Motivation Hypertension is a pertinent health problem for urban black African men (hereafter referred to as African). Sympathetic hyperactivity and a dominant α-adrenergic response pattern have both been implicated as contributing factors to their poor cardiovascular health. In addition to the deleterious effect of neurogenic hypertension on target organs, sympathetic hyperactivity may promote the accelerated progression of left ventricular hypertrophy and structural vascular disease. Aim The overarching aim of this study is to scrutinize autonomic control of the cardiovascular system in a cohort of urban African and Caucasian men during a mental challenge. Associations were investigated between potential sympatho-vagal imbalance, blood pressure and target organ damage markers to determine cardiovascular risk in ethnic male groups. Methodology The SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study involved the participation of 200 male teachers (99 African and 101 Caucasian) in the Kenneth Kaunda Education District of the North-West Province, South Africa. Of the participant group, HIV-infected (13 African) and clinically confirmed diabetics (1 Caucasian and 6 African men) were excluded from further analyses. Stratification was based on ethnicity and further as indicated through statistical interaction effects. Cardiovascular and autonomic responses were assessed during rest and on stressor exposure (cold pressor test and Stroop colour-word conflict test). Autonomic measures included baroreceptor sensitivity (BRS), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and nitric oxide metabolite (NOx) levels. Cardiovascular variables consisted of blood pressure, cardiac output, stroke volume, total peripheral resistance, heart rate, arterial compliance and ST-segment from the 12-lead electrocardiogram. Markers of target organ damage included the Cornell product (indication of left ventricular hypertrophy) and carotid intima-media thickness as indication of structural vascular disease. Means and proportions were compared by means of standard t-test and Chi-square test, respectively. Significant differences of mean cardiovascular and autonomic measures between ethnic male groups were also determined through analysis of covariance. Uni- and multivariate regression analyses were employed to demonstrate associations between target organ damage, cardiovascular and autonomic markers. Results and conclusion of each manuscript To assess autonomic nervous system and cardiovascular function as well as target organ damage, we clearly focussed on responses where our participants were challenged. Markers of autonomic responses assessed were baroreceptor sensitivity, 3-methoxy-4-hydroxyphenylglycol and nitric oxide metabolites.  The first manuscript (Chapter 2) focused on left ventricular hypertrophy as marker of target organ damage, blood pressure and baroreceptor sensitivity as marker of autonomic function. The objective was to determine whether BRS was significantly lower in African men than in the Caucasian men. Furthermore, the possible association between attenuation of BRS and increased levels of ambulatory blood pressure as well as left ventricular hypertrophy was investigated in these population groups. Results revealed that the African men had significantly lower BRS stress responses. This attenuated BRS profile was coupled with dominant α-adrenergic response patterns, which was associated with an elevation of ambulatory blood pressure. BRS attenuation (rest and stress response) was not associated with left ventricular hypertrophy. It was concluded that lower BRS, especially during stress, may pose a significant health threat for urban African men regarding the development or promotion of α-adrenergic-driven hypertension and higher cardiovascular disease risk.  The aim of the second sub-study (Chapter 3) was to investigate possible associations between structural vascular disease (carotid intima-media thickness as marker), autonomic function (MHPG as marker) and nocturnal blood pressure in the African and Caucasian men. Results showed a higher prevalence of nocturnal hypertension in the African men, with night-time blood pressure significantly higher compared to the Caucasian men. In the African and Caucasian men, carotid intima-media thickness was linearly predicted by nocturnal systolic and diastolic blood pressure respectively. In conclusion, no associations were demonstrated between MHPG and carotid intimamedia thickness or between MHPG and nocturnal blood pressure. Elevated nocturnal blood pressure evidently seems to promote structural vascular disease in this cohort of urban African and Caucasian men.  The aim of the third manuscript presented in Chapter 4, was to investigate bioavailability of NO during mental challenge (autonomic function marker) and the possible association with structural vascular disease (carotid intima-media thickness as marker). In the African men, an attenuated NOx response was demonstrated to the Stroop colour-word conflict test. After stratification into high and low NOx response groups, in the African men with a low NOx response enhanced α-adrenergic with significant STsegment depression responses was demonstrated indicating reduced myocardial oxygen supply during mental stressor exposure. Only in the African men, a ST-segment depression was significantly associated with structural vascular disease. It was concluded that the African men demonstrated a vulnerable cardiovascular profile. In this cohort of African men, the significant association between structural vascular disease and myocardial ischemia may particularly indicate a possible higher risk for future cardiovascular events. General conclusion Through the assessment of autonomic and cardiovascular responses a possible higher cardiovascular risk was demonstrated in the African men. In this cohort sympathetic hyperactivity was evident, coupled with dominant vascular response patterns and reduced myocardial oxygen supply during mental stress exposure. Based on these findings, this population group’s risk for accelerated target organ damage, as well as for future cardiovascular events, appear significantly higher than those of the Caucasian male cohort. / Thesis (PhD (Physiology))--North-West University, Potchefstroom Campus, 2013.

