Neural control of cardiovascular function in black adults: implications for racial differences in autonomic regulation

Abstract

Black adults are at increased risk for developing hypertension and cardiovascular and chronic kidney disease and have greater associated morbidity/mortality than white adults who are otherwise demographically similar. Despite the key role of the autonomic nervous system in the regulation of cardiovascular function, the mechanistic contributions of sympathetic nerves to racial differences in cardiovascular dysfunction and disease remain poorly understood. In this review, we present an update and synthesis of current understanding regarding the roles of autonomic neural mechanisms in normal and pathophysiological cardiovascular control in black and white adults. At rest, many hemodynamic and autonomic variables, including blood pressure, cardiac output, and sympathetic nerve activity, are similar in healthy black and white adults. However, resting sympathetic vascular transduction and carotid baroreflex responses are altered in ways that tend to promote increased vasoconstriction and higher blood pressure, even in healthy, normotensive black adults. Acute sympathoexcitatory maneuvers, including exercise and cold pressor test, often result in augmented sympathetic and hemodynamic responses in healthy black adults. Clinically, although mechanistic evidence is scarce in this area, existing data support the idea that excessive sympathetic activation and/or transduction into peripheral vasoconstriction contribute importantly to the pathophysiology of hypertension and chronic kidney disease in black compared with white adults. Important areas for future work include more detailed study of sympathetic and hemodynamic reactivity to exercise and other stressors in male and female black adults and, particularly, sympathetic control of renal function, an important area of clinical concern in black patients.

Sex differences in cardiac vagal reactivation from the end of isometric handgrip exercise and at the onset of muscle metaboreflex isolation

“…Second, we did not screen and report race/ethnicity in this study, although the majority of the participants are Latin-Americans and Caucasians. Thus, our findings cannot be extrapolated to all racial/ethnic groups, as significant racial differences have been observed in cardiovascular parameters (Drew et al, 2020;Young et al, 2020). Third, we have employed ultra-short-term HRV measures and hence one could argue that this could be a limitation.…”

Assessment of baroreceptor reflex sensitivity in young obese Saudi males at rest and in response to physiological challenges

“…Our subjects (both normal weight and overweight/obese group) behaved in a manner similar to the European participants in response to submaximal exercise by exhibiting a reduction in BRS in postexercise period. Given that there are differences in regulation of physiological variables such as heart rate variability, blood pressure, responses to challenges such as exercise and responses to drugs for treatment of certain common ailments such as hypertension (Drew et al., 2020; Foulds et al., 2015; Hill et al., 2015; Hill & Thayer, 2019; Johnson, 2008), it is important to study the basic physiological differences in various ethnicities. Our study is a first step in this direction where we have studied the resting BRS and the effect of physiological challenges on BRS in individuals of Arab ethnicity.…”

Influence of sex on heightened vasoconstrictor mechanisms in the non‐Hispanic black population

“…Accordingly, we will focus on mechanisms of impaired vascular function, and more specifically, on proposed mechanisms of heightened vasoconstriction in this population. Previous reviews have focused on the impaired vasodilator capacity in BL individuals so interested readers are referred to these excellent reviews 14–16 . It is important to note that much of the work that we will discuss in this mini‐review is collected in relatively young, otherwise healthy college‐aged BL men and women.…”

“…Previous reviews have focused on the impaired vasodilator capacity in BL individuals so interested readers are referred to these excellent reviews. [14][15][16] It is important to note that much of the work that we will discuss in this mini-review is collected in relatively young, otherwise healthy college-aged BL men and women. The findings of alterations in vascular responsiveness in multiple vascular beds, even at this young age, [17][18][19][20][21] highlights the need to gain a better understanding of the associated mechanisms.…”