Ethnic differences in the hemodynamic mechanisms of ambulatory blood pressure regulation

Abstract Background African Americans typically exhibit greater systemic vascular resistance (SVR) than do white individuals in response to laboratory challenges that raise blood pressure (BP). However, ethnic differences in ambulatory blood pressure (ABP) regulation have not been examined. Methods We monitored ABP in a sample of 10 African American and 10 white men and women. Ambulatory cardiac impedance monitoring was used to assess cardiac output and SVR concurrently with each ABP reading. Results We found that SVR was a significant predictor of daily ABP variations in African Americans (P< .01) but not in whites. Conclusion For African Americans, SVR may play a more prominent role than for whites in the regulation of ABP during routine daily activities.