Motivation Hypertension is a pertinent health problem for urban black African men (hereafter referred to as African). Sympathetic hyperactivity and a dominant α-adrenergic response pattern have both been implicated as contributing factors to their poor cardiovascular health. In addition to the deleterious effect of neurogenic hypertension on target organs, sympathetic hyperactivity may promote the accelerated progression of left ventricular hypertrophy and structural vascular disease. Aim The overarching aim of this study is to scrutinize autonomic control of the cardiovascular system in a cohort of urban African and Caucasian men during a mental challenge. Associations were investigated between potential sympatho-vagal imbalance, blood pressure and target organ damage markers to determine cardiovascular risk in ethnic male groups. Methodology The SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study involved the participation of 200 male teachers (99 African and 101 Caucasian) in the Kenneth Kaunda Education District of the North-West Province, South Africa. Of the participant group, HIV-infected (13 African) and clinically confirmed diabetics (1 Caucasian and 6 African men) were excluded from further analyses. Stratification was based on ethnicity and further as indicated through statistical interaction effects. Cardiovascular and autonomic responses were assessed during rest and on stressor exposure (cold pressor test and Stroop colour-word conflict test). Autonomic measures included baroreceptor sensitivity (BRS), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and nitric oxide metabolite (NOx) levels. Cardiovascular variables consisted of blood pressure, cardiac output, stroke volume, total peripheral resistance, heart rate, arterial compliance and ST-segment from the 12-lead electrocardiogram. Markers of target organ damage included the Cornell product (indication of left ventricular hypertrophy) and carotid intima-media thickness as indication of structural vascular disease. Means and proportions were compared by means of standard t-test and Chi-square test, respectively. Significant differences of mean cardiovascular and autonomic measures between ethnic male groups were also determined through analysis of covariance. Uni- and multivariate regression analyses were employed to demonstrate associations between target organ damage, cardiovascular and autonomic markers. Results and conclusion of each manuscript To assess autonomic nervous system and cardiovascular function as well as target organ damage, we clearly focussed on responses where our participants were challenged. Markers of autonomic responses assessed were baroreceptor sensitivity, 3-methoxy-4-hydroxyphenylglycol and nitric oxide metabolites.  The first manuscript (Chapter 2) focused on left ventricular hypertrophy as marker of target organ damage, blood pressure and baroreceptor sensitivity as marker of autonomic function. The objective was to determine whether BRS was significantly lower in African men than in the Caucasian men. Furthermore, the possible association between attenuation of BRS and increased levels of ambulatory blood pressure as well as left ventricular hypertrophy was investigated in these population groups. Results revealed that the African men had significantly lower BRS stress responses. This attenuated BRS profile was coupled with dominant α-adrenergic response patterns, which was associated with an elevation of ambulatory blood pressure. BRS attenuation (rest and stress response) was not associated with left ventricular hypertrophy. It was concluded that lower BRS, especially during stress, may pose a significant health threat for urban African men regarding the development or promotion of α-adrenergic-driven hypertension and higher cardiovascular disease risk.  