The ‘Blood-Type’ diet advises individuals to eat according to their ABO blood group to optimize health without the support of science evidence. The objective of this study was to determine whether consumption of a diet in accordance with an individual’s ABO genotype is associated with various biomarkers of cardiometabolic health. Study subjects (n=1,455) were participants of the Toronto Nutrigenomics and Health study. Dietary intake was assessed using a one-month, 196-item food frequency questionnaire and a diet score was calculated to determine relative adherence to each of the four blood type diets. ABO blood group was determined by genotyping rs8176719 and rs8176746 in the ABO gene. The results show that adherence to the Type-A, Type-AB, and Type-O diets were associated with favourable profile of certain cardiometabolic risk factors (P<0.05); however, these dietary effects were not dependent on someone’s ABO blood group. Therefore, the findings do not support the “Blood-Type” diet hypothesis

The ‘Blood-Type’ diet advises individuals to eat according to their ABO blood group to optimize health without the support of science evidence. The objective of this study was to determine whether consumption of a diet in accordance with an individual’s ABO genotype is associated with various biomarkers of cardiometabolic health. Study subjects (n=1,455) were participants of the Toronto Nutrigenomics and Health study. Dietary intake was assessed using a one-month, 196-item food frequency questionnaire and a diet score was calculated to determine relative adherence to each of the four blood type diets. ABO blood group was determined by genotyping rs8176719 and rs8176746 in the ABO gene. The results show that adherence to the Type-A, Type-AB, and Type-O diets were associated with favourable profile of certain cardiometabolic risk factors (P<0.05); however, these dietary effects were not dependent on someone’s ABO blood group. Therefore, the findings do not support the “Blood-Type” diet hypothesis

BACKGROUND: There are many studies that have documented the increasing impact of stress and anxiety on an individual’s health and well-being. Everyone handles stress and anxiety differently with these conditions having varying physiological effects. To better recognize whether or not a person may need help in tackling these conditions, scholars have developed reliable validated instruments. Two prominent instruments that effectively assess stress and anxiety levels are the Perceived Stress (PSS) and Generalized Anxiety Disorder (GAD-7) scales. Furthermore, the literature has shed light onto the importance of the carotid intima-media thickness (c-IMT) measurement as a tool in evaluating the risk of cardiovascular disease. After all, heart disease has been reported as being the number one killer of Americans in recent years. The specific aims of this study were to determine if there was an association between perceived stress / generalized anxiety and c-IMT (static association), and also if higher levels of perceived stress / generalized anxiety result in a significant increase in c-IMT (changes over time). METHODS: Data was collected on about 700 participants comprised of employees from Emory University in Atlanta, Georgia. At baseline, six, twelve, and twenty-four months, the largest number of participants had completed and calculated their scores on the PSS and GAD-7 scales. At these same time points, participants had their IMT measured and recorded for the left and right common carotid arteries by a trained sonographer of the Emory Predictive Health Institute. Due to incomplete measurements and scores, only 228 participants were included for statistical analyses. This was still considered a suitable sample size given that this study only involved four measurement time points. Various statistical models were fitted for the data. All variables in the models were treated as categorical except for time which was continuous. Four separate models were built that included the variables perceived stress, age group, gender and time. In a similar manner, four models were built that included the variables generalized anxiety, age group, gender and time. AIC values, -2 log-likelihoods, partial correlations, p-values, and other relevant information were reported for these models. All statistical analyses were performed using the Statistical Analysis System (SAS), version 9.2. RESULTS: The mean c-IMT measurements for the Emory participants were higher than established normal ranges. A strong correlation existed between the PSS and GAD-7 two-year averages when treated as continuous variables (.7316, p <.0001). Likewise, a meaningful relationship existed when both scales were categorical (.4154, p < .0001). The analyses revealed that the left and right mean IMT measurements for the common carotid arteries modeled a linear trend with an unstructured covariance the best. The partial correlations for perceived stress and generalized anxiety revealed weak, but significant positive associations with the mean c-IMT measurement. Although the slope coefficients were not significant for perceived stress, an increase from below average to above average perceived stress level still resulted in an increase in mean c-IMT measurement. Conversely, mild generalized anxiety was found to be statistically significant in the regression model of the left mean c-IMT. This was after controlling for age group and gender. The p-value for mild generalized anxiety was 0.0258, and the slope coefficient was 0.04856. IMT measurements were consistently higher for males on both sides compared to females. They were also higher on the left side compared to the right. CONCLUSIONS: Failure to control anxiety could lead to c-IMT soaring to dangerous levels resulting in a myocardial infarction and/or cerebrovascular accident. Individuals should engage in healthy lifestyle practices that lower stress and anxiety levels to decrease the chances of cardiovascular disease. Based on this study’s findings, a person can certainly use their c-IMT readings, as well as their perceived stress and generalized anxiety scores, as indicators that lifestyle modifications may be needed.

