UBC Theses and Dissertations
Cardiac and vascular dynamics in persons of Aboriginal descent Foulds, Heather-Jean A
Introduction: Aboriginal populations currently experience greater rates of cardiovascular disease, than non-Aboriginals. Limited information regarding vascular and cardiac structure and function among this population are known, despite the close relationships of cardiac and vascular physiology to cardiovascular disease. Purposes: Theses investigations evaluate cardiac and vascular dynamics of Aboriginal Canadians, directly compare vascular measures between Aboriginal and European adults and evaluate the cardiac and vascular responses to exercise among Aboriginal and European adults. Methods: In the first investigation, 55 Aboriginal adults underwent a comprehensive vascular assessment. In Study 2, 10 Aboriginal adults underwent a resting echocardiographic evaluation. Study 3 compared the vascular status of 58 Aboriginal and 58 age- and sex-matched European adults. Vascular measures were assessed pre and post-exercise among 12 Aboriginal adults and 12 age- and sex matched European adults in Study 4. Pre and post-exercise cardiac assessments were performed on 12 Aboriginal and 12 age- and sex-matched European adults in Study 5. Results: In study 1, Aboriginal male and female adults (19-91 years) were found to have similar pulse wave velocity and intima-media thickness, with males having greater systolic blood pressure and small arterial compliance, and females having greater baroreceptor sensitivity. Study 2 identified Aboriginal males having larger left ventricular mass, dimensions, and volumes, while females had greater vascular resistance. In study 3, Aboriginal adults arterial compliance and baroreceptor sensitivity was identified as being more strongly associated with blood pressure compared to Europeans. Additionally, only European hypertension (blood pressure ≥140 mmHg systolic or ≥90 mmHg diastolic) rates were found to be associated with obesity (body mass index ≥30.0 kg•m-²). Study 4 identified European adults as having greater reductions in blood pressure following exercise, with a lack of change among Aboriginal adults. In study 5, Aboriginal and European adults were found to have similar cardiac functional responses to maximal aerobic exercise, including decreases in volumes and increases in arterial-ventricular coupling; however, only Aboriginal adults demonstrated decreases in volumes and compliance, and increases in elastance and stiffness following submaximal exercise. Conclusion: Differences in factors affecting blood pressure and blood pressure responses to exercise were identified between Aboriginal and European adults.
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Attribution-NonCommercial-NoDerivs 2.5 Canada