title: Carotid characteristics of black South Africans with five-year sustained hypertension.
abstract: BACKGROUND
  An important feature of hypertension is a reduction in large artery distensibility, which may be due to structural and functional adaptations. Black populations are particularly prone to the development of hypertension. We therefore compared the carotid characteristics between five-year sustained hypertensive and normotensive black South Africans, and investigated how carotid characteristics relate to cardiometabolic risk factors, inflammation, endothelial activation and health behaviours.
  
  
  METHODS
  We included HIV-free black South Africans who were either consistently hypertensive (n = 351) or normotensive (n = 241) from 2005 to 2010. We assessed carotid characteristics, including intima-media thickness (IMT), distensibility and lumen diameter with B-mode ultrasound, and calculated Young's elastic modulus, cross-sectional wall area and beta-stiffness index. We measured the carotid dorsalis pedis pulse-wave velocity, brachial and central systolic blood pressure (cSBP) and determined metabolic, inflammatory and endothelial activation markers from blood samples. Health behaviours were reported in questionnaires.
  
  
  RESULTS
  The hypertensive group presented with higher brachial and central blood pressure, thicker IMT and stiffer carotid arteries (all p < 0.001). However, after adjustment for cSBP but not mean arterial pressure (MAP), all significant differences in carotid characteristics were lost. The carotid thickness measurements did not differ after adjustment for MAP. After adjustment, metabolic, inflammatory and endothelial activation markers did not differ between the two groups.
  
  
  CONCLUSIONS
  Our results suggest that besides structural changes, functional adaptations are also involved in deterioration of the carotid wall characteristics of hypertensive black South Africans. These results highlight the importance of proper hypertension control in Africa.
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
authors.forename: Melissa
authors.initials: M
authors.lastname: Maritz
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa. Email: carla.fourie@nwu.ac.za.
authors.forename: Carla M
authors.initials: CM
authors.lastname: Fourie
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: van Rooyen
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
authors.forename: Hugo W
authors.initials: HW
authors.lastname: Huisman
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.
authors.forename: Aletta E
authors.initials: AE
authors.lastname: Schutte
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D044383:Black People / Q000523:psychology; D001794:Blood Pressure; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000097:blood / Q000000981:diagnostic imaging / Q000208:ethnology / Q000503:physiopathology*; D059168:Carotid Intima-Media Thickness; D016022:Case-Control Studies; D055119:Elastic Modulus; D005260:Female; D015438:Health Behavior / Q000208:ethnology; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology* / Q000523:psychology; D018836:Inflammation Mediators / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D013019:South Africa / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013997:Time Factors; D059289:Vascular Stiffness
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D008055:Lipids