Introduction: Social relationships are increasingly being acknowledged as determinants of wellbeing and health in later life. We know that people who feel lonely – i.e. who are unhappy about their relationships – or who are socially isolated – i.e. have few ties or contacts with others – are more likely to experience early death. Whether they are at greater risk of morbidity is unclear. Aim: This thesis examines whether loneliness and social isolation are risk factors for developing ill health, with a primary focus on incident cardiovascular disease (CVD). The aim is to gauge the potential health gain from tackling loneliness and social isolation. Methods: Four pieces of empirical research make up the main body of my thesis. First, I designed a novel framework for distinguishing between measures of loneliness and social isolation. I then systematically reviewed the evidence from longitudinal observational studies on loneliness, social isolation and incident CVD. I studied changes in loneliness and social isolation over time in the English Longitudinal Study of Ageing (ELSA), a cohort of adults aged over 50 years old. Finally, I investigated associations between loneliness and social isolation over time, and incident CVD. Results: My systematic review found that loneliness and social isolation were associated with a 29% increase in risk of incident coronary heart disease (relative risk: 1.29, 95% CI 1.04 to 1.59) and a 32% increase in risk of stroke (relative risk: 1.32, 95% CI 1.04 to 1.68). Among ELSA participants, patterns of social relationships varied substantially over time, both within and between individuals. In survival analyses of ELSA data, loneliness but not social isolation was identified as a risk factor for incident CVD. Conclusions: Weaker social relationships are risk factors for developing CVD. Intervening to tackle loneliness and social isolation has the potential to improve health outcomes in later life.

Introduction: There is a need to study the level of percutaneous coronary intervention (PCI) care in the UK to promote improvements in care for all patients with cardiovascular disease. The aim of this thesis was to utilise contemporary population-based data to perform a number of investigations and answer several important questions regarding the level of care provided to patients who have undergone PCI in the UK on the basis of outcomes including survival. Methods: A linked population-based study using the prospectively collected British Cardiovascular Intervention Society (BCIS) registry of patients who have undergone PCI in the UK since January 2005. Three main analyses were performed and for each part; a literature review, analysis (descriptive statistics, comparisons, adjusted associations and survival), multi-level modelling and fit for purpose imputation were conducted. Results: In the first analysis, 5,065 patients with unprotected left main stem disease (UPLMS) were studied. More than half of patients treated with PCI to the UPLMS presented acutely, their early and late mortality were significantly worse than that for elective patients. Cardiogenic shock was common in ST elevation myocardial infarction (STEMI) and associated with a 1 in 2 risk of early mortality. In acute patients, radial access was associated with improved early outcomes. In the second analysis, 10,827 patients with UPLMS were studied. The number of acute patients with UPLMS PCI increased over the years with stable early and late mortality rates. In the third analysis, 98,637 patients with STEMI were studied. The survival of primary PCI patients was worse than that of facilitated and rescue mainly because majority of the procedures were performed after more than two hours from the onset of symptoms. Old age, cardiogenic shock, more than two hours delay before intervention, inter-hospital transfer and being already in a cardiac centre were independent predictors of worse survival in primary interventions. Conclusions: The novel prospective data used in this thesis have provided the opportunity to gain more knowledge and understanding of the quality of care provided to patients following PCI which represents a step forward in the assessment and improvement of cardiovascular health services in the UK.

Despite continuing advances in the surgical management of abdominal aortic aneurysm (AAA), there is a lack of clear evidence relating to the impact of the condition and its treatment on patients’ quality of life (QoL). Furthermore, little is known about symptoms experienced by these patients or their satisfaction with treatment. This thesis describes the design, development and validation of three new patient reported outcome measures (PROMs) to assess QoL, symptoms and treatment satisfaction in patients with AAA: The Aneurysm-Dependent Quality of Life questionnaire (AneurysmDQoL) is an individualised measure of the impact of AAA on patients’ QoL, comprising 22 domains chosen specifically for their relevance to patients with AAA and 2 overview items to assess overall QoL and AAA-related QoL more broadly. The Aneurysm Symptom Rating Questionnaire (AneurysmSRQ) is a 44-item measure assessing physical and psychological symptoms reported by patients with AAA. The Aneurysm Treatment Satisfaction Questionnaire (AneurysmTSQ) contains 11 items measuring satisfaction with treatment and includes subscales suitable for patients both pre- and post-intervention. The development process has shown that the new tools have good face and content validity for patients with AAA. Psychometric analyses have confirmed that they also have clear structure, good internal consistency reliability and strong test-retest reliability. The questionnaires are now ready for use in clinical trials and routine care. Observational data derived with the new tools are also presented from a cross- sectional cohort of 194 patients with AAA. Results, though largely non­significant, showed interesting trends. The impact of AAA repair on QoL appeared to worsen progressively after open repair (OR) and improve progressively after endovascular aneurysm repair (EVAR). Conversely, symptoms became progressively worse after EVAR and progressively better after OR. Information and understanding were key sources of dissatisfaction before intervention, whereas postoperative dissatisfaction was related to bother from symptoms, follow-up and feedback about scan results.