The aim of the second sub-study (Chapter 3) was to investigate possible associations between structural vascular disease (carotid intima-media thickness as marker), autonomic function (MHPG as marker) and nocturnal blood pressure in the African and Caucasian men. Results showed a higher prevalence of nocturnal hypertension in the African men, with night-time blood pressure significantly higher compared to the Caucasian men. In the African and Caucasian men, carotid intima-media thickness was linearly predicted by nocturnal systolic and diastolic blood pressure respectively. In conclusion, no associations were demonstrated between MHPG and carotid intimamedia thickness or between MHPG and nocturnal blood pressure. Elevated nocturnal blood pressure evidently seems to promote structural vascular disease in this cohort of urban African and Caucasian men.  The aim of the third manuscript presented in Chapter 4, was to investigate bioavailability of NO during mental challenge (autonomic function marker) and the possible association with structural vascular disease (carotid intima-media thickness as marker). In the African men, an attenuated NOx response was demonstrated to the Stroop colour-word conflict test. After stratification into high and low NOx response groups, in the African men with a low NOx response enhanced α-adrenergic with significant STsegment depression responses was demonstrated indicating reduced myocardial oxygen supply during mental stressor exposure. Only in the African men, a ST-segment depression was significantly associated with structural vascular disease. It was concluded that the African men demonstrated a vulnerable cardiovascular profile. In this cohort of African men, the significant association between structural vascular disease and myocardial ischemia may particularly indicate a possible higher risk for future cardiovascular events. General conclusion Through the assessment of autonomic and cardiovascular responses a possible higher cardiovascular risk was demonstrated in the African men. In this cohort sympathetic hyperactivity was evident, coupled with dominant vascular response patterns and reduced myocardial oxygen supply during mental stress exposure. Based on these findings, this population group’s risk for accelerated target organ damage, as well as for future cardiovascular events, appear significantly higher than those of the Caucasian male cohort. / Thesis (PhD (Physiology))--North-West University, Potchefstroom Campus, 2013.

Objectives: The aim of this study was to determine associations between physical activity (PA), blood pressure (BP) and renin in urban black Africans. Methods: The study sample included 137 urban African males (N=68) and females (N=69) (aged 41.53 ± 8.13 and 44.16 ± 7.37 years, respectively), from the North West Province, South Africa. Anthropometric measurements, ambulatory blood pressure and energy expenditure were determined. Actical® accelerometers were used to determine energy expenditure (METS) over a 24 hour period. Fasting blood samples were used to determine fasting blood glucose, serum cotinine (COT), gamma–glutamyl transferase (GGT) and plasma renin. Results: A greater percentage (64%) of African males were hypertensive compared to African females (33.33%). SBP (p<0.001) and DBP (p<0.001) were significantly higher in males than females. Female subjects were more obese (32.00±7.75 kg/m2) whereas males demonstrated an overweight status (27.28±5.86kg/m2). Male subjects displayed overall higher lifestyle risks (BP, smoking, alcohol consumption, HIV–status) than females. Multivariate regression analyses demonstrated an inverse relationship between BP and renin in both males and females, but no associations existed between renin and physical inactivity. Conclusion: PA appeared not to buffer elevated blood pressure in this specific African sample, as no significant associations supported this hypothesis. The results confirm that black Africans display lower renin levels associated with elevated blood pressure. Furthermore, low renin and physical inactivity was not related to indicate elevated BP through elevated SNS activity. / Thesis (M.Sc. (Biokinetics))--North-West University, Potchefstroom Campus, 2012.

