Psychosocial and biological determinants of ill health in relation to deprivation

Background: Despite public health campaigns and improvements in healthcare, socioeconomic gradients in health and life expectancy persist, and in many cases are becoming more marked – the gradient in coronary heart disease being a prime example. Classic cardiovascular risk factors (e.g. smoking, cholesterol and blood pressure) only partially explain the deprivation effect, and attempts to narrow the health gap by focussing on such risk factors do not appear to be succeeding. There also appear to be socioeconomic differences in uptake of healthy lifestyle advice. The work described in this thesis aimed to expand current understanding of the deprivation-based gap in health and life expectancy, focussing particularly on the socioeconomic gradient in cardiovascular risk. Methods: Using a cross-sectional, population-based study design based in the Greater Glasgow area, 666 participants were selected on the basis of area-level social deprivation (Scottish Index for Multiple Deprivation ranking). The study was designed to include approximately equal numbers from most deprived and least deprived areas; equal numbers of male and female participants and equal numbers of participants from each age group studied (35-44; 45-54 and 55-64 years). Participants completed an extensive questionnaire on health, lifestyle and early life experiences. Anthropometric measures (height, leg length, weight, waist, hip and thigh circumferences) were recorded. Blood pressure, heart rate and parameters of lung function (Forced Expiratory Volume in 1 second [FEV1] and Forced Vital Capacity [FVC]) were recorded. Psychological assessments (General Health Questionnaire-28, Generalised Self-Efficacy Scale, Sense of Coherence Scale, Beck Hopelessness Scale, Eysenck Personality Scale and Rosenberg Self-Esteem Scale) and assessments of cognitive function (Auditory Verbal Learning Test, Choice Reaction Time and Stroop Test) were undertaken. Fasting blood samples were obtained for classic and emerging cardiovascular risk factors including lipid profile, glucose, insulin, leptin, adiponectin, C-reactive protein, interleukin-6, soluble intercellular adhesion molecule-1, von Willebrand Factor, fibrinogen, D-dimer and tissue plasminogen activator antigen. Carotid ultrasound assessment of intima-media thickness (cIMT), plaque score and arterial stiffness was performed. Results: Total and low density lipoprotein cholesterol were significantly higher in the least deprived group (both p<0.0001). Triglycerides were higher and high density lipoprotein cholesterol lower in the most deprived group (both p<0.0001). Fasting glucose, insulin and leptin were higher in the most deprived group. C-reactive protein, interleukin-6 and soluble intercellular adhesion molecule-1 were higher in the most deprived group (all p<0.0001). Von Willebrand factor, fibrinogen and D-dimer were higher in the most deprived group. Age- and sex-adjusted cIMT was significantly higher in the most deprived group, but on subgroup analysis this difference was only apparent in the highest age tertile in males (>56.3 years). Plaque score showed a much more highly significant deprivation difference in the group as a whole (p<0.0001). No differences in parameters of arterial stiffness were found between the most deprived and least deprived groups. Neither adjustment for classic nor emerging cardiovascular risk factors, either alone or in combination, abolished the area-level deprivation-based difference in plaque presence or cIMT. Adjustment for early life markers of socioeconomic status in addition to classic cardiovascular risk factors abolished the deprivation-based difference in plaque presence. Further associations between early life factors and health outcomes were noted: lung function (FEV1) and cognitive performance appeared to be influenced by father’s occupation, whether the parents/guardians were owner-occupiers or tenants, and by degree of overcrowding; cIMT was modestly related to father’s occupation and carotid plaque was related strongly to father’s occupation and parental home status. Socioeconomic differences were noted in the impact of personality in determining mental wellbeing, and also in relation to the health behaviours of fruit and vegetable consumption and smoking cessation. Conclusions: The relationship between social deprivation and health is complex and multifactorial and appears to involve the interplay of early life factors, biological mediators, psychological parameters such as personality and cognitive function, health behaviours and outcomes such as atherosclerosis. Approaches aiming to narrow the deprivation gap in health will need to be designed to take into account this complexity, addressing factors such as early life experiences and personality, as well as the more classically recognised factors such as smoking, cholesterol and blood pressure, if they are to have a chance of succeeding in improving the health of those most in need.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Viral production in the Gulf of Trieste (Northern Adriatic Sea): preliminary results using different methodological approaches.

Although the temporal and spatial variability of virioplankton in the northernmost part of the Adriatic Sea has been repeatedly explored suggesting that viruses constitute an extremely dynamic component of the plankton community and hypothesizing their importance in marine food webs and mucilage events, there is still no information about viral replication rates. Hence, the contribution of viruses to bacterial mortality and the cycling of organic matter in this part of the Adriatic basin are still not fully comprehended. Assessment of the role of viral lysis requires a robust means of estimating viral production. Since, up to now, none of the available methods evolved to a state of a standard yet, in this preliminary study 3 different experimental approaches were simultaneously assayed (viral production estimated by radiotracer incorporation method [TdR], dilution technique for the estimate of viral production in already infected bacteria [DIL] and serial dilution method in manipulated phage-host assemblage [SER]). The present study provided the first evidence of viral production rates in this study area, that resulted in comprising between 3c3.5\u201315 7108 viruses L 121 h 121 and critically faced up the results obtained by different techniques with the consideration that they suffer from different biases. Based on TdR and DIL viral proliferation estimates, viral lysis was responsible for the loss of 54 to 95% of the bacterial standing stock, while the viral-induced mortality by SER (325%d 121) was likely consistently overestimated. These results indicate that viral lysis is a significant factor for prokaryotic mortality suggesting its implication as an important pathway for the cycling of dissolved organic matter in the Gulf of Trieste

Large-scale spatial distribution of virioplankton in the adriatic sea: Testing the trophic state control hypothesis

Little is known concerning environmental factors that may control the distribution of virioplankton on large spatial scales. In previous studies workers reported high viral levels in eutrophic systems and suggested that the trophic state is a possible driving force controlling the spatial distribution of viruses. In order to test this hypothesis, we determined the distribution of viral abundance and bacterial abundance and the virus-to-bacterium ratio in a wide area covering the entire Adriatic basin (Mediterranean Sea). To gather additional information on factors controlling viral distribution on a large scale, functional microbial parameters (exoenzymatic activities, bacterial production and turnover) were related to trophic gradients. At large spatial scales, viral distribution was independent of autotrophic biomass and all other environmental parameters. We concluded that in contrast to what was previously hypothesized, changing trophic conditions do not directly affect virioplankton distribution. Since virus distribution was coupled with bacterial turnover times, our results suggest that viral abundance depends on bacterial activity and on host cell abundance