Background: Hypertension is a global public health problem. It is the number one risk factor for mortality and the third leading cause of disability-adjusted life-years (DALYs) worldwide. The burden of the disease is more severe in low- and middle-income countries, where prevalence estimates are projected to increase by 30% over the next decade. This is not surprising owing to the on-going epidemiological transition taking place in these countries, where the interplay between social factors and disease is highly pertinent. However, evidence on the burden of hypertension and its determinants in low- and middle-income countries are limited. The overall aim of this research is to examine the prevalence and status of hypertension in low- and middle-income countries. The definition of hypertension used in this research is blood pressure measurement of ≥140 /90 mmHg (SBP/DBP), the use of antihypertensive medication, or self-reported physician diagnosis of hypertension. Objectives: -To estimate the overall prevalence of hypertension in low- and middle-income countries. -To examine the socio-demographic determinants of hypertension in low- and middle-income settings. -To examine the geographic variation of hypertension prevalence in selected low-and middle-income countries. -To interpret the findings and discuss their implications for practice/policy and future research. Methods: A systematic review and meta-analysis was conducted to provide overall and regional estimates of hypertension prevalence across low- and middle-income countries, and to examine patterns of the disease across different socio-demographic characteristics in these settings. Studies reporting hypertension prevalence in low- and middle-income countries were sought from electronic databases and grey literature. The data from these studies were analyzed using random-effects meta-analyses and sub-group analyses. Secondary data analyses of DHS datasets were also conducted to estimate hypertension prevalence and examine its geographic variation in selected low- and middle-income countries with hypertension data, while accounting for a number socio-demographic characteristics. The secondary data analyses entailed logistic regression and Bayesian geo-additive analyses. Odds ratios with 95% confidence intervals were reported for the logistic regression analyses, whereas posterior odds ratios with 95% credible intervals were reported for the Bayesian geo-additive analyses. Results: The systematic review included 242 studies, comprising 1,494,609 adults from 45 countries. The overall prevalence of hypertension was 32.3% (95% confidence interval [CI] 29.4–35.3) with the Latin America and Caribbean region reporting the highest prevalence (39.1%, 95% CI 33.1–45.2). Prevalence was also highest in upper-middle income countries (37.8%, 95% CI 35.0–40.6) and lowest in low-income countries (23.1%, 95% CI 20.1–26.2). Prevalence among adults ≥65 years was substantially higher than adults < 65 years; however, there was no significant sex-difference overall (31.9% vs 30.8%, p=0.6). Prevalence was generally higher among the non-educated compared to educated people (49.0% vs. 24.9%, p < 0.05), among overweight/obese persons compared to normal weight (46.4% vs. 26.3%, p < 0.05), and among urban settlers compared to rural (32.7% vs 25.2%, p=0.0005). Meta-regression showed that combined overweight/obesity (p < 0.05) and being uneducated (p < 0.05) significantly accounted for between-study heterogeneity in hypertension rates The secondary analysis comprised data on 93,247 respondents in 10 selected countries (Albania, Armenia, Azerbaijan, Ukraine, Uzbekistan, Egypt, Morocco, Lesotho, Senegal and Maldives). The prevalence of hypertension was lowest in Morocco (5.4%) and highest in Albania (22.7%). Age was the most consistent predictor of hypertension. Being employed was protective in the Eastern European countries (Albania, Armenia, Azerbaijan, Ukraine and Uzbekistan) (p < 0.05 for each) and in African countries such as Egypt and Senegal (p < 0.05 for each). Education was protective in Egypt, Senegal and Maldives (p < 0.05 for each), but may be a strong determinant in Lesotho given the extremely high literacy rates in the country. Examining the geographic variation of hypertension revealed that Tirana and Elbasan districts had the highest burden of hypertension compared to other districts in Albania; Sharkia and Kalyoubia districts had the highest burden of hypertension compared to other districts in Egypt; while Quthing and Maseru districts had the highest burden of hypertension in Lesotho. Conclusion: Overall, the findings provide contemporary and up-to-date estimates that reflect the significant burden of hypertension in low- and middle-income countries and evidence that hypertension remains a major public health issue in these settings. The findings also suggest that addressing the wider social determinants of hypertension, such as illiteracy and unemployment, may reduce overall prevalence of the disease in low- and middle-income countries.

