Background: Calcium channel blockers are mainly divided into antihypertensive and antianginal treatment agents. In 2000 it was estimated that 972 million adults worldwide were living with hypertension and it is expected to affect 1.56 billion patients by 2025. The incremental expenditure for the antihypertensive therapeutic group in the United States of America was estimated at $US 55 billion per annum in 2006. It was stated that around seven million people in the United States of America suffered from angina, with around 400 000 new reports every year. Objective: To determine the prescribing patterns of calcium channel blocker medicine items during 2005 to 2008 in a section of the private health care sector of South Africa. Methods: A retrospective quantitative drug utilisation review was done using a medicine claims database ranging over four years from 1 January 2005 to 31 December 2008. The total medicine claims database was divided into cardiovascular medicine items and then into calcium channel blockers. These were analysed according to age as well as gender. Further analysis included adherence of calcium channel blockers as well as an analysis of prescribers of these items during the study period. Results: The total number of patients on the medicine claims database consisted of 1 509 621 patients in 2005. This number decreased to 974 497 patients in 2008. The most medicine items were dispensed in 2006 (n = 21 113 422) with an average cost of R 92.82 (SD = 196.42) per medicine item. It was noted that 16.05% (n = 242 264) of patients used at least one cardiovascular item in 2005. The percentage of cardiovascular medicine item users increased by 4.36% during the study period to 20.41% (n = 198 847) in 2008. In 2008 the cardiovascular medicine items dispensed were responsible for 19.18% (R 342 565 308.41) of the total cost of all medicine items claimed. In 2005 the results revealed that 1.63% (n = 318 258) of all medicine items dispensed were calcium channel blocker medicine items. The percentage of calcium channel blockers increased to 2.24% (n = 367 437) of the total number of medicine items in 2008. The cost prevalence index was calculated for the calcium channel blockers and the value declined from 1.5 in 2005 to 1.22 in 2008, which indicated that the items dispensed were relatively expensive, but less than in 2005. An increase of 16.17% in the usage of generic medicine items were noted from 2005 to 2008. More female patients than male patients claimed medicine items during the study period. A higher percentage of male patients used a cardiovascular medicine item as well as calcium channel blockers during the study period compared to females and a larger percentage of their medicine expenditure was used on cardiovascular medicine items as well as calcium channel blockers compared to females. The usage of cardiovascular medicine items as well as calcium channel blocker medicine items increased with patient age. In 2008, 17.98% of patients older than 65 years of age used a calcium channel blocker compared to 0.97% of patients aged > 25 <= 35 years. Only 60.34% of calcium channel blockers items were used with acceptable refill adherence rates during the study. More than a third of the calcium channel blockers medicine items used had unacceptable low adherence rates from 2005 to 2008. In each of the study years the highest potential saving with generic substitution was seen with amlodipine containing items. It was also observed that some generic substitutions could be relatively more expensive than the innovator products and an increased cost instead of a saving through generic substitution may have occurred. Conclusion: This study highlighted the prescribing patterns and cost implications of calcium channel blockers in the private health care sector of South Africa. It is recommended that a more in–depth study of the adherence of calcium channel blockers be done. This study should also include the cost strategies of generic substitution of calcium channel blockers in South Africa. / Thesis (M.Pharm (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2011.

