The prevalence of type 2 diabetes is increasing in the UK. Many people with type 2 diabetes require glucose-lowering therapy including insulin when lifestyle interventions fail to provide adequate glucose control. Some epidemiological studies report an association between insulin use in type 2 diabetes and an increased risk of serious adverse events when compared with other glucose-lowering therapies. However, these findings should be interpreted with caution due to the risk of confounding by indication. The aim of this thesis was to characterise the epidemiology of type 2 diabetes and to investigate the risk of serious adverse events associated with increasing insulin dose in people with type 2 diabetes prescribed insulin therapy. A series of retrospective, observational studies were conducted using data from the Clinical Practice Research Datalink. People with type 2 diabetes were identified and prevalence and incidence rates calculated. The risk of all-cause mortality, major cardiovascular events and cancer in people with type 2 diabetes who progressed to insulin with or without metformin were evaluated using multivariate models. Between 1991 and 2010, the estimated incidence and prevalence of clinically diagnosed and recorded type 2 diabetes increased three-fold. During the same period, the estimated number of people with diagnosed and recorded type 2 diabetes treated with insulin increased seven-fold. Estimated insulin dose was associated with an increased risk of all-cause mortality in people with type 2 diabetes receiving insulin monotherapy (aHR 1.54, 95% CI 1.32–1.78, for 1 unit/kg/day increase in insulin dose) and in those treated with insulin with or without metformin (1.48, 1.31–1.70). However, the use of metformin in combination with insulin was associated with a reduction in risk compared with insulin alone (0.60, 0.52–0.68). Due to the limitations associated with observational studies, further research is required in order to improve our understanding of the risks and benefits of exogenous insulin in type 2 diabetes.

Background: The HOPE trial showed that ramipril reduced cardiovascular morbidity and mortality in patients with peripheral arterial disease (PAD). However, evidence regarding the effect of angiotensin converting enzyme (ACE) inhibitors on walking distance, ankle brachial pressure index (ABPI), arterial stiffness and quality of life (QoL) in this group of patients is limited. Objective: The aim of this study is to investigate ACE inhibitors effect on clinical parameters of PAD, arterial stiffness and QoL in patients with intermittent claudication (IC). Methods: 33 patients (25 males, mean age: 65+/-7.8) with IC (Fontaine stage II or higher) were randomised to receive ramipril (5 mg once daily for 2 weeks increased to 10 mg once daily for 22 weeks, n=14) or placebo (n=19) for 24 weeks in a double-blind study. Walking distance was assessed using a standard laboratory treadmill test (2.5 km/hr at 10% incline). ABPI was assessed pre (r-ABPI) and post-exercise (t-ABPI). Arterial stiffness indices were measured using the SphygmoCor device. Results: After 24 weeks, ramipril improved maximum treadmill walking distance; adjusted mean change difference (95% confidence interval); by 130.5 (61.8 to 199.2) m longer than placebo (P=0.001), improved treadmill intermittent claudication distance by 121.9 (55.9 to 187.8) m longer than placebo (P=0.001) and improved patient reported walking distance by 159 (5.5 to 313) m compared to placebo (P=0.040). Ramipril reduced carotid femoral pulse wave velocity (a measure of arterial stiffness) by -1.47 (-2.4 to -0.57) m/s compared to placebo (P=0.002). However, r-ABPI and t-ABPI minimally changed in both groups (Ramipril 0.02 (-0.08 to 0.11)) vs. placebo 0.03 (-0.05 to 0.10, P=0.830) and (Ramipril 0.04 (-0.04 to 0.12)) vs. placebo 0.02 (-0.04 to 0.09, P=0.720), respectively. Ramipril had a slight insignificant effect on QoL physical domains compared to placebo. Conclusion: Ramipril improves walking distance in patients with IC; however, this improvement is not related to improvement in ABPI but might be due to ramipril ability to reduce arterial stiffness. ACE inhibitors effect on QoL needs to be validated in a larger randomised controlled trial.