There are in excess of one million people across the UK people living with atrial fibrillation (AF), a long term condition that can lead to stroke and other complications, costing the NHS over £2,200 million per year. However little is known about the experience of living with AF and what patients' perceptions are of the support they receive from health professionals. In order to ensure that patients have the best possible experience of care, healthcare professionals need to have an understanding of how patients view their condition and the type of support they would like to receive from the professionals involved in their care. Although there has been a significant amount of work investigating social support for people with health conditions, there has been little work exploring support provided by healthcare professionals, defined in this study as professional support. This study aimed to investigate and assess the professional support needs of people with AF to develop knowledge and understanding in this field. A theoretical framework for professional support was developed based on the tri-dimensional model of social support and was used to direct the research. Using an exploratory sequential design, a two phase mixed methods study was undertaken. Initially, qualitative interviews were undertaken with patients recruited from outpatient arrhythmia clinics at one National Health Service (NHS) hospital and identified from the perspective of the patient how, when and where healthcare professionals did/did not provide support. Key components of emotional, informational and tangible professional support were identified from thematic analysis of the interview data and used to inform the development of a quantitative questionnaire. Physical activity, exercise and the impact of AF on activity levels were identified by participants as important and so were also included. The quantitative online questionnaire was completed by patient members of the Atrial Fibrillation Association (AFA). To examine relationships between variables, statistical analyses were performed using Fisher's exact test and indicated that people with AF had a range of emotional, informational and tangible professional support needs. Different subgroups of people with AF had different professional support needs: People with more severe symptoms needed more emotional support as well as more tangible support and people with paroxysmal AF needed more informational support. People undergoing ablation as treatment for their AF had specific informational and emotional needs for support. AF played a significant part in the lives of people with AF by modifying activities of daily living and shaping physical activity behaviour and choice of activities. People with AF therefore needed professional support in maintaining and/or increasing their levels of activity. Considering the specificity of professional support, GPs, cardiologists and arrhythmia nurse specialists were identified as most supportive, with GPs and cardiologists also considered as the least helpful at providing support, indicating a variation in professional support. The findings from this study contribute to the limited body of knowledge describing the experience of living with AF and provide healthcare professionals with a unique understanding of how best to provide professional support. The tri-dimensional model provides detailed knowledge of the components of informational, emotional and tangible support that people with AF would like to receive from the healthcare professionals involved in their care. The findings indicate there are differing support needs for different subsets of people with AF demonstrating a need for individualised professional support. The theoretical framework for professional support used in this study provides a model that could be used in future research studies to identify the types of professional support required by patients and to identify subgroups of patients who may require additional professional support. By accurately identifying the needs of patients, this will ensure that healthcare professionals are able to deliver effective patient centred services, leading to an improved patient experience and the delivery of high quality patient care.