Objectives: The aim of this study was to determine associations between physical activity (PA), blood pressure (BP) and renin in urban black Africans. Methods: The study sample included 137 urban African males (N=68) and females (N=69) (aged 41.53 ± 8.13 and 44.16 ± 7.37 years, respectively), from the North West Province, South Africa. Anthropometric measurements, ambulatory blood pressure and energy expenditure were determined. Actical® accelerometers were used to determine energy expenditure (METS) over a 24 hour period. Fasting blood samples were used to determine fasting blood glucose, serum cotinine (COT), gamma–glutamyl transferase (GGT) and plasma renin. Results: A greater percentage (64%) of African males were hypertensive compared to African females (33.33%). SBP (p<0.001) and DBP (p<0.001) were significantly higher in males than females. Female subjects were more obese (32.00±7.75 kg/m2) whereas males demonstrated an overweight status (27.28±5.86kg/m2). Male subjects displayed overall higher lifestyle risks (BP, smoking, alcohol consumption, HIV–status) than females. Multivariate regression analyses demonstrated an inverse relationship between BP and renin in both males and females, but no associations existed between renin and physical inactivity. Conclusion: PA appeared not to buffer elevated blood pressure in this specific African sample, as no significant associations supported this hypothesis. The results confirm that black Africans display lower renin levels associated with elevated blood pressure. Furthermore, low renin and physical inactivity was not related to indicate elevated BP through elevated SNS activity. / Thesis (M.Sc. (Biokinetics))--North-West University, Potchefstroom Campus, 2012.

BACKGROUND Cardiovascular disease (CVD) is a major health problem worldwide. In South Africa, the prevalence of cardiovascular disease (CVD) is often underestimated. The prevalence of CVD is very high, especially in urban areas, where two thirds of Africans present with multiple risk factors for CVD. The surge in CVD seems largely caused by modifiable risk factors. Although several studies have been conducted on the high prevalence and burden of CVD, there is limited research investigating possible relationships between CV risk factors and CVD knowledge. In order to address the burden of CVD as a public health issue, it is necessary to determine the level of CVD knowledge to bridge the possible knowledge gap in the control and primary prevention of CVD. It is therefore important to get a clear understanding of the relationship between CV risk factors and knowledge of CVD to contribute to the development and implementation of primary prevention programmes to reduce the prevalence of CVD. The findings from the study may be useful in designing community based health promotion programmes to prevent and control CVD within primary health care settings. A clear and comprehensive understanding of how risk factors contribute to the development of the CVD may enable individuals to identify their risk factors, but also to take action to reduce their risk for developing CVD. AIM This study aimed to determine the relationship between CV risk factors and knowledge of CVD in a group of African men. METHODOLOGY This study is quantitative in nature and followed a descriptive correlational design to describe the relationship between CV risk factors and knowledge of CVD. The study included 118 African men employed at the Vaalharts Water Scheme, North-West Province, South Africa. For the purpose of the study, data was collected by means of questionnaires and individual health screening. Participants completed a general health questionnaire, as well as a Heart Disease Knowledge Questionnaire. Individual health screening included anthropometric measurements (height, weight, waist circumference and body mass index), blood pressure (BP), rapid testing of blood glucose and cholesterol. By using Pearson correlations we determined whether CVD knowledge scores relate to individual CV risk factors. RESULTS The mean CV knowledge score was 75%, with an acceptable Cronbach’s alpha of 0.64 (CA=0.64). One third of the group displayed moderate to high CV risk profiles. Participants had a mean BP of 146/92 mmHg, which falls in the hypertensive range of the European guidelines. Their fasting blood glucose levels of 5.8 ± 2.0mmol/L were higher than the normal cut-off of 5.6mmol/L. Their mean body mass index was 25.9 ± 5.9 kg/m2. Overall, we observed a lack of association between CV risk factors and CVD knowledge. Only one borderline significant association existed between triglycerides and CVD knowledge (r=0.167; p=0.071). CONCLUSIONS Despite African men having increased CV risk and a relatively good knowledge of CVD risk factors, there seems to be a disconnect between their CV risk and CVD knowledge. Furthermore, in this group of African men, this knowledge does not appear to translate to changes in their own perceived severity of risk factors. Our results suggest that a good CVD knowledge does not appear to influence changes in CV risk factor levels. / MCur, North-West University, Potchefstroom Campus, 2015