This mixed method research study originally contributes to understand the role covered by Supported Employment Agencies (SEAs) in promoting positive health behaviours of employees with learning disabilities. Employment is rarely experienced by people with learning disabilities. Supported Employment Agencies provide a service to facilitate the employment experience for people with learning disabilities, through supporting in finding, keeping and maintaining a job. While many studies on employment have highlighted health benefits for the general population in employment, data is lacking for people with learning disabilities. This study wants to understand if and how Supported Employment Agencies support the health of their clients with learning disabilities. The quantitative phase of this study involved managers of Supported Employment Agencies completing a web-survey to understand the strategies used by Supported Employment Agencies preventing health risk behaviours and promoting health. In the qualitative phase of this study Grounded Theory Method was used to discover the role played by Supported Employment Agencies in supporting the health of their clients with learning disabilities. For this purpose interviews with mangers and job coaches of Supported Employment Agencies and interviews with employees with learning disabilities were held. Results from this study reveal Supported Employment Agencies to influence the health of employees with learning disabilities in several ways, both informally and formally. Indeed, health was a key element in all phases of supported employment, even if Supported Employment Agencies were not formally committed and funded to promote health. The thesis highlights the potential for SEAs to capitalise on their role as employment mediators to promote health outcomes and healthy lifestyles for employees with learning disabilities.

This thesis was an observational study to retrospectively examine the prevalence and incidence of DR and its associated risk factors from two screening services (Wales and Johannesburg, South Africa) in order to determine safe screening intervals in persons without evidence of DR at initial screening based on digital photography. Between 2005 and 2009 a total of 135,152 persons with diabetes over 12 years of age in Wales were screened. However, a total of 43,759 persons were excluded from analysis as they did not have their type of diabetes recorded (29,807) or where it was recorded it was outside of the pre-specified age at diagnosis of diabetes range of ≥30 years for type 2 DM and <30 years for type 1 DM (13,952). In the Centre for Diabetes and Endocrinology, Johannesburg, South Africa a smaller population of 5,565 were screened between 2001-2010. A total of 50 persons were excluded from this analysis as they had a type of diabetes recorded other than type 1 DM or type 2 DM. Therefore, data from 91,393 (86,390 T2DM, 5,003 T1DM) persons from the Wales screening service and 5,515 (3,978 T2DM, 1,537 T1DM from South Africa, were analysed. In Wales, the prevalence of any DR was 31.0%, background DR (BDR) 26.6% and referable DR (RDR) 4.4% in T2DM at baseline. The prevalence was higher in T1DM at 56.2%, 39.8% and 16.4% respectively. Increased duration of diabetes was independently associated with increased prevalence and incidence of any DR, BDR and RDR for T2DM and T1DM as well as treatment modality in T2DM. The four year cumulative incidence of RDR was 1.6% for T2DM and 5.6% for T1DM. At the Centre for Diabetes and Endocrinology Johannesburg the prevalence of any DR was 21.6%, BDR 14.8% and RDR 6.7% in T2DM at first screening and higher at 36.9%, 27.2% and 9.7% respectively for T1DM. Glycaemic control (HbA1c) and duration of diabetes were significantly associated with the prevalence and incidence of any DR, BDR and RDR in both T2DM and T1DM. Ethnicity and hypertension were also risk factors. The seven year cumulative incidence of RDR was 4.7% for T2DM and 5.0% for T1DM. Risk factor analysis indicated that the screening intervals could be extended beyond annual based on type of diabetes, duration of diabetes, HbA1c, ethnicity, hypertension and treatment modality in T2DM. This analysis adds to an increasing evidence base for considering extending the screening intervals beyond annually for those at low risk with no DR at initial screening. Limitations of this study included the need to exclude a high number of persons in order to ensure the quality of the data; the numbers lost to follow up (meaning all results from 3 years should be interpreted with caution) and the fact that the visual impairment and blindness within the programmes could not necessarily all be attributed to DR as recordings of other lesions were not included in the datasets.