The National Health Service (NHS) in England is changing, not only in terms of the technical aspects of care (such as that afforded by new technology), but also in the way in which care is delivered to patients. For example, due to the increasing pressures being placed upon health services, hospitals need to develop innovative ways to reduce the length of time patients actually spend in hospital. Whilst this improves capacity planning, bed management and patient flow, it also seeks to ensure improved patient safety by delivering care and ongoing treatment in the most appropriate setting. However, discharging patients from hospital can be challenging and fraught with complexities. Therefore, the efficient and effective management of this process can have a considerable impact on subsequent clinical outcomes and readmission rates. As such, effective discharge planning and practice has become an integral part of health service policy and, in recent years, there has been an increased emphasis placed on the contribution nurses make to this process (Department of Health, 2002; 2005a; 2005b). New recommendations from the Kings Fund (Seale, 2016) suggest that a collaborative relationship between patients, carers, third sector parties and communities is central to the future of the NHS. This is because these perspectives are fundamental; indeed, patients are the reason the NHS exists. Since 2010, this has been the aim of my doctoral research ― to explore a shared leadership approach in determining the principles of care. The purpose of this study is to gain an insight into (and a greater understanding of) patient experiences during the discharge process following percutaneous coronary intervention (PCI) after myocardial infarction (MI) ― commonly known as a heart attack. PCI is a relatively new procedure; since its implementation it has resulted in patients staying in hospital for less than three days. Previous management would regularly result in patients remaining in hospital for longer than seven days. However, reducing the length of stay has potentially impacted how information and communication are both provided and understood by patients on discharge from acute hospital care. Previous research such as Hainsworth (2006), Department of Health (DoH) (2004) and Picker (2010) suggests that whilst there has been a great deal of emphasis placed on policy, there still remains scope for improvement in practice. As qualitative research is a form of social enquiry that focuses on the way people make sense of their experiences and the world in which they live, this research focuses on individuals who have had a heart attack and have then undergone the same treatment. The aim is to understand, describe and interpret their experiences, behaviour and feelings by looking at social processes and interactions. This was based on undertaking three separate focus groups involving patients, clinicians and members of the management team from a local NHS acute hospital in West London. Furthermore, in-depth, semi-structured interviews with eight patients were conducted. The idea behind surveying patients', clinical staff and managers narratives/opinions, was to establish a holistic view of discharge planning and practice. Recommendations for change could then be made dependant on these findings, in order to improve the effectiveness and efficiency of this process, in addition to patients’ experiences. Following the completion of the focus groups and semi-structured interviews, analysis was undertaken to identify whether any common themes emerged across the three different groups. Although the narratives identified varying views, the most significant of the emerging themes was that of communication and the attitude of staff. Indeed, further analysis confirmed that communication was a prevalent issue in all three focus groups. The findings suggest patients have specific individual needs; this would not be surprising given the treatment and care received. Communication was also noted to be a major theme for patients; whilst clearly the majority of patients were relatively happy with the care received, they remained keen to make suggestions for improvement. The attitude of staff also featured strongly; patients were keen to suggest the changes they required and their rationale for these suggestions. The clinicians' themes mirrored the patients' themes, whilst also incorporating resource and innovation. The managers' themes commonly focused on service and proposed new ways of working, which included 'joined-up' working across acute and community services. Furthermore, the clinicians' and managers’ themes recognised that the attitudes of all groups of staff remained a challenge. In conclusion, this study has demonstrated the requirement for and the importance of effective communication throughout the entire discharge process. The aims are as follows: to ensure that post-procedure patients are discharged home or into a community setting safely; that they receive the right care, treatment and information in the most appropriate setting; and that they find and use ways to facilitate their recovery. Furthermore, this study has validated the importance of empowering patients to live with their diagnosed condition/disease by enabling the provision of support post-discharge. To this end, there is a need to ensure that positive values (such as empathy and compassion) remain a core part of the discharge planning process. This can be achieved by recognising each patient as an individual who is trying to make sense of a daunting life-changing experience whilst maintaining their own core belief and value systems. As a result, recommendations for improvements and change within this study have been based upon these findings. Further research needs to be defined to ensure that discharging patients from an acute hospital to their home or community setting remains both safe and effective, whilst also being informative and empowering.

