Proposal summaries
B3078 - Single SNP Replication of rs71564871 - 08/03/2018
A single mutation within the genome (called rs71564871 near a gene called BEND6) has been previously linked to fat distribution in the body, specifically the proportion of fat stored across the waist compared to the hips, in women of the ORCADES study and UK Biobank. Within this study, we want to assess whether this single mutation is similarly related to the same pattern of fat deposition in the Avon Longitudinal Study of Parents and Children.
B3081 - Helicobacter pylori - Association with cardiovascular disease and cancer - 13/03/2018
Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonises on the gastric epithelium, and there is clear evidence for its role in causing gastrointestinal diseases. Studies in the United Kingdom have demonstrated the prevalence of H. pylori infection status ranging from 26-66% of the population. There is increasing evidence of the role H. pylori in the development of other diseases, including cardiovascular disease and cancer. Given the relatively high prevalence of infection, this is potentially an important disease risk factor that merits causal investigation. Studies have suggested that infection with H. pylori may affect lipid metabolism, especially with the cardiovascular risk factors: HDL-cholesterol, triglyceride and apolipoproteins. By this mechanism, this could increase the risk of developing atherosclerosis and coronary artery disease. Additionally, studies have postulated that H. pylori could be involved in the development of atherosclerosis by causing vascular inflammation and endothelial dysfunction. H. pylori has also been shown to be involved in gastric carcinogenesis. Through the disruption of epithelial cell functions by H. pylori cytotoxin-associated antigen A (CagA), this oncogenic factor activates oncogenic pathways in these cells and induces epigenetic modifications which play a significant role in initiating carcinogenesis.
B3082 - Adaptations to Inequality and the Perpetuation of Disadvantages An Evolutionary Developmental Approach - 16/03/2018
Socioeconomic disparities in health across the life-course are well-documented, long-standing, and consequential. Research suggests that a significant proportion of the social gradient in health is due to SES differences in health-risk behaviors. Scholarship investigating the underlying mechanisms whereby lower SES increases health-risk behavior points to the mediating role of risk-increasing (or âriskogenicâ) psychosocial schemas. Specifically, evidence suggests that social context and experiences in development, which are patterned by oneâs social position, calibrate psychosocial orientations, including impulsivity or self-control, sensation seeking, and hostile views of relationships, which influence health-risk behaviors and health outcomes. Although the past decade has seen a spate of published GE-health research, few studies have focused on the role of G-E interplay in shaping psychosocial schemas as mechanisms through which SES adversity shapes health disparities. This project will investigate the effects of SES adversity on changes in psychosocial schemas, conceived as socially-calibrated and genetically-influenced endophenotypes which link SES adversity to increased health risk-behaviors. Additionally, although we know that social experiences âget under the skinâ to have enduring effects on health outcomes, we lack knowledge on the biological pathways through which such effects persist. Thus, second, and more innovatively, we will engage with the nascent field of social epigenetics to examine DNA methylation (DNAm) as a biological mechanism through which SES-adversity calibrates psychosocial schemas. In this project, we will investigate the DNAm patterns underlying psychosocial adaptations to SES adversity that increase health-risk behaviors, building on work that identifies DNAm as an important molecular underpinning of experience-dependent changes in cognitions, decision-making, and behavior.
B3083 - Exploring the relationship between bone turnover and serum levels of citrate - 16/03/2018
Osteoporosis is a metabolic disorder of bone, characterized by increased bone resorption. Serum collagen type 1 cross-linked C-telopeptide (CTX) is increased during bone resorption. In our preliminary metabolomic analysis, which aimed to identify the metabolic consequences of reduced bone turnover in a cohort of adults with high bone mineral density, we identified a positive relationship between serum CTX and NMR-assessed serum citrate levels (unpublished data). Citrate is a component of bone mineral with a potential structural function (Costello et al 2013). We aim to repeat our cross-sectional analysis of the association between serum CTX and serum citrate in both the ALSPAC mothers and adolescents population to determine if this association replicates, firstly in a general population cohort of a similar age, and secondly in a younger population, which would suggest that serum citrate is a novel marker of bone resorption.
B3005 - Hypertensive disorders of pregnancy and mental and behavioural disorders in offspring - 22/03/2018
There has been increasing research attention to the impact of in utero exposures to specific perinatal risk factors and their potential impact on diseases later in life. One of these is hypertensive disorders of pregnancy (HDP), a perinatal condition which affects up to 10% of pregnancies globally. Current evidence shows that HDP are associated with an increased risk of offspring cardiovascular, immune, metabolic disorders in later life. HDP are also responsible for various adverse perinatal outcomes such as preterm birth, low birth weight and intrauterine growth restriction, which are known risk factors for numerous mental health morbidities. In addition, HDP may also affect brain development via utero-placental vascular insufficiency and fetal malnutrition and lead to subsequent neurobehavioral difficulties. A lot of research has been conducted on the associations between HDP and cognitive functioning in offspring, however, evidence on the effect of intrauterine exposure to HDP on offspring mental and behavioural disorders is not well-established.
