Distinct Contribution of Systemic Blood Flow to Hypertension in an African Population Across the Adult Lifespan. Issue 2 (August 2020)

• Record Type: Journal Article
• Authors: Woodiwiss, Angela J.; Mmopi, Keneilwe N.; Peterson, Vernice; Libhaber, Carlos; Bello, Hamza; Masiu, Mohlabani; Fernandes, Daniel Da Silva; Tade, Grace; Mthembu, Nonhlanhla; Peters, Ferande; Sareli, Pinhas; Norton, Gavin R.
• Is Part Of: Hypertension. Volume 76:Issue 2(2020)
• Publication Date: 2020-08
• Subjects: aldosterone -- blood pressure -- compliance -- stroke volume -- vascular resistance; Hypertension -- Periodicals; Hypertension -- Treatment -- Periodicals; 616.132005
• DOI: 10.1161/HYPERTENSIONAHA.120.14925
• Languages: English
• ISSNs: 0194-911X

Abstract

Abstract : Although hypertension in groups of African ancestry is volume-dependent, the relative impact of systemic flow (stroke volume, peak aortic flow [Q]) versus vascular mechanisms (systemic vascular resistance, aortic characteristic impedance [Zc], total arterial compliance) components of arterial load has not been evaluated across the adult age range. In participants of African ancestry (n=824, age=16–99 years, 68.3% female), using central arterial pressure and aortic velocity and diameter measurements in the outflow tract, we determined the hemodynamic correlates of age-related increases in blood pressure. Strong independent positive relations between age and stroke volume or peak aortic Q were noted ( P <0.0001), effects associated with ventricular end diastolic volume and aldosterone-to-renin ratios. Age-related increases in mean arterial pressure were associated with stroke volume and not systemic vascular resistance. Although age-Q relations began from early adulthood, initially an inverse association between age and aortic Zc ( P <0.0001) driven by increments in aortic root diameter ( P <0.0001) prevented an enhanced systolic blood pressure and pulse pressure. When Zc began to positively relate to age ( P <0.0001), age-Q relations translated into increases in forward wave pressures and hence systolic blood pressure and pulse pressure. Age relations with pulse pressure were as strongly determined by Q as by Zc or total arterial compliance (0.027±0.001 versus 0.028±0.001 and 0.032±0.003 mm Hg per yearly increase in pulse pressure produced by Q, Zc, and total arterial compliance; P <0.0001). Uncontrolled hypertension (confirmed with 24-hour blood pressure) was determined more by Q, Zc, and total arterial compliance than by increases in systemic vascular resistance ( P <0.0005 for comparison). In conclusion, relationships between age and systemic blood flow contribute markedly to hypertension in groups of African origins. Abstract : Supplemental Digital Content is available in the text.