- Title
- ARTERIAL TONE IN BLACK WOMEN WITH PREECLAMPSIA FROM TRANSKEI REGION OF SOUTH AFRICA
- Creator
- AMBROSE VINCENT NAMUGOWA
- Date
- 2014
- Type
- PhD Manuscript
- Identifier
- http://hdl.handle.net/11260/2016
- Identifier
- vital:40802
- Identifier
- DOCTOR OF PHILOSOPHY (Ph.D) (In Health Sciences, Physiology)
- Description
- Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The mechanisms which mediate this heightened risk are poorly understood; it was long believed that pre-eclampsia was cured by delivery of the foetus. But it is now apparent that the risks of complications persist for some time after delivery. The aim of the study was to establish the presence and pattern of endothelial dysfunction during gestation and postpartum among women who develop preeclampsia in the Transkei region of South Africa. This was a two parts study: part one was a cross-sectional experimental study, which involved 85 women with established pre-eclampsia (PE) and 112 pregnant controls (PC); part two was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC). Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperaemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperaemia index (RHI) as a measure of endothelial function. In part one, the measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the pregnant control group.PE group compared with pregnant controls, PE had higher median pulse wave velocity [1.2 inter-quartile range (IQR) 1.08-1.35 MoM vs. 0.97, IQR 8.6-1.09 MoM; p=0.0000].In contrast, there were no ii significant differences between the two groups median of central augmentation index (1.0, IQR -0.4 -1.7 MoM vs. 0.9, IQR 0.69-1.36 MoM; p=0.765). RHI was higher in PE than controls (1.16, IQR 1-1.33 MoM vs. 1, IQR 0.9- 1.18 MoM; p=0.0000). Early-onset pre-eclampsia had higher median brachial blood pressure (87.5, IQR 79-101 vs. 82, IQR 65-88 mmHg; p=0.02), higher mean arterial pressure (110, IQR97-120 vs.101 IQR 88-110 mmHg; p=0.04) and higher central diastolic blood pressure (90, IQR 80-103 vs.84, IQR 67-90 mmHg; p=0.017) than the lateonset pre-eclampsia. Pulse wave velocity (carotid-femoral) was increased in pregnant women with preeclampsia during the third trimester. Reactive hyperaemia index, a measure of endothelial function, was higher in pregnant women with pre-eclampsia than pregnant controls. This suggests that regional (aortic) arterial stiffness is increased, but endothelial function, as assessed by ENDOPAT 2000 device, was not compromised in rural African women with pre-eclampsia. Pulse wave reflection, as assessed by augmentation index adjusted to heart rate of 75 beats/min, was increased in women who had early-onset pre-eclampsia more than those with late-onset pre-eclampsia. Brachial diastolic blood pressure was higher in early-onset pre-eclampsia which resulted in lower brachial pulse pressure than in the late-onset pre-eclampsia. Furthermore, the mean arterial pressure was higher in early-onset than late onset pre-eclampsia. This suggests that early onset pre-eclampsia is more severe condition than the late-onset pre-eclampsia. In part two, pulse wave velocity remained significantly higher in previously preeclamptic women than non-pregnant controls up to three months after delivery iii (p<0.05).Then it reduced to non significant values. Regional (aortic) arterial stiffness, though it persists for some time after delivery, it is transitory in previously pre-eclamptic women from the rural Africa setting. All blood pressure indices (central and brachial pressures), were increased in women who previously had pre-eclampsia as compared to non pregnant controls up to one year postpartum. Although pulse wave velocity and augmentation decrease to low values with time after delivery increased blood pressure is an indication of compromised arterial compliance in women with previously pre-eclampsia.
- Format
- Publisher
- Department of Physiology Faculty of Health Sciences
- Language
- English
- Rights
- Walter Sisulu University
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Namugowa PhD Thesis.pdf | 54 MB | Adobe Acrobat PDF | View Details Download |