Title: What explains variability in blood pressure readings? Multilevel analysis of data from 8,731 older adults in 20 Ontario Communities Objectives: Despite universal healthcare and drug coverage for adults aged 65 and over in Ontario, hypertension, a treatable condition, remains uncontrolled among many older adults. Moreover, there are geographic disparities in blood pressure and hypertension within and across Canadian provinces and territories. Using baseline data collected on 8,731 older adults participating in the Cardiovascular Health Awareness Program (CHAP) in 20 randomly selected Ontario communities, we investigated associations between systolic blood pressure (SBP) and individual- and community-level characteristics, controlling for self-reported use of blood pressure medications. Method: Older adults were recruited via invitation by local family physicians, public advertising and word of mouth to attend community pharmacy sessions. During the sessions, trained older adult volunteers assisted participants to complete a cardiovascular disease risk factor questionnaire and blood pressure assessments using an automated blood pressure measuring device. The Postal Code Conversion File Plus was used to confirm residence within one of the 20 study communities. A multilevel linear regression analysis with participants nested within communities was used to determine which individual- and/or community-level characteristics were associated with measured systolic blood pressure level controlling for self-reported use of blood pressure medication. Results: 4,706 participants (53.9%) reported the use of blood pressure medication. Mean systolic blood pressure (SBP) levels varied among the 20 communities from 128.1 mmHg to 134.7 mmHg for participants not using blood pressure medication and from 131.9 mmHg to 139.0 mmHg for participants using blood pressure medication. The intraclass correlation coefficients were very small: less than 0.2% of the total variance was between communities. Among participants not using blood pressure medication, SBP was associated with the following individual- level characteristics: age, sex, body mass index , smoking, physical activity, stress, fruit/vegetable intake, and alcohol consumption and the following community-level characteristics: community size, community growth and the Rurality Index. Among participants using blood pressure medication, SBP was associated with the following individual-level characteristics: age, sex, body mass index, diabetes, fruit/vegetable intake, alcohol intake and one community-level characteristic: community size. The significance and magnitude of these associations were modified by the use of blood pressure medication. Conclusion: The majority of the variability in blood pressure occurs at the individual-level. There are specific individual- and community-level factors that explain variability in blood pressure readings among communities. These results can be used to inform health promotion strategies to decrease mean levels of blood pressure among older adults.

Prolonged time sitting has been linked to an increased risk of cardiovascular diseases (CVD), cardiovascular mortality (CVM), all-cause mortality, diabetes and some cancers. Workers in occupations where there is no alternative to sitting can best be defined as compulsory sedentary workers , which involve bus and lorry drivers amongst others. Limited research is available on the health behaviours and health profiles of individuals working within these occupations. This thesis adopts a mixed methods approach and fits within the MRC framework for the development of complex interventions to specifically investigate bus and lorry drivers sedentary behaviours and physical activity levels in association with their cardiovascular health. Chapter 3 describes a pilot study, which results showed bus drivers accumulate 12 hours sitting on workdays and presented higher than the recommended ranges for BMI, body fat, waist circumference and blood pressure. Chapter 4 explores the validity of using an ActiGraph accelerometer compared to the activPAL to assess bus drivers sedentary behaviours. Results highlight that compared to the activPAL, the ActiGraph underestimates sedentary time during workdays (151minutes/day) and working hours (172min/day). Chapter 5 phenotypes UK lorry drivers sedentary behaviours and non-sedentary behaviours during workdays and non-workdays and examines lorry drivers markers of cardiovascular health. Lorry drivers accumulate 13 hours sitting on workdays and 8 hours on non-workdays and presented an ill-cardiovascular profile. Chapter 6 examines the effects of an intervention designed to promote PA and reduce sedentary time on a range of cardiovascular risk factors in a sample of lorry drivers. Chapter 7 presents a process evaluation of the Structured Health Intervention for Truckers (SHIFT) programme described in Chapter 6. This thesis highlights that bus and lorry drivers accumulate the highest amount of sitting time reported up to date, together with high levels of physical inactivity and an ill-cardiovascular profile. However, positive changes in cardiovascular risk factors were observed when drivers increased their daily average of step counts. Overall, these results emphasise that targeting bus and lorry drivers health behaviours should be a public health priority.

