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Call number: LD2668 .T4 1985 S22 / Master of Science

Background: Cardiovascular disease (CVD) is the leading global cause of death. CVD risk factors are considered intermediaries for the association between dietary fatty acids and CVD. Raised plasma total cholesterol, low density lipoprotein (LDL) cholesterol, raised triglycerides and decreased levels of high density lipoprotein (HDL) cholesterol, as well as reduced fibrinolytic potential (measured as increased clot lysis time) are known risk factors for CVD. Plasminogen activator inhibitor-1 (PAI-1) is a major inhibitor of the fibrinolytic process and an elevated PAI-1 level is therefore considered to be a potential risk factor for CVD. The growing number of controversies around the role that fat intake (more specifically the type of dietary fat) plays in CVD risk, is making it increasingly difficult for consumers and practitioners alike to form conclusions, and make recommendations and decisions regarding fat intake. Knowledge of the intake of individual fatty acids, fatty acid status (as opposed to subgroups of fat such as polyunsaturated fatty acids) and their associations with blood lipids, PAI-1act and fibrinolytic potential is lacking in black South Africans and other populations. Therefore we aimed to investigate dietary fatty acid intake, as well as plasma phospholipid fatty acid status and their associations with blood lipids, PAI-1act and clot lysis time, as a marker for fibrinolytic potential. Methods: Cross-sectional data analysis within the Prospective Rural Urban Epidemiology (PURE) baseline study of apparently healthy black South African men and women (n=1950, 35– 70 years) from rural and urban areas in the North West Province, from whom dietary data were collected. Blood lipid analyses, as well as laboratory analyses of fibrinolysis markers such as PAI-1act and clot lysis time were also performed. Plasma phospholipid fatty acid extraction and isolation were performed on a random subsample (n = 716). Results: The intake of individual fatty acids was significantly higher in urban than rural dwellers. However, the intake of omega-3 polyunsaturated fatty acids was below recommendations in all groups (rural and urban males, and rural and urban females). Total cholesterol and LDL cholesterol were higher in females than in males, with no rural‒urban differences. Intake of alpha-linolenic acid was positively associated with total cholesterol (β=0.143) and triglycerides (β=0.256) in males. The risk of having elevated LDL cholesterol also increased with increased intake of alpha-linolenic acid (OR 1.49, 95% CI 1.04, 2.14). In females, dietary arachidonic acid and eicosapentaenoic acid (EPA) were positively associated with total cholesterol and LDL cholesterol, whereas docosahexaenoic acid (DHA) was negatively associated with total cholesterol and LDL cholesterol. Dietary alpha-linolenic acid was positively correlated with plasma EPA (males r = 0.19, p = 0.002, females r = 0.25, p < 0.001) and DHA (males r = 0.33, p < 0.001, females r = 0.30, p < 0.001). Plasma DHA was positively associated with triglycerides in males (β = 0.410, p< 0.001) and in females (β = 0.379, p< 0.001). PAI-1act was positively associated with clot lysis time, and plasma myristic acid and DHA were positively associated with PAI-1act in females. However, these fatty acids were not associated with clot lysis time. Different types of plasma fatty acids were associated with PAI-1act than with clot lysis time. Plasma alpha-linolenic acid (β = 0.123, P = 0.037), mead acid (β = 0.176, P = 0.019), arachidonic acid (β = 0.253, 0.025) and omega-3 docosapentaenoic acid (omega-3 DPA) (β = 0.224, P = 0.002) were positively associated with clot lysis time, while both myristic acid (β = - 0.130, P = 0.016) and EPA (β = -0.131, P = 0.021) were negatively associated with clot lysis time in male subjects. Plasma oleic acid (C18:1n9) (β = -0.411, P = 0.001) and omega-6 DPA (C22:5n6) (β = -0.285, P = 0.001) were negatively associated with clot lysis time, while dihomogamma- liolenic acid (DGLA) (C20:3n6) were positively associated (β = 0.178, P = 0.001) with clot lysis time in females. Conclusions: These results suggest that specific individual dietary fatty acids might be associated with blood lipids in males differently than in females, irrespective of rural or urban dwelling. It is not known however, if associations would still be present under conditions of greater intake of alpha-linolenic acid. Our results further suggest that a higher percentage of alpha-linolenic acid might be converted to DHA in this population with low intake of essential and long-chain polyunsaturated fatty acids compared to populations with a high intake of these fatty acids. These results suggest that plasma phospholipid fatty acids should not be used in isolation as biomarkers for intake of fat, without taking dietary intake data into consideration also. Associations between fatty acids and clot lysis time might be independent from PAI-1act. The association between mead acid and clot lysis time indicates that clot lysis time might increase with an essential fatty acid deficiency. This may be of particular concern in this population with a documented lower fat intake. Because the study design of this study is crosssectional, it is not able to determine cause-and-effect, and results should therefore be verified with a randomised controlled trial. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015

