The influence of perceived discrimination on aortic hemodynamics in young Black adults

Abstract

Black adults experience the greatest prevalence of cardiovascular disease (CVD) risk factors and higher CVD mortality of any racial or ethnic group in the United States. The chronic stress from experiencing racial discrimination may exert a weathering effect that contributes to cardiovascular health inequities observed among Black adults. Prior evidence has suggested that Black adults experience greater aortic stiffness as compared with white adults. However, there is limited information regarding perceived racial discrimination and aortic hemodynamics in young adults. Purpose/Hypothesis: The purpose of this study was to determine whether perceived racial discrimination was associated with worse aortic hemodynamics in young Black adults. Methods: Black adults aged 18-25 (n=18, 44% female) volunteered to participate in this study. Participants arrived at the lab at 7:00AM in a fasted state. Following 30 minutes of rest, central pressure waveforms were derived from the radial artery waveform acquired via applanation tonometry and the use of the generalized transfer function. We report aortic augmentation pressure (AP, mmHg), augmentation index (AIx, %), augmentation index normalized to a heart rate of 75bpm (AIx75), round trip transit time (Tr, ms), and the subendocardial viability ratio (SEVR, %), also known as the Buckberg Index. Peak oxygen consumption (VO2 peak) was measured via Indirect calorimetry during a graded treadmill test. Participants completed a questionnaire that assessed personal-level and group-level discrimination. Partial correlations (Pearson’s r controlled for VO2 peak) were used to assess the association between perceived racial discrimination and aortic hemodynamics. Results: Perceived group-level discrimination was positively associated with AP (r = 0.571, p = 0.026), AIx (r = 0.580, p = 0.023), and AIx75 (r = 0.571, p = 0.026), signifying worse central hemodynamics that are indicative of increased left ventricular systolic load. However, perceived personal-level discrimination was not associated with aortic hemodynamics (ps>0.05). VO2peak was positively associated with Tr (r = 0.511, p = 0.043), signifying a later return of the reflected wave (i.e, better) to the heart to facilitate coronary perfusion during diastole. VO2 peak was also inversely associated with AIx75 (r = -0.657, p = 0.006). Conclusion: These preliminary data indicate that young Black adults who report higher group-level discrimination have an increased left ventricular systolic afterload in the aorta. Future studies investigating coping strategies or the effects of increased fitness to improve central hemodynamics in Black adults are warranted. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.