BACKGROUND Cardiovascular disease (CVD) is a major health problem worldwide. In South Africa, the prevalence of cardiovascular disease (CVD) is often underestimated. The prevalence of CVD is very high, especially in urban areas, where two thirds of Africans present with multiple risk factors for CVD. The surge in CVD seems largely caused by modifiable risk factors. Although several studies have been conducted on the high prevalence and burden of CVD, there is limited research investigating possible relationships between CV risk factors and CVD knowledge. In order to address the burden of CVD as a public health issue, it is necessary to determine the level of CVD knowledge to bridge the possible knowledge gap in the control and primary prevention of CVD. It is therefore important to get a clear understanding of the relationship between CV risk factors and knowledge of CVD to contribute to the development and implementation of primary prevention programmes to reduce the prevalence of CVD. The findings from the study may be useful in designing community based health promotion programmes to prevent and control CVD within primary health care settings. A clear and comprehensive understanding of how risk factors contribute to the development of the CVD may enable individuals to identify their risk factors, but also to take action to reduce their risk for developing CVD. AIM This study aimed to determine the relationship between CV risk factors and knowledge of CVD in a group of African men. METHODOLOGY This study is quantitative in nature and followed a descriptive correlational design to describe the relationship between CV risk factors and knowledge of CVD. The study included 118 African men employed at the Vaalharts Water Scheme, North-West Province, South Africa. For the purpose of the study, data was collected by means of questionnaires and individual health screening. Participants completed a general health questionnaire, as well as a Heart Disease Knowledge Questionnaire. Individual health screening included anthropometric measurements (height, weight, waist circumference and body mass index), blood pressure (BP), rapid testing of blood glucose and cholesterol. By using Pearson correlations we determined whether CVD knowledge scores relate to individual CV risk factors. RESULTS The mean CV knowledge score was 75%, with an acceptable Cronbach’s alpha of 0.64 (CA=0.64). One third of the group displayed moderate to high CV risk profiles. Participants had a mean BP of 146/92 mmHg, which falls in the hypertensive range of the European guidelines. Their fasting blood glucose levels of 5.8 ± 2.0mmol/L were higher than the normal cut-off of 5.6mmol/L. Their mean body mass index was 25.9 ± 5.9 kg/m2. Overall, we observed a lack of association between CV risk factors and CVD knowledge. Only one borderline significant association existed between triglycerides and CVD knowledge (r=0.167; p=0.071). CONCLUSIONS Despite African men having increased CV risk and a relatively good knowledge of CVD risk factors, there seems to be a disconnect between their CV risk and CVD knowledge. Furthermore, in this group of African men, this knowledge does not appear to translate to changes in their own perceived severity of risk factors. Our results suggest that a good CVD knowledge does not appear to influence changes in CV risk factor levels. / MCur, North-West University, Potchefstroom Campus, 2015

Motivation: C-reactive protein (hs-CRP) and other risk factors such as cortisol and obesity in the diagnosis of cardiovascular dysfunction (CVD) in African and Caucasian women has become increasingly imperative when one considers the escalation of hypertension among these groups. Recent studies have explored some aspects of these risk factors and the roles that they play within hypertension and possible future risk for cardiovascular disease. Hs-CRP has been associated with the increased prevalence of hypertension and obesity. Cortisol per se has also been linked with the development of both hypertension and the hypothalamic-pituitary adrenal cortex (HPA) response. Nevertheless, the exact mechanism remains rather uncertain due to conflicting outcomes of research within different ethnic groups. Several recent investigations have, however, linked hypocortisolism with both urbanisation and a subsequent increased likelihood of hypertension within African women as they have presented increased vascular blood pressure responses. Conversely, Caucasian women have displayed an increased central cardiac reactivity. The lack of data regarding the relationship between the above-mentioned parameters within both African and Caucasian women serves as