Background: Cardiovascular disease (CVD) is the leading global cause of death. CVD risk factors are considered intermediaries for the association between dietary fatty acids and CVD. Raised plasma total cholesterol, low density lipoprotein (LDL) cholesterol, raised triglycerides and decreased levels of high density lipoprotein (HDL) cholesterol, as well as reduced fibrinolytic potential (measured as increased clot lysis time) are known risk factors for CVD. Plasminogen activator inhibitor-1 (PAI-1) is a major inhibitor of the fibrinolytic process and an elevated PAI-1 level is therefore considered to be a potential risk factor for CVD. The growing number of controversies around the role that fat intake (more specifically the type of dietary fat) plays in CVD risk, is making it increasingly difficult for consumers and practitioners alike to form conclusions, and make recommendations and decisions regarding fat intake. Knowledge of the intake of individual fatty acids, fatty acid status (as opposed to subgroups of fat such as polyunsaturated fatty acids) and their associations with blood lipids, PAI-1act and fibrinolytic potential is lacking in black South Africans and other populations. Therefore we aimed to investigate dietary fatty acid intake, as well as plasma phospholipid fatty acid status and their associations with blood lipids, PAI-1act and clot lysis time, as a marker for fibrinolytic potential. Methods: Cross-sectional data analysis within the Prospective Rural Urban Epidemiology (PURE) baseline study of apparently healthy black South African men and women (n=1950, 35– 70 years) from rural and urban areas in the North West Province, from whom dietary data were collected. Blood lipid analyses, as well as laboratory analyses of fibrinolysis markers such as PAI-1act and clot lysis time were also performed. Plasma phospholipid fatty acid extraction and isolation were performed on a random subsample (n = 716). Results: The intake of individual fatty acids was significantly higher in urban than rural dwellers. However, the intake of omega-3 polyunsaturated fatty acids was below recommendations in all groups (rural and urban males, and rural and urban females). Total cholesterol and LDL cholesterol were higher in females than in males, with no rural‒urban differences. Intake of alpha-linolenic acid was positively associated with total cholesterol (β=0.143) and triglycerides (β=0.256) in males. The risk of having elevated LDL cholesterol also increased with increased intake of alpha-linolenic acid (OR 1.49, 95% CI 1.04, 2.14). In females, dietary arachidonic acid and eicosapentaenoic acid (EPA) were positively associated with total cholesterol and LDL cholesterol, whereas docosahexaenoic acid (DHA) was negatively associated with total cholesterol and LDL cholesterol. Dietary alpha-linolenic acid was positively correlated with plasma EPA (males r = 0.19, p = 0.002, females r = 0.25, p < 0.001) and DHA (males r = 0.33, p < 0.001, females r = 0.30, p < 0.001). Plasma DHA was positively associated with triglycerides in males (β = 0.410, p< 0.001) and in females (β = 0.379, p< 0.001). PAI-1act was positively associated with clot lysis time, and plasma myristic acid and DHA were positively associated with PAI-1act in females. However, these fatty acids were not associated with clot lysis time. Different types of plasma fatty acids were associated with PAI-1act than with clot lysis time. Plasma alpha-linolenic acid (β = 0.123, P = 0.037), mead acid (β = 0.176, P = 0.019), arachidonic acid (β = 0.253, 0.025) and omega-3 docosapentaenoic acid (omega-3 DPA) (β = 0.224, P = 0.002) were positively associated with clot lysis time, while both myristic acid (β = - 0.130, P = 0.016) and EPA (β = -0.131, P = 0.021) were negatively associated with clot lysis time in male subjects. Plasma oleic acid (C18:1n9) (β = -0.411, P = 0.001) and omega-6 DPA (C22:5n6) (β = -0.285, P = 0.001) were negatively associated with clot lysis time, while dihomogamma- liolenic acid (DGLA) (C20:3n6) were positively associated (β = 0.178, P = 0.001) with clot lysis time in females. Conclusions: These results suggest that specific individual dietary fatty acids might be associated with blood lipids in males differently than in females, irrespective of rural or urban dwelling. It is not known however, if associations would still be present under conditions of greater intake of alpha-linolenic acid. Our results further suggest that a higher percentage of alpha-linolenic acid might be converted to DHA in this population with low intake of essential and long-chain polyunsaturated fatty acids compared to populations with a high intake of these fatty acids. These results suggest that plasma phospholipid fatty acids should not be used in isolation as biomarkers for intake of fat, without taking dietary intake data into consideration also. Associations between fatty acids and clot lysis time might be independent from PAI-1act. The association between mead acid and clot lysis time indicates that clot lysis time might increase with an essential fatty acid deficiency. This may be of particular concern in this population with a documented lower fat intake. Because the study design of this study is crosssectional, it is not able to determine cause-and-effect, and results should therefore be verified with a randomised controlled trial. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015

