Racial Differences in Cerebral Hemodynamics during Aerobic Exercise

Authors

Ziba Taherzadeh, The University of Texas at ArlingtonFollow
Claire E. Kissel, The University of Texas at ArlingtonFollow
Taha Alhalimi, The University of Texas at ArlingtonFollow
Paul J. Fadel, The University of Texas at ArlingtonFollow

Abstract

Young healthy non-Hispanic Black (BL) adults have an attenuated increase in blood flow to working skeletal muscle during exercise compared to non-Hispanic white (WH) adults. Cerebral blood flow also increases during exercise; however, previous work has mainly included WH adults. There are no studies investigating potential differences in cerebral vascular responses to exercise in BL adults. PURPOSE: To compare middle cerebral artery velocity (MCAv) and cerebral vascular conductance index (CVCi) during exercise in BL adults to WH adults. We tested the hypothesis that BL adults have a blunted increase in MCAvmean and CVCi response during light and moderate intensity exercise compared to WH adults. METHODS: 12 young healthy adults, 6 BL (21 ± 4 years) and 6 WH (25 ± 5 years) were studied. Heart rate (ECG), brachial artery blood pressure (SunTech Tango), End tidal carbon dioxide(ETCO₂; Capnograph) and MCAvmean (transcranial Doppler) were measured at rest and during semi-recumbent cycling at light (25 Watts) and moderate intensity exercise. Moderate intensity exercise was defined as 60% heart rate reserve (HRR: {HR_max - HR_rest × 60%} + HR_rest), which is American College of Sports Medicine recommended level of physical activity intensity for adults. CVC_i was calculated as MCAvmean/mean arterial pressure and used as an index of vasodilation. RESULTS: At rest, there were no differences in MCAvmean (BL: 65.3 ± 11.5 cm/s vs. WH: 70.3 ± 11.1 cm/s; P = 0.46), ETCO₂ (BL: 48 ± 11 mmHg vs. WH: 46 ± 3 mmHg; P = 0.75) and CVCi (BL: 0.74 ± 0.16 cm.s^-1 /mmHg vs. WH: 0.75 ± 0.14 cm.s^-1 /mmHg; P = 0.88) between groups. Increases in MCAvmean, ETCO2 and CVCi from rest were not different between groups (all P > 0.05) during light intensity exercise. In addition, during 60%HRR exercise BL adults also had similar increases in MCAvmean (BL: 84.1 ± 13 cm/s vs. WH: 88.7 ± 22.4 cm/s; P = 0.67), ETCO₂ (BL: 48 ± 7 mmHg vs. WH: 52 ± 8 mmHg; P = 0.30) and CVCi (BL: 0.73 ± 0.17 cm.s^-1 /mmHg vs. WH: 0.80 ± 0.18 cm.s^-1 /mmHg; P = 0.50) compared to WH adults. CONCLUSION: These preliminary data suggest that the increase in cerebral blood velocity and CVCi changes during light and moderate intensity exercise are comparable between young BL and WH adults.

Recommended Citation

Taherzadeh, Ziba; Kissel, Claire E.; Alhalimi, Taha; and Fadel, Paul J. (2024) "Racial Differences in Cerebral Hemodynamics during Aerobic Exercise," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 16, Article 116.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss16/116