Background:Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. A major risk factor for CVD is hypercholesterolaemia. As a result the South African scientific community has updated its clinical guidelines for CVD management by adoption of the current European cardiovascular disease guidelines. The South African Not at Goal Study (SA-NAG) was a survey to determine the percentage of patients, on lipid-lowering therapy, who are not achieving guideline specified low density lipoprotein cholesterol (LDL-C) goals. Design: A cross-sectional study. Methods: In this study, dyslipidaemic and/or CVD patients on lipid lowering therapy for > 4 months were enrolled. Volunteers had their demographic data and previous medical history documented. Fasting lipid and blood glucose levels were measured in all subjects. Results: In total 1201 patients (age 58±11.4 yrs) were recruited by physicians and general practitioners. Under the new guidelines, 41% of patients are defined as Low Risk (LR) and 59% of patients are High Risk (HR) for CVD. LDL-C target goals were not achieved in 63% of LR patients and 77% of HR patients (71% overall). LR and HR patients, who were not at their LDL-C goal, were on average 19% (0.7 mmol/L) and 31% (1.1 mmol/L) above their LDL-C target levels respectively. Conclusions These results, in light of the new guidelines, suggest that a considerable percentage of patients will fall into the category of “not at goal” LDL-C. The adoption of the new guidelines will necessitate enhanced disease management to reduce the extent of hypercholesterolaemia and risk for CVD.

Hypercholesterolaemia (high cholesterol) is a risk factor for atherosclerosis, a major contributor to cardiovascular disease. Much has been written on managing high cholesterol levels including the use of drug therapy and recommendations about beneficial lifestyle changes relating to nutrition and exercise in particular. Despite this, and the need for patients to engage in self management of a condition which may impact invisibly on their health, little is known about how people living with this risk factor actually manage.The purpose of this grounded theory study is to investigate people's process of living with high cholesterol. Eight participants with self reported high cholesterol levels were interviewed and their data analysed using the process of constant comparative analysis, open coding, selective coding and theoretical coding. A substantive theory in the area of patient self-management of high cholesterol levels was generated through the use of this approach. The theory developed was the basic social process of Maintaining Enjoyment of Life, with two supporting categories, Accepting and Getting On With It.Maintaining Enjoyment of Life was central to the participants' process of living with high cholesterol and the recommended health directives. The identification of this basic social process adds to our understanding of the influences on individuals' motivation for behaviour change and adherence to lifestyle changes. The findings of this study provide understanding that issues relating to behaviour change and adherence are not so much about denying that anything is wrong or not taking personal responsibility, but more about trying to hold on to something important, around which the participants' lives revolve. This is Maintaining Enjoyment of Life. By focussing on this basic social process, which is grounded in the participants' data, health professionals could work more effectively towards empowering patients to identify their own individualised strategies for self-management of high cholesterol. In addition, health directives could focus more on process rather than on do(s) and don't(s).

Reduced high-density lipoprotein cholesterol (HDL-C) concentrations are a major risk factor for cardiovascular disease. Intense interest recently has been in identifying the genetic factors that contribute to an aberrant HDL-C phenotype. Finding genetic factors associated with low HDL-C concentrations in New Zealanders was the major aim of this study, with a similar analysis aimed at finding factors associated with high HDL-C concentrations included. The study began with an investigation of a New Zealand family with HDL-C deficiency. The proband had virtually no HDL-C, and was homozygous for an R1068H mutation in the ABCA1 gene. Nineteen relatives were recruited into the study, and an analysis aimed at finding the underlying cause for the disparate HDL-C phenotypes amongst H1068 carriers initiated. A further investigation into HDL-C levels aimed to find other genetic factors that contribute to HDL-C in New Zealanders. Subjects were selected from those taking part in the Otago Vascular Disease study, and placed into three groups based on their HDL-C lipid measurement: low (n=154), mid (n=105), and high (n=102) HDL-C. Mutations in ABCAI and the apolipoprotein AI gene (APOAI) were identified in subjects with low HDL-C. Polymorphisms in ABCA1 and APOAI were also investigated as contributors to HDL-C concentrations. Seventeen SNPs in functionally relevant regions were genotyped in the three HDL-C groups. Five single polymorphisms and one polymorphism haplotype showed a statistically significant association with HDL-C concentrations. The final analysis investigated plasma lipoprotein compositions in individuals with low HDL-C to identify if other lipoprotein abnormalities concurred. Individuals with HDL-C below 0.65 mmol/L were almost invariably associated with triglyceride-rich VLDL and/or triglyceride-rich LDL. This finding may have relevance for an increased atherosclerotic risk for those with low HDL-C.

The presence of cholesterol is critical in defining a dynamic lateral structure in pulmonary surfactant membranes, including the segregation of fluid-ordered and fluid-disordered phases. However, an excess of cholesterol has been associated with impaired surface activity both in surfactant models and in surfactant from injured lungs. It has also been reported that surfactant protein SP-C interacts with cholesterol in lipid/protein interfacial films. In the present study, we have analyzed the effect of SP-C on the thermodynamic properties of phospholipid membranes containing cholesterol and on the ability of lipid/protein complexes containing surfactant proteins and cholesterol to form and re-spread interfacial films capable of producing very low surface tensions upon repetitive compression-expansion cycling. We have also analyzed the effect of cholesterol on the structure, orientation and dynamic properties of SP-C embedded in physiologically relevant model membranes.

Cholesterol is an important component in maintaining the structure and dynamics of cell membranes. Dysregulation of cholesterol results in detrimental changes including decreased fluidity of the membrane and changes in membrane permeability. Because cholesterol is synthesized and regulated in the liver, many liver diseases are accompanied by dysregulation of cholesterol. And this dysregulation could alter transportation of small molecules through the cell membrane of such diseased cells. This study will focus on the diffusion of three small-molecule drugs through liver cell membranes with varying cholesterol concentration using a molecular dynamics approach. Results from this study could provide more detail about cholesterol’s effect on liver cell membrane permeability.

Thesis (M.S.)--Miami University, Dept. of Chemistry and Biochemistry, 2003. / Title from first page of PDF document. Document formatted into pages; contains ix, 87 p. : ill. Includes bibliographical references (p. 85-87).

published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No abstract available. / Thesis (M.Sc.)-University of Durban-Westville, 1990.

No description available.