Cardiovascular disease (CVD) is the biggest killer of people in western civilisation. Age is a significant risk factor for the development for CVD, and treatments and therapies to address this increased risk are crucial to quality of life and longevity. Exercise is one such intervention which has been shown to reduce CVD risk. Age is also associated with endothelial dysfunction, reduced angiogenic capabilities, and reduced ability to repair the vessel wall. Circulating angiogenic cells (CACs) are a subset of circulating cells which assist in the repair and growth of the vasculature and in the maintenance of endothelial function. Reductions in these cells are observed in those with vascular disease compared to age-matched healthy controls. Exercise may reduce CVD risk by improvements in number and/or function of these CACs. Data was collected from human volunteers of various ages, cardiorespiratory fitness (CRF) levels and latent viral infection history status to investigate the effects of chronological age, CRF, viral serology and other lifestyle factors, such as sedentary behaviours and exercise on CACs. The levels of CACs in these volunteers were measured using four colour flow cytometry using various monoclonal antibodies specific to cell surface markers that are used to identify specific subsets of these CACs. In addition, the response to acute exercise of a specific subset of these CACs, termed ‘angiogenic T-cells' (TANG) were investigated, in a group of well-trained males aged 20-40 years, using a strenuous submaximal exercise bout. Advancing age was associated with a decline in various subsets of CACs, including bone marrow-derived CD34+ progenitors, putative endothelial progenitor cells (EPCs) and also TANG cells. Individuals with a higher CRF were more likely to have higher circulating numbers of TANG cells, particularly in the CD4+ subset. CRF did not appear to modulate CD34+ progenitors or EPC subsets. Increasing sitting time was associated with reduction in TANG cells, but after correcting for the effects of fitness, sitting time no longer negatively affected the circulating number of these cells. Acute exercise was a powerful stimulus for increasing the number of TANG cells (140% increase), potentially through an SDF-1:CXCR4-dependent mechanism, but more studies are required to investigate this. Latent CMV infection was associated with higher number of TANG cells (CD8+), but only in 18-40 year old individuals, and not in an older age group (41-65 year old). The significance of this has yet to be understood. In conclusion, advancing age may contribute to increased CVD risk partly due to the observed reductions in angiogenic cells circulating in the peripheral compartment. Maintaining a high CRF may attenuate this CVD reduction by modulating TANG cell number, but potentially not CD34+ progenitor or EPC subsets. Acute exercise may offer a short window for vascular adaptation through the mobilisation of TANG cells into the circulation.

Migrant South Asian populations in Europe, North America the Westernised countries have a greater cardiovascular disease (CVD) risk than their respective indigenous populations. Both overall and premature CVD morbidity and mortality is significantly higher in migrant South Asians than in white populations in the UK and globally. Despite this, the role of ultrasound as a screening tool for CVD risk assessment in South Asians has not been studied extensively. Data also suggest that increased susceptibility to the adverse effects of insulin resistance and type 2 diabetes mellitus (T2DM) may contribute to the increased CVD risk. South Asians living in the United Kingdom also have a 3-5 fold increased prevalence of T2DM, developing the disease around a decade earlier and at a lower body mass index (BMI) compared to white Europeans. Furthermore, non-diabetic South Asians have higher fasting glycaemia and are more insulin resistant than Europeans. Liver fat is also associated with insulin resistance and T2DM risk and is considered to play a causal role in diabetes. Limited data suggest that South Asians have higher liver fat content than age- and BMI-matched Europeans, but it is not currently clear whether this contributes to the observed ethnic difference in insulin resistance. The first aim was to determine the extent to which increased insulin resistance and fasting glycaemia in South Asian, compared to white European men, living in the UK, was due to lower cardiorespiratory fitness (maximal oxygen uptake [VO2max]) and physical activity. The second aim was to determine whether South Asians have increased liver fat compared to Europeans and the extent to which any such differences can explain the increased insulin resistance observed between these groups. The final aim was to determine whether South Asians had a difference in carotid intima-media thickness (cIMT) or carotid plaque presence compared to Europeans; and if so, whether any measured risk factors (if any) could account for any such observed differences in cIMT and/or carotid plaque disease. 