Prediction for future coronary artery disease (CAD) from high-density lipoprotein (HDL) and triglyceride (TG) measurements are based off of a single measurement that has been shown to be variable. To better determine risk for CAD based on blood lipids, studies in the postprandial state are warranted. To assess the reproducibility of TG clearance, 10 men underwent three trials of a 70g oral fat loading test with blood samples collected every two hours for eight hours. These trials were all scheduled at least one week apart. Men who had fasting TG concentrations > 250 mg - dL -' were excluded from the study. Each subject presented to the laboratory having abstained from exercise for 24 hours and alcohol 72 hours prior to the upcoming trial. Each subject was also provided with a standardized frozen dinner to eat the night before at a time which allowed the subject to be 12 hours fasted for the next days' trial. To specifically assess postprandial lipemia, TG concentrations were plotted against bi-hourly collection times to form a curve. The area under this curve was then calculated to determine PPL area. Itwas found that there was no significant difference in area under the TG curve (p = 0.25) for any of the three trials (1096 ± 168, 948 ± 105, and 995 ± 127 mg - dL -' - 8 • hr-' respectively for trials one, two, and three). Pearson correlations between trials were 0.79 for trials one and two, 0.82 for trials two and three, and 0.90 for trials one and three. Also, there was no significant difference in peak TG (p = 0.34) on each of the three trial days (167 ± 27, 150 ± 16, and 151 ± 19 mg • dL -1 in peak TG for trials one, two, and three respectively). Time taken to reach peak TG concentrations (p = 0.20) or time to return to baseline TG (p = 0.27) were not significantly different across three trial days. The men in this study reached peak TG concentrations in this study in 3.2 ± 0.5, 4.0 ± 0.4, 4.0 ± 0.3 hours respectively for trials one, two, and three. Time to return to baseline was 6.8 ± 0.6, 7.4 ± 0.4, 7.8 ± 0.4 hours for trials one through three respectively. Correlations between trials and the lack of a difference between trials using repeated measures ANOVA in regards to PPL area gives some preliminary evidence that some postprandial measures such as PPL area and can be reproduced across trials. However, the intra-individual variation was 19 ± 4% which provides no additional support for reproducibility of PPL. Additionally, results from this study, as well as all others pertaining to the study of reproducibility of PPL are specific to the protocol used and the method of interpretation. / School of Physical Education

Les maladies cardiovasculaires (MCV) sont en augmentation au niveau mondial et sont désormais un problème de santé publique coûteux. La suralimentation et le manque d'activité physique sont des facteurs clé dans le développement pathologique. Ces dernières années, les études sur la pathogenèse des MCV ont mis en évidence de nombreux facteurs contribuant au développement de ces pathologies complexes, notamment le surpoids, l'obésité centrale, le stress oxydant, l'inflammation vasculaire et systémique, la résistance à l'insuline ou encore la dysfonction endothéliale. La prévention de ces désordres est donc la cible des stratégies pharmaceutiques et diététiques et les polyphénols ont d'ores et déjà démontré des effets bénéfiques et préventifs. Parmi les 8000 composés phénoliques décrits à ce jour, le resvératrol a émergé en tant que candidat robuste dans la prévention des pathologies liées à la nutrition. L'objectif de ce travail a été d'étudier les potentialités d'action d'un extrait de sarment de vigne (Vineatrol®) et de vins rouges riches en resvératrol et ses oligomères, sur un modèle animal d'athérosclérose nutritionnellement induite. La première partie de cette étude a consisté à mettre au point un régime alimentaire déclenchant au mieux l'athérosclérose précoce chez le hamster Syrien doré. A partir de ce modèle, un effet préventif du Vineatrol® a été mis en évidence : le Vineatrol® induit une diminution des dépôts lipidiques aortiques mais améliore également le statut oxydatif et inflammatoire des animaux. Dans une troisième partie, des vins rouges enrichis en Vineatrol® ont démontré des effets préventifs sur certains facteurs de risque de la pathologie athéromateuse et sur les désordres liés à la consommation d'un régime gras. Des mécanismes d'action possibles, expliquant les effets bénéfiques de ces vins, ont été envisagés et recherchés. Ces mécanismes pourraient impliquer une modulation de