba Taherzadeh1, Claire E Kissell1, Benjamin E Young2
1Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States.
Insights
Young Black adults do not show reduced cardiac autonomic function compared to White adults. Black men, in particular, exhibited higher cardiac baroreflex sensitivity and heart rate variability than White men.
Area of Science:
- Cardiovascular physiology
- Autonomic nervous system function
- Racial health disparities
Background:
- Non-Hispanic Black (BL) adults have a higher risk of cardiovascular disease (CVD) compared to non-Hispanic White (WH) adults.
- Cardiac autonomic function, including spontaneous cardiac baroreflex sensitivity (BRS) and heart rate variability (HRV), is a predictor of CVD.
- Limited research exists on racial differences in cardiac autonomic function, with conflicting results, and sex differences are often overlooked.
Purpose of the Study:
- To investigate racial and sex differences in cardiac autonomic function (BRS and HRV) among young, healthy adults.
- To test the hypothesis that young BL men and women would exhibit lower BRS and HRV compared to their WH counterparts.
Main Methods:
- Continuous recording of heart rate and beat-to-beat blood pressure during supine rest in 145 healthy adults (18-33 years).
- Assessment of cardiac BRS using the sequence method.
- Assessment of HRV using the root mean square of successive differences.
Main Results:
- Overall cardiac BRS was higher in BL adults compared to WH adults (P < 0.001).
- This difference was primarily driven by significantly higher BRS in BL men compared to WH men (34±16 vs. 21±9 ms/mmHg; P < 0.001).
- Greater HRV was observed in BL adults, mainly due to higher HRV in BL men compared to WH men (109±59 vs. 64±33 ms; P < 0.001). No significant differences were found between BL and WH women for BRS or HRV.
Conclusions:
- Contrary to the hypothesis, young BL adults do not exhibit reduced cardiac autonomic function compared to WH adults.
- BL men demonstrated enhanced cardiac autonomic function (higher BRS and HRV) compared to WH men.
- Reduced cardiac autonomic function, a potential risk factor for CVD, does not appear to manifest early in life among healthy BL adults.
Abstract:
Non-Hispanic Black (BL) adults living in the United States are more likely to develop cardiovascular disease (CVD) compared with their non-Hispanic White (WH) counterparts. Although measures of cardiac autonomic function [i.e., spontaneous cardiac baroreflex sensitivity (BRS) and heart rate variability (HRV)] have a predictive value for CVD, studies investigating racial differences in cardiac autonomic function are limited and have reported conflicting results. Furthermore, sex differences are often not considered despite BL women having a high prevalence of CVD. We hypothesized that young BL men and women would exhibit lower cardiac BRS and HRV compared with their WH counterparts. Heart rate and beat-to-beat blood pressure were continuously recorded during 5 min of supine rest in 145 young (18-33 yr), healthy, BL (37 men, 38 women) and WH (39 men, 31 women) adults to assess cardiac BRS and HRV. Overall cardiac BRS (sequence method) was higher in BL adults compared with WH adults (P < 0.001), which was mainly driven by differences between BL and WH men (BL men: 34 ± 16 vs. WH men: 21 ± 9 ms/mmHg, P < 0.001) compared with women (BL women: 27 ± 12 vs. WH women: 24 ± 11 ms/mmHg; P > 0.05). Likewise, greater HRV in BL adults, indexed by root mean square of successive differences, was primarily driven by BL men (BL men: 109 ± 59 vs. WH men: 64 ± 33 ms; P < 0.001) rather than BL women (P > 0.05). Thus, contrary to our hypothesis, these results support that reduced cardiac autonomic function does not manifest early in life among young BL adults.NEW & NOTEWORTHY Herein, we demonstrated that BL adults do not have lower cardiac autonomic function compared with WH adults. Rather BL men had greater spontaneous cardiac baroreflex sensitivity and heart rate variability compared with WH men while no differences were found among BL and WH women. These findings suggest that reduced cardiac autonomic function, which could increase the risk of cardiovascular disease, does not appear early in life in healthy BL adults.
Related Concept Videos
01:29Pathophysiology of Cardiac Performance
01:31Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
01:30Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...