The importance of physical exercise tends to be neglected in today’s modern lifestyle. This increased passive way of life conveys a notable increase in the prevalence of lifestyle disorders such as hypertension and vascular pathology which lead to cardiovascular strain. Taking this into account, the aim of this investigation was to explore the empirical association between the heart health status of an active and sedentary South African lifestyle, thus intending to provide insight into impact of the significant changes that are associated with the modernised society. With the aforementioned objective in mind, four separate studies were completed: Study 1 sought to investigate the cardiovascular status of 162 undergraduate university students in order to determine whether, despite their youth, students remained at risk of cardiovascular complications. Astonishingly, results indicate that a number of students between the ages of 18 and 25 in a university setting present with preeminent cardiovascular risk. This data highlights some serious concerns regarding the cardiovascular health among the youth. In sequel to study 1, study 2 permitted the comparison of a sedentary and active South African population, however some discrepancies originated due to the notable age difference between the groups. Nevertheless, results gained from this crosssectional comparison between the populations indicate significantly higher cardiac risk amongst the sedentary population. Study 3 was conducted on 202 infantry service recruits between the ages of 18 and 24 years. A pre- post intervention study design was incorporated in pursuit of determining the influence of an intense training programme on cardiovascular variables of a population over a 20 week time-frame. Results yielded from this study indicate a significant decrease in overall cardiovascular risk, as tested over three intervals (week 1, week 12, and week 20) during the 20 week training period. Study 4 was designed as a longitudinal study with self-controls for within group comparisons, as well as a comparative study between the two contrasting populations. Thus, affording the opportunity to determine the impact of physical activity on cardiovascular risk by comparing two divergent South African lifestyles over a 20-week time frame. The 202 infantry service recruits of study 3 served as the intervention group, while the control group comprised of 126 sedentary university students. Findings from this study conveyed strong association between the active population and decreased cardio-stress index and related heart health measurements in comparison to results of the sedentary population. This research validates the positive correlation between a physically active lifestyle and improved heart health, thereby implying reduced cardiovascular risk. In the combat against cardiovascular disease it is clear that focus should be shifted from pharmacological treatment to behavioural prevention. As a principle component of this preventative approach it is vital that individuals are equipped with screening technology that enables early detection and monitoring of probable cardiovascular complications. Several novel ideas were introduced in this research, including the endorsement of the cardio-stress index method as an efficient non-invasive technique to directly observe cardiovascular stress. / Dissertation (MSc)--University of Pretoria, 2014. / lk2014 / Physiology / MSc / Unrestricted

Title: What explains variability in blood pressure readings? Multilevel analysis of data from 8,731 older adults in 20 Ontario Communities Objectives: Despite universal healthcare and drug coverage for adults aged 65 and over in Ontario, hypertension, a treatable condition, remains uncontrolled among many older adults. Moreover, there are geographic disparities in blood pressure and hypertension within and across Canadian provinces and territories. Using baseline data collected on 8,731 older adults participating in the Cardiovascular Health Awareness Program (CHAP) in 20 randomly selected Ontario communities, we investigated associations between systolic blood pressure (SBP) and individual- and community-level characteristics, controlling for self-reported use of blood pressure medications. Method: Older adults were recruited via invitation by local family physicians, public advertising and word of mouth to attend community pharmacy sessions. During the sessions, trained older adult volunteers assisted participants to complete a cardiovascular disease risk factor questionnaire and blood pressure assessments using an automated blood pressure measuring device. The Postal Code Conversion File Plus was used to confirm residence within one of the 20 study communities. A multilevel linear regression analysis with participants nested within communities was used to determine which individual- and/or community-level characteristics were associated with measured systolic blood pressure level controlling for self-reported use of blood pressure medication. Results: 4,706 participants (53.9%) reported the use of blood pressure medication. Mean systolic blood pressure (SBP) levels varied among the 20 communities from 128.1 mmHg to 134.7 mmHg for participants not using blood pressure medication and from 131.9 mmHg to 139.0 mmHg for participants using blood pressure medication. The intraclass correlation coefficients were very small: less than 0.2% of the total variance was between communities. Among participants not using blood pressure medication, SBP was associated with the following individual- level characteristics: age, sex, body mass index , smoking, physical activity, stress, fruit/vegetable intake, and alcohol consumption and the following community-level characteristics: community size, community growth and the Rurality Index. Among participants using blood pressure medication, SBP was associated with the following individual-level characteristics: age, sex, body mass index, diabetes, fruit/vegetable intake, alcohol intake and one community-level characteristic: community size. The significance and magnitude of these associations were modified by the use of blood pressure medication. Conclusion: The majority of the variability in blood pressure occurs at the individual-level. There are specific individual- and community-level factors that explain variability in blood pressure readings among communities. These results can be used to inform health promotion strategies to decrease mean levels of blood pressure among older adults.