Two systematic reviews conducted by this team, one currently under review and the other one accepted by the British Journal of Psychiatry have shown that HDP had a negative impact for a range mental or behavioural disorders. Our finding showed that preeclampsia was associated with increased risk of offspring schizophrenia. The risk of Autism spectrum disorder was also 32% higher in offspring who had intrauterine exposure to preeclampsia as compared to those non-exposed. However, we found inconclusive finding on the effect of HDP and other mental and behavioural disorders, suggesting the need of further studies to progress this area of research. Following on from these findings, this PhD project aims to add to the existing evidence in a meaningful way by conducting a high quality, large sample, birth cohort study.
B3091 - Solids and formula feeding as risk factors for morbidity in infancy - 29/03/2018
A recent large scale evidence review has demonstrated the importance of exclusive breastfeeding to 6 months with partial breastfeeding continued though the first year of life, but few studies have considered whether starting solids earlier than 5-6 months, but with continued breastfeeding, increases the risk to health or causes earlier cessation of breastfeeding.
The review also found new evidence from the developing world that giving extra iron in children who are not short of iron may cause increased infections and slower growth. Formula milks which have higher iron content than either breast milk or doorstep milk are currently recommended from 6 months to 12 months where an infant is not breastfeeding to prevent iron deficiency anaemia and iron fortified follow on formulas are widely advertised. However the potential risks of iron supplemented formula milks have never been examined.
B3093 - Traits phenotypes and prognosis of childhood asthma - 29/03/2018
The proposal is to continue the collaborative work we have been doing with this Swiss group over the past few years. Ben Spycher was a Marie Curie Fellow who worked with ALSPAC data previously. Prof Kuehni leads eth Leicester Asthma Cohorts and has established the Swiss Paediatric Airway Cohort (SPAC). OUr joint objective is to discover influences that determine the onset and progression of asthma in children, how asthma varies between individuals in type and severity and whether we can predict the outcome of asthma using individuals' information. The data in eth Leicester adn Swiss cohorts is complementary to data held in ALSPAC and we have had joint publications where ALSPAC is able to replicate findings in the other cohorts run by the Swiss group.
B3088 - Metabolic profile of prediabetes using genetic susceptibility and repeat metabolomics to inform early detection - 29/03/2018
Type 2 diabetes develops for many years before it is diagnosed. Using data from ALSPAC offspring, we aim in this study to harness genetic susceptibility to adult type 2 diabetes and detailed metabolic profiling to better understand the early stages of diabetes development that are detectable in blood. This will involve describing associations of a genetic risk score comprised of hundreds of genetic variants for adult type 2 diabetes with hundreds of metabolic traits from targeted metabolomics at four key stages of early life â childhood (age 8y), adolescence (age 15y), early adulthood (age 18y), and formal adulthood (age 25y) â to view subtle changes in metabolism over time which precede the onset of clinical diabetes. Recognizing the early signs of diabetes is vital for early detection and for preventing downstream cardiovascular diseases and cancers.
B3087 - INTIMATE PARTNER VIOLENCE PERPETRATORS THE ORIGINS - 29/03/2018
Intimate Partner Violence (IPV) is defined as any violent behavior within an intimate relationship or any other controlling behavior that is conducted by a current or former partner. It is the most common form of violence in women which constitutes a major public health problem worldwide. The current explanatory theories of IPV perpetration can be summarized as feminist/sociocultural, social learning theory-based intergenerational transmission and psychological/psychosocial. According to the feminist/sociocultural theory, domestic violence is a consequence of âpatriarchyâ. From this view, violence is used as a form of power and control of women by men. The intergenerational transmission theory asserts that domestic violence is based on the exposure to, or observation of, violence in the family of origin. Psychological theories propose that there are psychological, psychiatric, behavioural and neurological risk factors for domestic violence perpetration. In the study of IPV perpetration, it is important to consider the variables addressed by such theories as a whole and from a developmental perspective and there is no study that simultaneously considers all the variables of these explanatory theories. The general aim of our study is to identify those etiological mechanisms linking risk factors for IPV perpetration across development. This study will be the first one that sheds light on which the origins of IPV perpetration are by knowing how IPV perpetration develops. Implications in terms of prevention and treatment will be of a great relevance for public health.