Motivation: The prevalence of cardiovascular dysfunction, especially hypertension, in Africans has increased dramatically over the past few decades. Despite considerable in~ depth studies, cardiovascular diseases remain the leading cause of morbidity and mortality. Further escalations are predicted, especially in developing countries such as South Africa, if measures are not taken to combat the trend. Numerous cardiovascular risk factors have been investigated within African-Americans as well as Caucasians. However, it is not known to what extent African-Americans and Africans from South Africa are comparable. Therefore, it is essential to investigate risk factors and their possible contributory role in the high susceptibility of cardiovascular dysfunction in the black South African population. Aim: To investigale potential risk factors and their possible involvement and association with the high prevalence of cardiovascular dysfunction within the black South African population. Methodology: Manuscripts presented in Chapters 2, 3 and 4 made use of the data obtained from the cross-sectional SAfrEIC (The South African study regarding the influence of Sex, age and ethnicity on insulin sensitivity and Cardiovascular function) study. The study group included 756 asymptomatic, apparently healthy African men and women as well as Caucasian men and women, recruited from the North West Province, South Africa. Anthropometric and cardiovascular measurements were taken as well as their lipid profiles, fasting insulin levels, and uric acid and adiponectin levels. Independent t-tests, analyses of variance (ANOVA) and analyses of covariance (ANCOVA) were used for comparison of variables between groups to determine significant differences. Partial correlations coefficients were used to show association between variables while adjusting for confounders. Multiple analyses of covariance (MANCOVA) were performed to compare variables between the groups, whilst adjusting for relevant confounders. Stepwise multiple and single regression analyses were also used to determine and confirm the most significant associations between variables. All subjects gave informed consent in writing and the Ethics Committee of the NorthWest University approved the study, The reader is referred to the "Materials and Methods" section of Chapters 2, 3 and 4 for a more elaborate description of the subjects, study design and analytical methods used in each paper. Results and conclusions of the individual manuscripts *Results from Chapter 2 revealed significantly lower uric acid levels for African men compared to Caucasian men, Despite these lower levels. the association between uric acid and blood pressure is more pronounced within the African men. The strong positive relationship between uric acid and blood pressure might be explained by uric acid's independent relationship with vascular resistance, Uric acid also revealed a positive association with triglycerides in both the African and Caucasian men. These results suggest that uric acid per se can act as a risk factor in the development of cardiovascular dysfunction in African men, *Results from Chapter 3 showed opposing changes in insulin secretion for African men and Caucasian men with increasing age. Whereas insulin levels increased in Caucasian men with progressive age, insulin levels in African men tended to decrease with ageing. Additionally, the insulin-blood pressure relationship within African men revealed opposite results as to what was expected. While the Caucasian men revealed a more positive association between insulin and blood pressure within the younger individuals, older individuals revealed a negative association between insulin and blood pressure, This implies that the vasoconstrictory actions of insulin seem to dominate in young individuals while the vasodilatory actions of insulin take over in older individuals, The turnaround probably acts as a counter protective mechanism against age-related cardiovascular dysfunction. On the contrary, despite decreased insulin secretion in older African men, they exhibit a more positive association between insulin and blood pressure, whereas younger subjects showed a more negative association, These results might suggest dissociation between insulin and blood pressure, Insulin per se might, therefore, not act as a risk factor, but rather the lack of insulin-mediated vasodilatory effects as observed within younger Africans. *Results from Chapter 4 contradicted the notion found in the literature that age-related increase in adiponectin levels are due to impaired renal function. Although the results from this chapter confirmed a Significant association between renal function (estimated creatinine clearance) and adiponectin levels a multiple regression model revealed insulin resistance (HOMA-IR) as the major contributor to adiponectin levels. Adiponectin levels increased with progressive ageing only in the Africans. No such change was observed for the Caucasians. This might be due to development of functional adiponectin resistance or perhaps due to a decline in pancreatic cell mass with ageing. In conclusion, the cardiovascular profile of Africans seems to be more detrimentally affected compared to Caucasians. Results from this study have elucidated on the associations and potential involvement of possible risk factors including, uric acid, insulin, C-peptide, as well as adiponectin, with regards to the high prevalence of cardiovascular dysfunction within the black South African population. / Thesis (Ph.D. (Physiology))--North-West University, Potchefstroom Campus, 2010.