The individual, familial, societal and economic impact of psychological distress following stroke is well established. Nevertheless, validated treatments to reduce psychological distress and enhance well-being in community-living stroke survivors is limited. Recently, Acceptance and Commitment Therapy (ACT) has demonstrated promising results for improving psychological wellbeing in a variety of presentations. However, there is a lack of research exploring ACT with adults who have survived a stroke. The current thesis examines the efficacy of a four-session ACT intervention that was delivered to both stroke survivors and their carers via a third-sector charity organisation. A quasi-experimental design was used with 69 participants assigned to either the ACT intervention or waiting list control group. Outcome variables captured levels of psychological distress, post-traumatic growth and quality of life at three time points (pre-intervention, post-intervention and two month follow-up) and were analysed using linear regression whilst controlling for baseline levels. A mediational analysis examining specific ACT processes – psychological flexibility and goal directed thinking - were also examined. Additionally, a one-hour focus group including seven individuals who completed the group was analysed by inductive thematic analysis to gain greater insight in to the personal experiences of the group. Group assignment predicted lower psychological distress in favour of the ACT group at post-intervention and at follow-up. There were no significant differences found for post-traumatic growth or quality of life. The mediational analyses suggest that the ACT intervention did not significantly alter levels of psychological flexibility, or goal directed thinking compared to the waiting list control group, and these measures did not appear to mediate the changes in psychological distress. The qualitative analysis supported the positive gains of the ACT group. The results are discussed in terms of developing ACT intervention for stroke survivors and carers.

Bleeding following cardiac surgery requiring cardiopulmonary bypass (CPB) is associated with increased morbidity. Identification of patients at increased risk of bleeding might allow intervention to prevent bleeding developing. In this thesis, clotting factors, anticoagulants and calibrated automated thrombin generation were investigated as potential methods for identifying such patients. Post-CPB FXIII, fibrinogen and platelet count were significantly lower in those who bleed more than 2 mL/kg/hr for two consecutive hours and in those who bleed in excess of 1 litre at 24 hours. ROC analysis demonstrated these had modest predictive value. Calibrated automated thrombography was unable to identify patients at risk of bleeding. Calibrated automated thrombography was also used to investigate the effects of haemostatic treatment (FFP, rFVIIa, PCC and TFPI inhibition) on thrombin generation in vitro. Blocking the effect of TFPI produced the greatest improvement in thrombin generation. The effect of CPB on platelet phospholipids was investigated using mass spectrometry. Post-CPB the ability to externalise phosphatidylethanolamine and phosphatidylserine was impaired. The ability to externalise and synthesise 12-HETE-PC and 12-HETE-PE in response to both thrombin and collagen post-CPB was also reduced. The effect of these phospholipids on thrombin generation and the ability to identify patients at risk of bleeding was then investigated. Thrombin generation using liposomes containing 12-HETE-PC or 12-HETE was lower in patients who required haemostatic treatment for post-CPB bleeding compared to those who did not. This suggests there are variations between individuals in the way their coagulation factors interact with oxidised phospholipids and that this may influence bleeding. Finally a cell based model of thrombin generation was developed using monocytes as a source of tissue factor and incorporating the observed changes in phospholipids, clotting factors and anticoagulants. This model provides a basis to further investigate the influence of different TF expressing cells on thrombin generation which may affect bleeding.

