The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates

dc.contributor.advisorRayner, Brian Lindsay
dc.contributor.authorSimba, Kudakwashe
dc.date.accessioned2020-02-24T11:13:11Z
dc.date.available2020-02-24T11:13:11Z
dc.date.issued2019
dc.date.updated2020-02-24T08:11:55Z
dc.description.abstractBACKGROUND Vascular calcification is a major risk factor for cardiovascular morbidity and mortality in patients with end stage renal disease (ESRD). In Western countries, Blacks with ESRD appear to have lesser degrees of vascular calcification compared to non-Blacks. However, there is no published data on the association of ethnic differences in vascular calcification and survival in ESRD from Sub-Saharan Africa. METHODS This study assessed the 5-year change in vascular calcification and mortality in a previously published cohort of patients with ESRD. Vascular calcification was assessed by abdominal aortic calcification score (lateral abdominal radiograph) and vascular stiffness by pulse wave velocity. RESULTS Sixty-six of the original 74 participants, studied a baseline, were identified. The median age was 46.6 years (37.6-59.2) and 57.6% were women. Abdominal aortic calcification showed no progression among Blacks [baseline range 0-5, follow up range 0-8 (p=1.00)], but a nonsignificant trend to progression among non-Blacks [baseline range 0-19, follow up range 0-22 (p=0.066)]. Black participants did not display a survival advantage (p=0.870). Overall, sepsis was the most common cause of mortality (64% of those with an identifiable cause of death). Non-Blacks had higher parathyroidectomy rates than Blacks with 9/30 cases compared to 2/36 (p=0.036). After adjustment for parathyroidectomy at follow up, the odds ratio of having abdominal vascular calcification score of ≥1 amongst non-Blacks was 8.6-fold greater compared to Blacks (p= 0.03). Central aortic systolic pressures (CASP) and pulse wave velocities (PWV) were higher in the study population than age matched normative values. At follow up, a positive correlation (r=0.3) was observed between PWV and abdominal aortic calcification (p=0.04). Elevated baseline coronary artery calcification score and FGF-23 level at baseline were not associated with a difference in mortality. CONCLUSION There was no significant progression in vascular calcification among Blacks. After adjusting for increased parathyroidectomy rates, there was a greater progression of vascular calcification amongst non-Blacks compared to Blacks highlighting possible ethnic differences in calcium phosphate metabolism in patients with ESRD. The lack of vascular calcification progression in Blacks was not however associated with improved survival, but the sample size was small.
dc.identifier.apacitationSimba, K. (2019). <i>The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates</i>. (). ,Faculty of Health Sciences ,Department of Medicine. Retrieved from http://hdl.handle.net/11427/31257en_ZA
dc.identifier.chicagocitationSimba, Kudakwashe. <i>"The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates."</i> ., ,Faculty of Health Sciences ,Department of Medicine, 2019. http://hdl.handle.net/11427/31257en_ZA
dc.identifier.citationSimba, K. 2019. The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Simba, Kudakwashe AB - BACKGROUND Vascular calcification is a major risk factor for cardiovascular morbidity and mortality in patients with end stage renal disease (ESRD). In Western countries, Blacks with ESRD appear to have lesser degrees of vascular calcification compared to non-Blacks. However, there is no published data on the association of ethnic differences in vascular calcification and survival in ESRD from Sub-Saharan Africa. METHODS This study assessed the 5-year change in vascular calcification and mortality in a previously published cohort of patients with ESRD. Vascular calcification was assessed by abdominal aortic calcification score (lateral abdominal radiograph) and vascular stiffness by pulse wave velocity. RESULTS Sixty-six of the original 74 participants, studied a baseline, were identified. The median age was 46.6 years (37.6-59.2) and 57.6% were women. Abdominal aortic calcification showed no progression among Blacks [baseline range 0-5, follow up range 0-8 (p=1.00)], but a nonsignificant trend to progression among non-Blacks [baseline range 0-19, follow up range 0-22 (p=0.066)]. Black participants did not display a survival advantage (p=0.870). Overall, sepsis was the most common cause of mortality (64% of those with an identifiable cause of death). Non-Blacks had higher parathyroidectomy rates than Blacks with 9/30 cases compared to 2/36 (p=0.036). After adjustment for parathyroidectomy at follow up, the odds ratio of having abdominal vascular calcification score of ≥1 amongst non-Blacks was 8.6-fold greater compared to Blacks (p= 0.03). Central aortic systolic pressures (CASP) and pulse wave velocities (PWV) were higher in the study population than age matched normative values. At follow up, a positive correlation (r=0.3) was observed between PWV and abdominal aortic calcification (p=0.04). Elevated baseline coronary artery calcification score and FGF-23 level at baseline were not associated with a difference in mortality. CONCLUSION There was no significant progression in vascular calcification among Blacks. After adjusting for increased parathyroidectomy rates, there was a greater progression of vascular calcification amongst non-Blacks compared to Blacks highlighting possible ethnic differences in calcium phosphate metabolism in patients with ESRD. The lack of vascular calcification progression in Blacks was not however associated with improved survival, but the sample size was small. DA - 2019 DB - OpenUCT DP - University of Cape Town KW - Chronic kidney disease KW - dialysis KW - vascular calcification KW - vascular stiffness KW - pulse wave velocity KW - FGF- 23 LK - https://open.uct.ac.za PY - 2019 T1 - The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates TI - The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates UR - http://hdl.handle.net/11427/31257 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/31257
dc.identifier.vancouvercitationSimba K. The impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates. []. ,Faculty of Health Sciences ,Department of Medicine, 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/31257en_ZA
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Medicine
dc.publisher.facultyFaculty of Health Sciences
dc.subjectChronic kidney disease
dc.subjectdialysis
dc.subjectvascular calcification
dc.subjectvascular stiffness
dc.subjectpulse wave velocity
dc.subjectFGF- 23
dc.titleThe impact of vascular calcification among dialysis dependent South African CKD patients. A five year follow up study. Cardiovascular mortality and morbidity, ethnic variation and hemodynamic correlates
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMMed
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