Background: Calcium channel blockers are mainly divided into antihypertensive and antianginal treatment agents. In 2000 it was estimated that 972 million adults worldwide were living with hypertension and it is expected to affect 1.56 billion patients by 2025. The incremental expenditure for the antihypertensive therapeutic group in the United States of America was estimated at $US 55 billion per annum in 2006. It was stated that around seven million people in the United States of America suffered from angina, with around 400 000 new reports every year. Objective: To determine the prescribing patterns of calcium channel blocker medicine items during 2005 to 2008 in a section of the private health care sector of South Africa. Methods: A retrospective quantitative drug utilisation review was done using a medicine claims database ranging over four years from 1 January 2005 to 31 December 2008. The total medicine claims database was divided into cardiovascular medicine items and then into calcium channel blockers. These were analysed according to age as well as gender. Further analysis included adherence of calcium channel blockers as well as an analysis of prescribers of these items during the study period. Results: The total number of patients on the medicine claims database consisted of 1 509 621 patients in 2005. This number decreased to 974 497 patients in 2008. The most medicine items were dispensed in 2006 (n = 21 113 422) with an average cost of R 92.82 (SD = 196.42) per medicine item. It was noted that 16.05% (n = 242 264) of patients used at least one cardiovascular item in 2005. The percentage of cardiovascular medicine item users increased by 4.36% during the study period to 20.41% (n = 198 847) in 2008. In 2008 the cardiovascular medicine items dispensed were responsible for 19.18% (R 342 565 308.41) of the total cost of all medicine items claimed. In 2005 the results revealed that 1.63% (n = 318 258) of all medicine items dispensed were calcium channel blocker medicine items. The percentage of calcium channel blockers increased to 2.24% (n = 367 437) of the total number of medicine items in 2008. The cost prevalence index was calculated for the calcium channel blockers and the value declined from 1.5 in 2005 to 1.22 in 2008, which indicated that the items dispensed were relatively expensive, but less than in 2005. An increase of 16.17% in the usage of generic medicine items were noted from 2005 to 2008. More female patients than male patients claimed medicine items during the study period. A higher percentage of male patients used a cardiovascular medicine item as well as calcium channel blockers during the study period compared to females and a larger percentage of their medicine expenditure was used on cardiovascular medicine items as well as calcium channel blockers compared to females. The usage of cardiovascular medicine items as well as calcium channel blocker medicine items increased with patient age. In 2008, 17.98% of patients older than 65 years of age used a calcium channel blocker compared to 0.97% of patients aged > 25 <= 35 years. Only 60.34% of calcium channel blockers items were used with acceptable refill adherence rates during the study. More than a third of the calcium channel blockers medicine items used had unacceptable low adherence rates from 2005 to 2008. In each of the study years the highest potential saving with generic substitution was seen with amlodipine containing items. It was also observed that some generic substitutions could be relatively more expensive than the innovator products and an increased cost instead of a saving through generic substitution may have occurred. Conclusion: This study highlighted the prescribing patterns and cost implications of calcium channel blockers in the private health care sector of South Africa. It is recommended that a more in–depth study of the adherence of calcium channel blockers be done. This study should also include the cost strategies of generic substitution of calcium channel blockers in South Africa. / Thesis (M.Pharm (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2011.

Motivation: The prevalence of cardiovascular dysfunction, especially hypertension, in Africans has increased dramatically over the past few decades. Despite considerable in~ depth studies, cardiovascular diseases remain the leading cause of morbidity and mortality. Further escalations are predicted, especially in developing countries such as South Africa, if measures are not taken to combat the trend. Numerous cardiovascular risk factors have been investigated within African-Americans as well as Caucasians. However, it is not known to what extent African-Americans and Africans from South Africa are comparable. Therefore, it is essential to investigate risk factors and their possible contributory role in the high susceptibility of cardiovascular dysfunction in the black South African population. Aim: To investigale potential risk factors and their possible involvement and association with the high prevalence of cardiovascular dysfunction within the black South African population. Methodology: Manuscripts presented in Chapters 2, 3 and 4 made use of the data obtained from the cross-sectional SAfrEIC (The South African study regarding the influence of Sex, age and ethnicity on insulin sensitivity and Cardiovascular function) study. The study group included 756 asymptomatic, apparently healthy African men and women