Hirschsprung’s disease causes a life-threatening bowel obstruction in children shortly after birth, because the stem cells that will form the enteric nervous system (ENS) have failed to colonise the entire length of the gut, creating an absence of neuronal cell bodies – the aganglionic region. Although there are numerous surgical techniques to deal with this problem, many children go on to have severe problems with constipation and faecal incontinence, and some require a permanent colostomy. It was hypothesised that clinical outcomes in children with Hirschsprung’s disease could be improved by transplanting ENS stem cells into the defective bowel, as previous studies has already shown it was possible to produce such stem cells from embryonic bowel . The aim of this thesis was to develop a method of isolating such cells from the bowel of children with and without Hirschsprung’s disease, characterise these cells and investigate whether they could be successfully transplanted in an in vitro model. In the first part of this thesis, a method was developed to take samples of postnatal bowel (both small and large) and dissociate it to produce a cell suspension that will allow ENS stem (or progenitor) cells to grow in the form of neurospheres. These neurospheres are characterised in terms of growth and composition, and it is shown that they contain reproducing cells that are capable of forming neurons on subsequent differentiation. When the neurospheres are transplanted into aganglionic embryonic mouse bowel grown in tissue culture, neurons and glia from the neurosphere colonise the bowel wall. In the second part of this thesis, the neurospheres were further characterised in terms of their response to the ENS growth factors glial cell derived neurotrophic factor (GDNF) and endothelin 3 (EDN3) and this was compared to the response of neurospheres derived from embryonic and neonatal mice. It was shown that postnatal human ENS neurospheres require the addition of GDNF to produce significant neurite outgrowth. Subsequent studies then demonstrated that the human neurospheres could be dissociated and regrown in culture, exponentially increasing their numbers whilst retaining the ability to produce neurons and glia on transplantation into aganglionic embryonic hindgut. In the final part of this thesis the functional effect of neurosphere transplantation into aganglionic embryonic hindgut was investigated. Firstly it was shown that the transplanted neurons integrate closely with the recipient smooth muscle and gut pacemaker cells (the interstitial cells of Cajal). Secondly it was shown that aganglionic embryonic mouse hindgut has a higher rate of contraction than ganglionic bowel cultured in the same conditions, and that human and mouse ENS neurosphere transplantation restores the contraction frequency of aganglionic bowel to that of ganglionic bowel. Taken together the results presented in this thesis demonstrate that it is possible to generate neurospheres from postnatal human bowel samples that contain ENS stem cells which are capable of producing a restorative functional effect when transplanted into an in vitro model of Hirschsprung’s disease. This is a step toward the development of a successful stem cell treatment for this condition.

Background: The practice of palliative care and the specialty of palliative medicine emerged from the modern hospice movement and its foundational philosophy of treating the whole person. This holistic approach recognises that the needs of dying patients are complex and multifaceted. Spirituality is one of the dimensions of palliative care practice and it was assumed that there was sufficient robust primary data to support a synthesis of evidence. However, a critical examination of the published data found that many studies make use of unexamined assumptions and ambiguous constructs. The research in this field is therefore missing an important methodological step in the inductive cycle by failing to articulate explicit theory or identify critical concepts. Aim: To construct a conceptual model of spirituality that provides a systematic way of illustrating the essential properties, functions and relationships of how spirituality operates in the lives of palliative care patients that can be subject to empirical testing. Methods: Conceptual model building was used as a method of theoretical investigation to construct a minimal abstract and indirect representation of the way that spirituality potentially operates in the lives of patients. The model was then subject to empirical testing through generating quantitative and qualitative data from palliative care patients participating in a questionnaire and interview. Analysis: Quantitative data from the questionnaires was subject to descriptive statistics and exploratory data analysis using techniques of visual representation. Qualitative data was subject to deductive content analysis based upon categories derived from the conceptual model. Results: A Synoptic Model was developed whose theoretical claims were congruent with the findings from this sample with the exception of the disease construct. 19 patients participated in the questionnaire phase of the study and 10 participated in an interview. Patients discussed multiple aspects of spirituality including their beliefs, practices and experiences. For some patients spirituality provided an orientation to life and helped make sense of illness and its consequences. Spirituality was also a resource for some patients in helping them to face their current situation and their mortality. Discussion: The Synoptic Model provides empirically supported theoretical knowledge of spirituality that can be utilised in the context of palliative care and has implications for clinical practice in terms of patient care, education and development, and assessment. Further development and testing is required in different settings to refine the Synoptic Model’s content and specification.

