Author(s)

Peter L. Latchman¹, Gregory J. Gates², Robert Thiel¹, Robert S. Axtell¹, Weili Zhu³, Ally Morin-Viall¹, Tianhong Yue¹, Qin Yang¹, Kenneth Gardner⁴, Ronald E. De Meersman⁵

¹Exercise Science Department, Southern Connecticut State University, New Haven, CT, USA.
²Department of Pediatrics, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY, USA.
³Capital University of Physical Education and Sports, Beijing, China.
⁴G. C. Foster College of Physical Education and Sport, Spanish Town, Jamaica.
⁵College of Medicine, American University of Antigua, Osbourn, Antigua and Barbuda.

Purpose: African-American men (AAM) have a greater risk of hypertension (HTN) than Caucasian men (CM). To reduce this risk, determining the differences in mechanisms involved in HTN and understanding the relationship between these mechanisms and factors affecting blood pressure (BP) in AAM and CM is necessary. One such mechanism is spontaneous baroreflex sensitivity (sBRS) and two factors are cardiorespiratory fitness (CRF) and arterial stiffness (AS). The aims of this study were to determine, firstly, whether there are differences in sBRS between young, normotensive AAM and CM, and secondly, to determine if CRF and AS are significant predictors of sBRS in young, normotensive AAM and CM. Methods: Twenty-three normotensive AAM and 36 CM were recruited from Southern Connecticut State University. Measures included anthropometric, sBRS (alpha-index), and CRF (maximal oxygen consumption [VO_2max]), as well as AS (carotid-femoral pulse wave velocity [Cf-PWV]). Independent t-tests were used to determine differences between groups and multiple regression analysis was used to determine how much of the variation in sBRS was explained by CRF and AS. Results: The sBRS was significantly lower in AAM (10.3 ± 3.8 ms/mmHg) vs. CM (13.3 ± 5.7 ms/ mmHg), P = 0.03. CRF and AS were not significant predictors of sBRS in AAM (P = 0.25) and CM (P = 0.30). There was no relationship between, sBRS, CRF and AS; CRF was significantly reduced in AAM vs. CM (45.1 ± 6.3 vs. 52.1 ± 7.5 mL·kg⁻¹·min⁻¹, P ≤ 0.001). Conclusions: Young normotensive AAM demonstrated significantly lower sBRS vs. CM, irrespective of having fair CRF and normal BP. CRF and AS are not significant predictors of sBRS in young, normotensive AAM and CM. The attenuation in sBRS in AAM did not result in AAM having higher BP versus CM. This finding underscores the need for more detailed examination of the role of sBRS in the etiology of HTN in AAM.

African-American Men, Spontaneous Baroreflex Sensitivity, Cardiorespiratory Fitness, Arterial Stiffness, Hypertension

Latchman, P. , Gates, G. , Thiel, R. , Axtell, R. , Zhu, W. , Morin-Viall, A. , Yue, T. , Yang, Q. , Gardner, K. and Meersman, R. (2019) Spontaneous Baroreflex Sensitivity in Normotensive African-American Men. Open Journal of Molecular and Integrative Physiology, 9, 1-10. doi: 10.4236/ojmip.2019.91001.