as well as Caucasian men and women, recruited from the North West Province, South Africa. Anthropometric and cardiovascular measurements were taken as well as their lipid profiles, fasting insulin levels, and uric acid and adiponectin levels. Independent t-tests, analyses of variance (ANOVA) and analyses of covariance (ANCOVA) were used for comparison of variables between groups to determine significant differences. Partial correlations coefficients were used to show association between variables while adjusting for confounders. Multiple analyses of covariance (MANCOVA) were performed to compare variables between the groups, whilst adjusting for relevant confounders. Stepwise multiple and single regression analyses were also used to determine and confirm the most significant associations between variables. All subjects gave informed consent in writing and the Ethics Committee of the NorthWest University approved the study, The reader is referred to the "Materials and Methods" section of Chapters 2, 3 and 4 for a more elaborate description of the subjects, study design and analytical methods used in each paper. Results and conclusions of the individual manuscripts *Results from Chapter 2 revealed significantly lower uric acid levels for African men compared to Caucasian men, Despite these lower levels. the association between uric acid and blood pressure is more pronounced within the African men. The strong positive relationship between uric acid and blood pressure might be explained by uric acid's independent relationship with vascular resistance, Uric acid also revealed a positive association with triglycerides in both the African and Caucasian men. These results suggest that uric acid per se can act as a risk factor in the development of cardiovascular dysfunction in African men, *Results from Chapter 3 showed opposing changes in insulin secretion for African men and Caucasian men with increasing age. Whereas insulin levels increased in Caucasian men with progressive age, insulin levels in African men tended to decrease with ageing. Additionally, the insulin-blood pressure relationship within African men revealed opposite results as to what was expected. While the Caucasian men revealed a more positive association between insulin and blood pressure within the younger individuals, older individuals revealed a negative association between insulin and blood pressure, This implies that the vasoconstrictory actions of insulin seem to dominate in young individuals while the vasodilatory actions of insulin take over in older individuals, The turnaround probably acts as a counter protective mechanism against age-related cardiovascular dysfunction. On the contrary, despite decreased insulin secretion in older African men, they exhibit a more positive association between insulin and blood pressure, whereas younger subjects showed a more negative association, These results might suggest dissociation between insulin and blood pressure, Insulin per se might, therefore, not act as a risk factor, but rather the lack of insulin-mediated vasodilatory effects as observed within younger Africans. *Results from Chapter 4 contradicted the notion found in the literature that age-related increase in adiponectin levels are due to impaired renal function. Although the results from this chapter confirmed a Significant association between renal function (estimated creatinine clearance) and adiponectin levels a multiple regression model revealed insulin resistance (HOMA-IR) as the major contributor to adiponectin levels. Adiponectin levels increased with progressive ageing only in the Africans. No such change was observed for the Caucasians. This might be due to development of functional adiponectin resistance or perhaps due to a decline in pancreatic cell mass with ageing. In conclusion, the cardiovascular profile of Africans seems to be more detrimentally affected compared to Caucasians. Results from this study have elucidated on the associations and potential involvement of possible risk factors including, uric acid, insulin, C-peptide, as well as adiponectin, with regards to the high prevalence of cardiovascular dysfunction within the black South African population. / Thesis (Ph.D. (Physiology))--North-West University, Potchefstroom Campus, 2010.

In the latter part of the 20th century chronic diseases, especially cardio vascular-related diseases (CVDs) and Type 2 diabetes mellitus (DM) seemed to have emerged as substantial problems. This can be seen in the prevalence and the cost of CVDs in South Africa and worldwide. It was predicted that by the year 2030 more people would be dying from CVDs than from Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/Aids). The reasons for the occurrence of CVDs are linked to biological (i.e. hypertension, hyperlipidemia, obesity, insulin resistance, etc), psychological (i.e. emotional stress), and behavioural or lifestyle risk factors. It is known that physical exercise can aid in the treatment of CVDs. Institutions such as the American College of Sports Medicine (ACSM) recommended an exercise frequency of three times per week for 20 minutes. According to literature, a third of patients in exercise studies do not comply with their exercise protocol, and after three to six months, 50 percent will drop out of organised training groups. Less than a third of South Africans complied with exercising 30 minutes a day on most days of the week. Thus, there has been much interest among health-care providers to manage exercise compliance. Exercise compliance is a complex construct, and thus in the present study the role that behavioural patterns play was also investigated via psychological behavioural models. The major objectives of the study were the following: <ul> <li> Firstly, to determine if exercise compliance or non-compliance had an influence on shifts measured in the clinical parameters (i.e. blood pressure, blood lipid levels, blood glucose levels, body mass index, body fat percentage and cardiac risk percentage) over time.