the motivation for conducting this study. Objective: To investigate hs-CRP, cortisol and hypertension as contributors to the increased likelihood of cardiovascular dysfunction in both African and Caucasian women within South Africa. hs-CRP use this through whole document please Methodology: The manuscript presented in Chapter 2 has been compiled using data obtained from the POWIRS (Profiles of Obese Women with Insulin Resistance Syndrome) study. Apparently healthy African (N=102) and Caucasian (N=115) women, matched for age and body mass index, were recruited from the North-West Province of South Africa for participation within this study. Subjects were divided into normotensive (NT) and hypertensive (HT) groups according to the mean resting cardiovascular values that were taken using a Finometer device. High-sensitivity C-reactive protein (hs-CRP) and cortisol blood serum values were determined by immunochemistry and ELISA analyses. Significant differences within each ethnic group and between each of the groups (NT and HT) were determined by analysis of covariance (ANCOVA), for anthropometric, cardiovascular, hs-CRP and cortisol variables, while adjusting for cardiovascular covariates (age, smoking and alcohol consumption). Partial correlations analyses were used to examine the relationship between hs-CRP, cortisol, anthropometric and cardiovascular parameters adjusting for cardiovascular covariates. Logistic regression analyses was used within each ethnic group to determine the relationship between anthropometric, cardiovascular, hs-CRP and cortisol as independent variables and hypertension as dependent variable. This study was approved by the Ethics Committee of the North-West University and all subjects gave informed consent in writing. For a more detailed description of the subjects, study design and analytical procedures please refer to the Materials and Methods section within Chapter 2 of this dissertation. Results and Conclusion: Both ethnic groups presented higher hs-CRP and lower cortisol levels compared to normal values. Lower waist circumference (WC) and cortisol as well as higher blood pressure (BP) and vascular values were evident in Africans compared to Caucasians. Both HT ethnic groups were older and more visceral obese compared to their NT counterparts. HT Caucasians indicated higher central adrenergic responses whilst HT Africans showed vascular adrenergicresponses. Only NT Africans had lower cortisol values than NT Caucasians but the Africans (NT and HT) responded with higher diastolic blood pressure responses compared to their Caucasian counterparts. Moreover, hs-CRP within African women significantly correlated with all BP and obesity variables whilst hs-CRP only associated with stroke volume (SV) and compliance (Cw) within HT Caucasian women. Cortisol in both ethnic groups was strongly associated with vascular BP responses. Only BP contributed to the higher prevalence of HT in both ethnic groups. In conclusion, these results suggest the possible diverse roles of HPA axis dysregulation associated with higher inflammatory responses. This happens in conjunction with cardiac and vascular responses within more obese Caucasian and especially African women, respectively. / MSc (Physiology), North-West University, Potchefstroom Campus, 2009

Motivation: C-reactive protein (hs-CRP) and other risk factors such as cortisol and obesity in the diagnosis of cardiovascular dysfunction (CVD) in African and Caucasian women has become increasingly imperative when one considers the escalation of hypertension among these groups. Recent studies have explored some aspects of these risk factors and the roles that they play within hypertension and possible future risk for cardiovascular disease. Hs-CRP has been associated with the increased prevalence of hypertension and obesity. Cortisol per se has also been linked with the development of both hypertension and the hypothalamic-pituitary adrenal cortex (HPA) response. Nevertheless, the exact mechanism remains rather uncertain due to conflicting outcomes of research within different ethnic groups. Several recent investigations have, however, linked hypocortisolism with both urbanisation and a subsequent increased likelihood of hypertension within African women as they have presented increased vascular blood pressure responses. Conversely, Caucasian women have displayed an increased central cardiac reactivity. The lack of data regarding the relationship between the above-mentioned parameters within both African and Caucasian women serves as the motivation for conducting this study. Objective: To investigate hs-CRP, cortisol and hypertension as contributors to the increased likelihood of cardiovascular dysfunction in both African and Caucasian women within South Africa. hs-CRP use this through whole document please Methodology: The manuscript presented in Chapter 2 has been compiled using data obtained