B3094 - A novel genetic instrument for lifetime smoking indicates that smoking is a causal risk factor for depression and schizophrenia - 04/04/2018
Smoking is highly co-morbid with several psychiatric conditions, but understanding the causal nature of this relationship is complicated by well-described issues of confounding and reverse causality. Mendelian randomisation uses genetic variants associated with an exposure (e.g., smoking) to examine causal pathways between the exposure and outcomes. Previous genetic instruments for smoking have only captured discrete aspects (e.g., initiation, heaviness of smoking), limiting power and requiring individual level data on smoking status for analyses of heaviness of smoking. To overcome these issues, we are developing a novel genetic instrument for comprehensive smoking exposure, which takes into account duration of smoking, heaviness of smoking, time since cessation, and a simulated half-life constant to capture the exponentially decreasing effect of smoking on health over time. Our instrument includes both smokers and non-smokers, removing the need to stratify on smoking status.
We have begun work on this instrument by conducting a genome-wide association study (GWAS) of our comprehensive smoking measure in the UK Biobank (N=463,003) and identified 124 independent SNPs associated at the genome-wide level of significance. Our two-sample Mendelian randomisation validation analysis confirmed that smoking causes lung cancer and coronary heart disease. To further establish the validity of the instrument we need to check that it predicts smoking in an independent sample. Here we hope to use ALSPAC, checking whether a polygenic risk score for lifetime smoking exposure predicts actual smoking behaviour. Secondly, we need to check that the instrument is not spuriously associated with any traits other than smoking. We can do this by checking for associations with other outcomes in ALSPAC.
If the instrument predicts smoking in ALSPAC and is not associated with other unexpected traits, we hope to go onto use our novel genetic instrument to explore bi-directional effects between smoking and mental health, focusing on schizophrenia and major depressive disorder.
B3092 - epigenetic heritability of child psychiatric phenotypes - 04/04/2018
Growing evidence points to a role of epigenetic alterations in the development of psychiatric disorders. DNA methylation â an epigenetic mechanism sensitive to both genetic and environmental influences â has been linked to a wide range of emotional and behavioral problems in childhood, including anxiety, depression, conduct problems and attention-deficit hyperactivity. However, findings to date have been primarily drawn from candidate gene studies, or EWAS studies investigating single sites across the genome. As a result, how much of the variance in psychiatric phenotypes is collectively explained by the methylome as a whole is currently unknown.
B3090 - Epigenetics in peer victimization and behavioural and emotional development - 05/04/2018
Peer victimization is a widespread phenomenon with many harmful and persistent consequences, such as anxiety, depression, and even suicidal ideation. However, consequences of can vary widely in presentation and severity, which hinders development of appropriate interventions targeted at alleviating the effects of peer victimization. This may in part stem from the fact that little is known about the biological mechanism through which bullying affects children's psychological development and wellbeing. Therefore, we aim to study how peer victimization is related to epigenetic development and explore to what extent epigenetics mediate the association between peer victimization and negative outcomes in children. We will do this by combining data of two large comparable cohorts, ALSPAC in England and Generation R in Holland.
B3095 - Genome-wide association analysis of voting behaviour for Mendelian randomization - 11/04/2018
Genome-wide association studies (GWAS) have been critical in identifying thousands of genetic variants associated with complex traits and diseases. For certain complex traits however, it may be the case that there is difficulty in phenotypic measurement and this can lead to issues of statistical power. This is particularly problematic for behavioural phenotypes that may be predominantly determined by the environment, as is the case for educational attainment and well-being (Okbay et al., 2016; Okbay et al., 2016; Rietveld et al., 2013). Genetic analyses of such phenotypes can be hindered by the fact that individual SNPs have limited explanatory power and any associations found may not be causal or may be mediated by many other intermediate phenotypes (Krapohl et al., 2014). However, such studies have enabled the description of common genetic contributions to complex behaviours. Taken together, these GWAS results form a pool of genetic variants which may then be used in Mendelian randomization (MR) analyses; both looking at the effect of these features on outcomes but also the effect of outcomes on them.
This project will use newly collected data in the Avon Longitudinal Study of Parents and Children cohort to analyse voting behaviour. Firstly, we aim to conduct a GWAS on voting behaviour to discover any genetic variants associated with this complex trait. Additionally, we plan on considering the potential of using MR analysis to look at this behavioural phenotype. Specifically, we aim look at the effect of well instrumented risk factors on voting behaviour itself, i.e. âbackwards MRâ.
References
Krapohl, E. et al. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. Proc. Natl Acad. Sci. USA 111, 15273â15278 (2014).
Okbay, A. et al. Genetic variants associated with subjective well-being, depressive symptoms, and neuroticism identified through genome-wide analyses (vol 48, pg 624, 2016). Nature Genetics 48, 1591-1591 (2016).
Okbay, A. et al. Genome-wide association study identifies 74 loci associated with educational attainment. Nature 533, 539-+ (2016).