</li> <li> Secondly, to determine whether there were any correlation between the psychological behavioural models and the exercise compliance of the members over the course of the Best Med/Access Health-Disease Management Programme (BM/AH-DM Programme).</li></ul> In the present study, a retrospective data analysis was done on data collected from Best Med Medical Aid members (n = 400) who participated in a chronic disease management programme for three and a half years. The inclusion criteria for participation on the programme were the presence of one or more of the following CVDs namely: hypercholesterolemia, hypertension and DM. The members’ clinical parameters (height, body weight, body fat percentage, blood pressure, finger-prick non-fasting (random) blood cholesterol level, finger-prick non-fasting (random) blood glucose, sub-maximal V02 fitness test) were measured every three months. After a baseline assessment was done, an exercise programme was given to each member and a norm of exercising twice a week was prescribed. If members adhered to the norm they were considered compliant and if they did not adhere to the norm, they were considered as being non-compliant. Their exercise compliance, and relevant clinical parameters were measured over 30 months, although data analysis was only a reflection of the first 12 months’ data. At the beginning of the BM/AH-DM Programme the members’ Level of Readiness (LOR) to make a lifestyle change was measured via a questionnaire and by the end of the programme they completed an Implicit Theory Scale (ITS) questionnaire. Descriptive statistics (means, standard deviation) were used to determine the entire groups’ compliance, and to divide the group into compliant and noncompliant groups. The T-test or the Mann-Whitney Test (an equivalent nonparametric technique) was applied to determine significant differences between groups. Thus did the clinical parameters measured over time (baseline to 3 months, baseline to 6 months and baseline to 12 months), change more in the compliant than in the non-compliant group? And were there correlations between psychological questionnaires answers and the two exercise groups? The results indicated that the group’s exercise compliance trend decreased drastically over time. Statistical significant decreases were demonstrated in systolic (p = 0.007) and diastolic (p = 0.012) blood pressure, BMI (p = 0.072 and p = 0.0003), cardiac risk percentage (p = 0.003), and body weight (p = 0.003 and p = 0.0000). All of these decreases were seen in the exercise compliant group. There were no statistical correlations between the psychological questionnaires and the exercise groups. Limitations were the quality of the clinical data, the exercise compliance data that deteriorated over time, and the LOR and ITS questionnaires was neither valid nor reliable tools in making predictions regarding exercise behaviour/compliance. For future research it is recommended that measurements of blood pressure and cholesterol be done more thoroughly, and dietary fat intake must be monitored. A valid and reliable cardiac risk tool, LOR and ITS questionnaires must be designed. AFRIKAANS : Die voorkoms en kosteïmplikasies van kroniese siektetoestande in Suid–Afrika en wêreldwyd, het in die laaste gedeelte van die 20ste eeu ‘n wesenlike probleem geword. Kardiovaskulêre (KVS) siektes en tipe 2 diabetes mellitus (DM) is veral voorbeelde van sulke siektetoestande. Daar is voorspel dat in die jaar 2030, meer mense wêreldwyd aan KVS sal doodgaan, as aan Menslike Immuniteitsgebrekvirus/Verworwe Immuniteitsgebreksindroom (MIV/Vigs). Die risikofaktore wat met die oorsake van KVS geassosieer word, is die volgende: <ul> <li> Biologiese (met inbegrip van hipertensie, insulienweerstandigheid, hoë bloedcholesteroltellings, ens)</li> <li> Sielkundige (bv emosionele spanning) • Risikofaktore wat verband hou met lewenstyl.</li></ul> Literatuur bevestig dat fisiese oefening help om KVS en diabetes mellitus te behandel. Die American College of Sports Medicine (ACSM) het ‘n oefenriglyn van drie maal per week vir 20 minute lank as ‘n minimumfrekwensie daargestel. Volgens literatuur oefen ‘n derde van pasiënte wat deelneem aan oefeningnavorsingsstudies nie volgens die riglyne wat gestel word nie en binne die eerste drie tot ses maande sal 50% van die pasiënte ophou oefen. Navorsing wat op die Suid-Afrikaanse bevolking gedoen is, toon dat minder as ‘n derde 30 minute lank op meeste dae van die week oefen. Dus is die belangstelling van gesondheidsterapeute rakende die bestuur van gereelde oefeningdeelname geprikkel. Gereelde oefeningdeelname sluit ook die rol van gedragspatrone in en dus is sielkundige gedragsmodelle gebruik om dit ook in die huidige studie te ondersoek. Copyright / Dissertation (MA)--University of Pretoria, 2009 / Biokinetics, Sport and Leisure Sciences / unrestricted