la voie du NF-κB et/ou de SIRT1. Le degré d'importance de ces différentes voies devra être confirmé. / Cardiovascular diseases (CVD) are increasing globally and are now an expensive public health problem. Overnutrition and lack of physical activity are key factors in the disease development. In recent years, studies on the pathogenesis of CVD showed many factors contributing to the development of these complex diseases including overweight, centralobesity, oxidative stress, vascular and systemic inflammation, insulin ressitance or endothelial dysfunction. Prevention of these disorders is the focus of pharmaceutical and dietarystrategies and polyphenols have already demonstrated beneficial and preventive effects. Among the 8000 phenolic compounds described to date, resveratrol has emerged as a strong candidate for the prevention of nutrition-related diseases.The objective of this work was to study the potential action of vine shoot extract (Vineatrol®) and red wines rich in resveratrol and its oligomers, in an animal model of nutritionallyinduced atherosclerosis.The first part of this study was to develop a diet triggering the best early atherosclerosis in theSyrian golden hamster. From this model, a preventive effect of Vineatrol® was highlighted: Vineatrol® induces adecrease in aortic lipid deposition but also improves the oxidative and inflammatory status of the animals. In the third part , Vineatrol®-enriched red wines showed preventive effects on risk factors foratherosclerotic disease and disorders related to the consumption of a high-fat diet. Possible mechanisms of action, explaining the beneficial effects of these wines have been consideredand sough. These mechanisms could involve modulation of the NF-κB and/or SIRT1pathways. The degree of importance of these different pathways will have to be confirmed.

M.Phil. / Numerous studies have demonstrated the favourable effects of aerobic training on blood lipid profiles. However, few studies have generated conclusive data on the effects of dynamic resistance training (DRT) on blood lipid profiles. In order to evaluate the effect of DRT on lipoprotein-lipid profiles, a group of 28 sedentary but healthy males (mean age 28 years and 7 months) were matched and randomly assigned into a control/non-exercising (n = 15) or an experimental (n = 13) group. To control for variations in lipoprotein-lipid profiles, the present investigation recorded dietary intake and smoking behaviour in an attempt to account for any changes in lipoprotein-lipid profiles over the eight-week period. The experimental group (EG) exercised using DRT for a period of eight weeks and was monitored for changes in lipoprotein-lipid profiles. The control group (CG) took part in no structured exercise throughout the eight-week period. The experimental training programme consisted of nine exercises (dumbbell (D/B) shoulder shrugs, D/B lateral shoulder raises, seated chest press, latissimus dorsi pulldowns, seated pulley rows, biceps curls, triceps extensions, crunchies and unilateral leg press). These exercises were performed at 60% of one repetition maximum (1-RM) and were performed three times per week on non-consecutive days. Serum was analyzed for total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). In addition to this, the TC: HDL-C and LDL-C: HDL-C ratios were calculated. The Independent t-Test and the Paired t-Test were utilized to determine the significance (at a 95% confidence level (p ¡Ü 0.05)) of the lipoprotein-lipid profile changes from pre- to post-test. These student t-Tests demonstrated no statistically significant changes in TC, TG, LDL-C, HDL-C, TC: HDL-C ratios and LDL-C: HDL-C ratios in the EG. However, the present investigation did demonstrate the following changes: a 0.50% decrease in TC, a 1.74% increase in TG, a 2.95% decrease in LDL-C, a 4.61% increase in HDL-C, a 4.12% decrease in the TC: HDL-C ratio and a 5.96% decrease in the LDL-C: HDL-C ratio. The lack of statistically significant changes in the individual lipoprotein-lipid parameters could not have been affected by diet, cigarettes smoked daily, aerobic fitness and/or body mass, since these parameters did not change significantly from pre- to post-test. Specifically, both the EG and CG demonstrated no statistically significant changes in intake in total calories consumed, carbohydrates, proteins, fats (monounsaturated, polyunsaturated and saturated fatty acids), cholesterol and fibre. Although the present investigation findings suggest that this study¡¯s eight-week combination of dose, workload, number of repetitions and order and number of exercises may not have been sufficient to elicit significant improvements in lipoprotein-lipid parameters in this population of sedentary but healthy males, it is the opinion of the author that DRT should be included with aerobic modes of exercise. DRT should be used in conjunction with aerobic modes of exercise for its additional benefits. Such additional benefits include inter alia: increased strength, increased lean tissue mass, increased maintenance of metabolically active tissue in the elderly and increased muscle control. / Prof. J.M. Loots Mr. L. Lategan