from the POWIRS (Profiles of Obese Women with Insulin Resistance Syndrome) study. Apparently healthy African (N=102) and Caucasian (N=115) women, matched for age and body mass index, were recruited from the North-West Province of South Africa for participation within this study. Subjects were divided into normotensive (NT) and hypertensive (HT) groups according to the mean resting cardiovascular values that were taken using a Finometer device. High-sensitivity C-reactive protein (hs-CRP) and cortisol blood serum values were determined by immunochemistry and ELISA analyses. Significant differences within each ethnic group and between each of the groups (NT and HT) were determined by analysis of covariance (ANCOVA), for anthropometric, cardiovascular, hs-CRP and cortisol variables, while adjusting for cardiovascular covariates (age, smoking and alcohol consumption). Partial correlations analyses were used to examine the relationship between hs-CRP, cortisol, anthropometric and cardiovascular parameters adjusting for cardiovascular covariates. Logistic regression analyses was used within each ethnic group to determine the relationship between anthropometric, cardiovascular, hs-CRP and cortisol as independent variables and hypertension as dependent variable. This study was approved by the Ethics Committee of the North-West University and all subjects gave informed consent in writing. For a more detailed description of the subjects, study design and analytical procedures please refer to the Materials and Methods section within Chapter 2 of this dissertation. Results and Conclusion: Both ethnic groups presented higher hs-CRP and lower cortisol levels compared to normal values. Lower waist circumference (WC) and cortisol as well as higher blood pressure (BP) and vascular values were evident in Africans compared to Caucasians. Both HT ethnic groups were older and more visceral obese compared to their NT counterparts. HT Caucasians indicated higher central adrenergic responses whilst HT Africans showed vascular adrenergicresponses. Only NT Africans had lower cortisol values than NT Caucasians but the Africans (NT and HT) responded with higher diastolic blood pressure responses compared to their Caucasian counterparts. Moreover, hs-CRP within African women significantly correlated with all BP and obesity variables whilst hs-CRP only associated with stroke volume (SV) and compliance (Cw) within HT Caucasian women. Cortisol in both ethnic groups was strongly associated with vascular BP responses. Only BP contributed to the higher prevalence of HT in both ethnic groups. In conclusion, these results suggest the possible diverse roles of HPA axis dysregulation associated with higher inflammatory responses. This happens in conjunction with cardiac and vascular responses within more obese Caucasian and especially African women, respectively. / MSc (Physiology), North-West University, Potchefstroom Campus, 2009

This study focuses on self care among patients with hypertension visiting primary health care clinics in the Naledi sub-district in the North-West Province. Hypertension is one of the chronic diseases that shorten the life expectancy of many people globally and remains the most common and rapid growing cardiovascular disease, affecting 20 million people in sub-Saharan Africa. Hypertension is one of the quadruple burdens of disease associated with risky lifestyle behaviours like unhealthy diets with excessive energy intakes, physical inactivity and tobacco use. Although taking the mentioned common modif iable factors and the fact that hypertension is a manageable condition into consideration, the reality remains that the hypertension. A non-experimental, quantitative research was used to reach the aim of the study namely to identify and describe the self care abilities of patients diagnosed with hypertension, as well as explore and describe their knowledge and perceptions on hypertension. This was done by means of objectives to explore and describe self care abilities, knowledge and perceptions among patients diagnosed with hypertension; if there is an association between self care, knowledge and perception in relation to the level of education, age, income and time period and if there was association between self care and knowledge and perception of patients with hypertension visiting PHC clinics in Naledi sub-district in the North-W est Province. A literature review was first conducted for a clear understanding of self care and hypertension. Thereafter a structured questionnaire, consisting of demographical information, and questions on self care, knowledge and perception among patients with hypertension, was employed. Trained field workers assisted in data collec tion. A number of 142 questionnaires were completed by patients visiting PHC clinics. The demographic data was first analysed with results shown in the frequency table. The exploratory factor