100 SA and 100 age and BMI-matched European men without diagnosed diabetes, aged 40-70 years, had fasting blood taken for glucose concentration, insulin, plus other risk factors, and underwent 2-dimensional carotid ultrasound for measurement of intima-media thickness and carotid plaque analysis, assessment of physical activity (using accelerometry), VO2max, body size and composition, and demographic and other lifestyle factors. For addressing the first aim of this thesis, 13 South Asian and 1 European man had HbA1c levels >6.5% indicating potential undiagnosed diabetes and were excluded from the analyses relating. Linear regression models were used to determine the extent to which body size and composition, fitness and physical activity variables explained differences in insulin resistance (assessed by Homeostasis Assessment Model of Insulin Resistance, HOMAIR) and fasting glucose between SA and Europeans. For the second aim, 28 South Asian and 24 European participants were chosen at random (but matched for age) within 4 months of their original main study visit to undergo magnetic resonance spectroscopy for quantification of liver fat. HOMAIR and fasting glucose were 67% (p<0.001) and 3% (p<0.018) higher, respectively, in South Asians than Europeans. Lower VO2max, lower physical activity and greater total adiposity in SA individually explained 68% (95% confidence interval [CI], 45-91%), 29% (95% CI, 11-46%) and 52% (95% CI, 30-80%), respectively, and together explained 83% (95% CI, 50-119%) (all p<0.001), of the ethnic difference in HOMAIR. Lower VO2max and greater total adiposity respectively explained 61% (95% CI, 9-111%) and 39% (95% CI; 9-76%) (combined effect 63% (95% CI 8-115%); all p<0.05)) of the ethnic difference in fasting glucose. Unadjusted mean liver fat content did not differ significantly between South Asians compared to Europeans (5.28 (standard deviation [SD], 2.11)% vs 5.41 (SD,2.35)%, p=0.913), but following adjustment for alcohol consumption was significantly lower in South Asians than Europeans (5.30 (SD, 2.10)% vs 9.03 (SD, 2.22)% p=0.017). Adjustment for alcohol-adjusted liver fat did not attenuate the difference in HOMAIR between ethnic groups. There were no significant differences in unadjusted or age-adjusted in mean cIMT between South Asians and Europeans. There was an increased odds ratio for the presence of plaque disease in South Asians compared to Europeans, however this was not significant (OR 1.57, 95% CI 0.89-2.77, p=0.13). Lower cardiorespiratory fitness is a key factor associated with the excess insulin resistance and fasting glycaemia in middle-aged South Asian compared to European men living in the UK. Also, whilst clear associations between liver fat and insulin resistance were observed in South Asians and Europeans, these results challenge the notion that excess liver fat per se explains the greater insulin resistance observed in South Asians. Finally, cIMT is similar between South Asian and European men and there is also currently no clear evidence for more carotid plaques in South Asian compared to European men living in the UK. This important negative finding highlights the need for further studies on carotid plaque or research in alternative screening methods for CVD which are more sensitive in identifying subclinical CVD.

The author of this thesis examines how SADS is made and remade within interdisciplinary professional practice. Whilst recent sociological scholarship has followed the discourse of ‘molecularization’ when examining the construction of biomedical categories, I instead place the genetic as part of a broader clinical and medico-legal system. Whilst it is accepted that there are genetic aspects of SADS this does not reduce the usefulness of other disciplinary explanations in practice. This thesis is situated around the molecular autopsy, a technology simultaneously employed to identify the cause of death and help in the diagnosis and treatment of family members of the deceased. As such, this thesis examines the professional system which surrounds this technology across the medico-legal – clinical divide. In doing so, the author of this thesis argues that the usefulness of genetic testing for SADS is an explicitly political problem. Suggesting that the current focus of research examining translational medicine falls short by focusing on the translation from ‘Bench to Bedside’, instead arguing for the importance of examining the political, and socio-economic space in which the technology is to reside. Finally, I explore the co-construction of the professional system of making SADS. A relational approach to professionalism is developed as a way to examine how mutuality is achieved during collaboration between distinct epistemic cultures. The consequence of such an approach is the ability to understand how professional groups are able to mobilise multiple conceptions of SADS in the pursuit of preventing future deaths. Making SADS gains further meaning in that I argue that understandings of SADS are distinct to accounts given in practice. Understandings of the usefulness of genetic testing for coroners is thus, not only based upon the ability of genetics to serve a particular function, but is based upon a fragmented account of the technology, rhetorically produced by clinicians.

China is facing epidemic of cardiovascular disease propelled by obesity, hypertension, dyslipidaemia, and hyperglycaemia. Epidemiological studies are continuing to show an increase in the prevalence of the aforementioned cardiovascular disease risk factors in the Chinese and studies are yet to shown signs of abating. Diet is able to affect the cardiovascular function by influencing the risk factors but very little is known about the diets of the Chinese. This thesis identified three dietary patterns (Non-nut and Non-cruciferous Vegetable, High Protein-High Fat, Omnivorous) using principal component factor analysis and examined the cross-sectional relationships with hyperglycaemia, hypertension, and metabolic syndrome in 20,146 middle-aged and older Chinese adults. The Non-nut and Non-cruciferous Vegetable diet was adversely associated with hyperglycaemia and the metabolic syndrome but showed no association with hypertension. The High Protein-High Fat diet was associated with reduced risk of hyperglycaemia and hypertension but exhibited no relationship with the metabolic syndrome. The Omnivorous diet was inversely associated with hyperglycaemia and the metabolic syndrome but demonstrated an adverse association with hypertension. In addition, the thesis developed a conceptual model and highlighted the putative mechanisms mediating the relationships between the High Protein-High Fat diet and cardiovascular disease risk factors using the structural equation model.