Aims: To measure symptomatic recovery over a year among an adult cohort recruited from hospital with community acquired pneumonia (CAP). To measure the host recovery mechanism efferocytosis and the diversity of the bacterial microbiota in sputum and relate these to individual characteristics of subjects in the cohort. Methods: Patients with CAP were recruited from two hospitals in Liverpool, (UK) and were followed-up for one year. The CAP-sym questionnaire was completed at multiple time-points in order to create a statistical model of symptomatic recovery. DNA was extracted from acute sputum samples and 16S rRNA sequencing revealed the diversity of bacteria in sputum. At one month into recovery subjects volunteered for bronchoalveolar lavage and rates of efferocytosis were measured by co-culturing ex-vivo alveolar macrophages with apoptotic autologous neutrophils. Results: The 169 subjects recruited with CAP were found to have high levels of socio-economic deprivation, smoking and COPD and the median age was 64 years. A non-linear, longitudinal, statistical model of symptoms found that smoking impaired recovery but people tended to describe better recovery as they got older. Efferocytosis was impaired by smoking but improved by statins and these effects were modified by body mass index. Those with prior pulmonary disease had lower bacterial diversity in their sputum and in this cohort a species from the genus Haemophilus was dominant. Conclusion: This work proves the principal that modelling CAP-sym scores can be used to investigate factors associated with differential recovery from CAP. It highlights the detrimental effects of smoking on both recovery and efferocytosis. This is the first study to show that the bacterial diversity of CAP sputum is influenced by prior lung disease. The translational outcomes are the potential for trials of statins as pro-recovery agents and to study modified empirical antibiotics for those with CAP and prior-lung disease.

Background: Systemic sclerosis (SSc) is a disease characterised by a triad of immunological abnormalities, endothelial cell dysfunction and fibrosis. Neutrophils are the most abundant circulating leukocyte. They contain several mediators which when released can lead to modulation of the inflammatory response, cause endothelial cell activation and injury and eventually lead to fibrosis. The peri-endothelial cell environment in SSc has the potential to lead to neutrophil activation and indeed this has been previously described in the literature in terms of reactive oxygen species (ROS) generation. In this thesis I aim to explore the hypothesis that: “Neutrophils are activated in SSc and contribute to endothelial cell activation and damage”. Methods: The functional phenotype of SSc neutrophils was explored in vitro. Functions investigated included; ROS generation, chemotaxis, integrin expression, apoptosis and CD16 expression. The protein expression of ex vivo SSc neutrophils was compared to healthy control neutrophils. The DIGE technology was used to explore the pan-proteome and iTRAQ was used to focus in on the plasma membrane proteome. The role of neutrophil elastase was explored in SSc by examining the serum neutrophil elastase concentration and activity and correlating these to clinical manifestations of disease. The role of neutrophil: endothelial cell interactions was modelled in vitro using live cell imaging by confocal microscopy looking for evidence of endothelial cell activation (E-selectin expression) and apoptosis. Experiments examined the role of neutrophil derived mediators in these interactions. Results: Functional studies revealed that SSc neutrophils are hypofunctional in terms of spontaneous ROS generation and chemotaxis in vitro. This may reflect in vivo activation. SSc neutrophils are similar in terms of integrin expression and baseline apoptosis to control neutrophils. Pan-proteomic studies reveal neutrophil activation in SSc since changes in protein expression mirror those seen in response to neutrophil activators TNFα and LPS. Proteomic studies also point to neutrophil priming in vivo. Serum neutrophil elastase concentrations and activity were not elevated in SSc, however, discrepancies between concentration and activity suggest a functional deficiency in elastase inhibitors in SSc serum. Serum elastase activity and concentrations were found to be lower in RNP (ribonucleoprotein) positive patients indicating that different mechanisms maybe involved in different SSc subtypes. In vitro models demonstrate that SSc serum causes endothelial cell activation and apoptosis and that neutrophils are essential for this effect. Serine proteases seem to play an important role in inducing apoptosis and IL-6 trans signalling is involved in endothelial cell activation and apoptosis. Neutrophils do not express IL-6 but are dominant sources of the soluble IL-6R which is essential for trans signalling. Conclusions: There is evidence that neutrophils are activated in SSc though; no specific activating signature is identified. In co-cultures, neutrophils are essential for endothelial cell activation and apoptosis in response to SSc serum. Neutrophil mediators including serine proteases and IL6R are likely to play important roles in this effect. Therefore neutrophils may play an important part in the propagation of inflammation and endothelial cell activation which eventually leads to the fibrotic phenotype which is characteristic of this disease.