analyses were done for data reduction on self care, knowledge and perception among patients with hypertension. Descriptive statistics and Cohen effect sizes for factors on self care, knowledge and perception in relation to the level of education, age, income and other chronic illnesses of patients diagnosed with hypertension, correlational descriptive statistics between self care and knowledge and perception were done. The results revealed that patients with hypertension with low levels of education lack information with regard to hypertension. The higher the income of patients with hypertension, the better their self care abilities compared to those with low income. Patients who are English and Afrikaans speaking have more internal positive power and have better management abilities of hypertension than those who are Setswana speaking. Younger patients have more internal positive power, which declines with age. Those patients who are newly diagnosed with hypertension have more information on management abilities than those who have been diagnosed more than two years. The conclusion regarding the relationship of self care and knowledge and perception of hypertension is that the patients diagnosed with hypertension need knowledge on hypertension in order to adhere to self care abilities. The more knowledge patients have the better they will be able to adhere to self care activities. / Thesis (MCur)--North-West University, Potchefstroom Campus, 2013.

This study focuses on self care among patients with hypertension visiting primary health care clinics in the Naledi sub-district in the North-West Province. Hypertension is one of the chronic diseases that shorten the life expectancy of many people globally and remains the most common and rapid growing cardiovascular disease, affecting 20 million people in sub-Saharan Africa. Hypertension is one of the quadruple burdens of disease associated with risky lifestyle behaviours like unhealthy diets with excessive energy intakes, physical inactivity and tobacco use. Although taking the mentioned common modif iable factors and the fact that hypertension is a manageable condition into consideration, the reality remains that the hypertension. A non-experimental, quantitative research was used to reach the aim of the study namely to identify and describe the self care abilities of patients diagnosed with hypertension, as well as explore and describe their knowledge and perceptions on hypertension. This was done by means of objectives to explore and describe self care abilities, knowledge and perceptions among patients diagnosed with hypertension; if there is an association between self care, knowledge and perception in relation to the level of education, age, income and time period and if there was association between self care and knowledge and perception of patients with hypertension visiting PHC clinics in Naledi sub-district in the North-W est Province. A literature review was first conducted for a clear understanding of self care and hypertension. Thereafter a structured questionnaire, consisting of demographical information, and questions on self care, knowledge and perception among patients with hypertension, was employed. Trained field workers assisted in data collec tion. A number of 142 questionnaires were completed by patients visiting PHC clinics. The demographic data was first analysed with results shown in the frequency table. The exploratory factor analyses were done for data reduction on self care, knowledge and perception among patients with hypertension. Descriptive statistics and Cohen effect sizes for factors on self care, knowledge and perception in relation to the level of education, age, income and other chronic illnesses of patients diagnosed with hypertension, correlational descriptive statistics between self care and knowledge and perception were done. The results revealed that patients with hypertension with low levels of education lack information with regard to hypertension. The higher the income of patients with hypertension, the better their self care abilities compared to those with low income. Patients who are English and Afrikaans speaking have more internal positive power and have better management abilities of hypertension than those who are Setswana speaking. Younger patients have more internal positive power, which declines with age. Those patients who are newly diagnosed with hypertension have more information on management abilities than those who have been diagnosed more than two years. The conclusion regarding the relationship of self care and knowledge and perception of hypertension is that the patients diagnosed with hypertension need knowledge on hypertension in order to adhere to self care abilities. The more knowledge patients have the better they will be able to adhere to self care activities. / Thesis (MCur)--North-West University, Potchefstroom Campus, 2013.