Rietveld, C.A. et al. GWAS of 126,559 Individuals Identifies Genetic Variants Associated with Educational Attainment. Science 340, 1467-1471 (2013).
B3096 - Does cognitive vulnerability modify the association between stressful life events and future depression - 11/04/2018
Several studies have found that the experience of stressful life events (ranging from more severe events, such as divorce or bereavement, to daily hassles, such as family-related obligations) can lead to symptoms of depression. However, the impact of these events varies, and not everyone who experiences a stressful event goes on to experience depression. Weâre interested in studying whether cognitive vulnerability, the tendency to make negative causal inferences about an event, can explain this difference (i.e., is an effect modifier). That is, the interpretation of the event, rather than exposure to the event alone, may be particularly important for predicting future depression. This study aims to investigate how the impact of stressful events varies between people, and why certain people go on to experience depression while others do not. These findings could inform potential targets for interventions which intend to prevent depressive symptoms.
B3097 - A meta-analysis of maternal smoking GFI1-CpGs and cardio-metabolic phenotypes in adults - 17/04/2018
Individuals exposed prenatally to cigarette smoke tend to have lower birthweight and have higher risks for a variety of detrimental health outcomes later in life. Cigarette smoke exposure is also associated with DNA methylation changes at gene GFI1, and recent evidence suggests that these changes may play a role in the lower birthweight of exposed infants. We would like to determine if there is evidence that these DNA methylation changes may also play a role in risk factors for other health outcomes of prenatal cigarette smoke exposure. We would specifically like to investigate factors related to cardiovascular and metabolic health.
B3099 - Lung function growth and residential greenness in the ALSPAC cohort - 19/04/2018
There is increasing evidence that residential greenspaces (proximity to and amount of green spaces and vegetation around a person's home) may be associated with various health outcomes, including increased physical activity levels and respiratory health outcomes, such as asthma. As lung function is associated with both physical activity and asthma, it could thus also be associated with greenspaces. However, to date, no study has examined whether an association between residential greenspaces and lung function exists in children, and what potential pathways may be playing an important role. Using the ALSPAC data, this study aims to fill this research gap.
B3104 - Impact of Breastfeeding on Cardiovascular and Metabolic Outcomes in Women with a History of Hypertensive Disorders of Pregnancy - 26/04/2018
Women who experience a hypertensive disorder of pregnancy are at greater risk for diseases of the heart and blood vessels. Breastfeeding may reduce this risk in women in general and particularly in those who have had a hypertensive disorder of pregnancy. This proposed study will examine if the duration/amount of breastfeeding has a beneficial effect on markers of heart health in later life in women who did and did not develop a hypertensive disorder of pregnancy.
B3106 - Does the effect of eating patterns at night on childhood weight status differ between the UK and China - 08/05/2018
It has been suggested that night eating is related to increased fat storage and therefore increased body weight. There is also no clear definition of what is meant by night eating. The potential effects of night eating on obesity have primarily been examined in adults to date and any studies in childhood have been cross-sectional, with none in the UK. Based on information collected in diet diaries at the age of 7, this project will aim to examine different definitions of night eating and examine the effects on childhood weight status and it's change over time. This will be carried in two different cohort studies - one based in the UK and one based in China.
B3108 - Longitudinal patterns and predictors of multiple cancer-risk behaviours among UK adolescents - 08/05/2018
Using two British cohort studies, the Avon Longitudinal Study of Parents and Children (ALSPAC) and the Millennium Cohort Study (MCS), this fellowship will explore the longitudinal patterns and predictors of multiple cancer-risk behaviours (MCRB). MCRB are modifiable behaviours including tobacco smoking, alcohol consumption, physical inactivity, overweight and obesity, unhealthy diet and risky sexual behaviour that are associated with cancer incidence and mortality. Rather than focusing on specific cancers this research will cover a wide range of cancers that are associated with these behaviours.
B3111 - Time-dependent associations between body mass/body composition physical activity diet and lung function in childhood - 08/05/2018
The large increase in the prevalence of respiratory diseases over the last decades, in the West more particularly, cannot be explained by genetics only. It has been hypothesized that these increases are a consequence of changing environmental and/or lifestyle factors. Given the multifactorial aspect of these diseases, it is thus important to take into account the interrelations between these factors and respiratory health. The interrelations between body mass/body composition, physical activity, diet and lung function in childhood and adulthood have been incompletely addressed, likely because their time-dependent and bidirectional nature represent a methodologically challenging research question. Marginal structural models (MSMs) allow estimation of causal effects in observational studies by addressing time-dependent confounding (Robins JM et al. Epidemiology 2000). This approach has still limited application in respiratory epidemiology. We aim to investigate the joint and independent causal effects of body mass/body composition, physical activity and diet on lung function during childhood and early adulthood using MSMs in children from the ALSPAC study.