abstract: This dissertation was guided by the Ecological Model of Physical Activity and Ecological Model of Obesity and sought to determine the relationship between active transportation (AT), physical activity, and cardiometabolic health among adults and ethnic minority women. Chapter 2 presents an investigation into the relationship between walking for AT and cardiometabolic health among adults through systematic review. Chapter 3 presents an exploration of the cross-sectional relationships of AT and moderate-to-vigorous physical activity (MVPA) with cardiometabolic health among African American (AA) and Hispanic/Latina (HL) women from Texas. Chapter 4 presents an investigation into the cross-sectional relationship of AT on cardiometabolic health and physical activity among primarily HL women. In Chapter 2, walking for AT was found to be related to smaller waist circumference, lower blood pressure, and lower prevalence of abdominal obesity and hypertension, and that differences may exist based on sex. Walking for AT was not clearly defined, and criteria used to determine the presence of cardiometabolic outcomes were inconsistent. No significant relationships between AT and cardiometabolic health were found in Chapter 3 or 4; however, AT users had slightly better cardiometabolic health. AT users had significantly higher levels of self-reported total physical activity compared to those who did not use AT in Chapter 3. Furthermore, a significant relationship was found between MVPA and diastolic blood pressure. Associations differed by ethnicity, with MVPA being inversely related to body fat in both AA and HL women, but to body mass index only in AA women. AT users were found to be seven times more likely to meet 2018 national MVPA recommendations than non-AT users in Chapter 4. Across all studies, measures of AT were subjective and of low quality, potentially limiting the ability to detect significant findings. High quality randomized controlled studies should be conducted using clearly defined, objective measures of AT, and analyzed based on sex and race/ethnicity. Clinicians should recommend AT use to promote meeting MVPA recommendations where appropriate, potentially resulting in improved cardiometabolic health. Policymakers should advocate for changes to the built environment to encourage AT use and MVPA to improve public health. / Dissertation/Thesis / Doctoral Dissertation Nursing and Healthcare Innovation 2019

The pediatric population is highly impacted by brain tumours, as they are the most common type of solid tumour affecting children. Medical advances have improved the survival rate of children with brain tumours, but many survivors still experience late effects. In adulthood, 18% of pediatric brain tumour (PBT) survivors have reported cardiovascular issues such as strokes, blood clots, and angina, but little is known about the cardiovascular health of these survivors during childhood. The primary objective of this thesis was to measure the proportion of PBT survivors with values of body mass index (BMI), waist circumference (WC), and aerobic fitness meeting the cut-offs associated with unfavourable cardiovascular health (BMI≥+2 SDs, WC≥90th percentile, and % peak oxygen uptake (VO2peak) predicted<85%). The secondary objective was to observe the effects of 12 weeks of exercise training on the BMI, WC, blood pressure (BP), and aerobic fitness of PBT survivors and describe the feasibility of an exercise training program for this population. In this thesis, 32 PBT survivors who had all received cranial radiation were included (age=12.3±3.4 years, age at diagnosis=7.0±2.5 years, time since treatment completion=4.5±2.8 years, 21/32 male). While WC was measured for 13/32 participants, BMI and aerobic fitness were measured for all. Of the participants, 5/32 children completed a 12-week pilot exercise program consisting of two group and two in-home exercise sessions per week. A control group (n=2, age=14.8±3.6 years, 1/2 male) and an intervention group (n=5, age=15.0±2.3, 3/5 male) had BMI, WC, BP, and aerobic fitness measurements taken pre- and post-training. Of the participants, 15.6% (5/32) had a BMI≥+2 SDs, 30.7% had a WC≥90th percentile, and 86.7% had a %VO2peak predicted<85%. In total, 81% (26/32) of the participants had at least one identified biomarker reflecting unfavourable cardiovascular health. A training effect was only observed in BP (change of +9%). The exercise program was feasible with an adherence rate of 88% (21/24) to the group and in-home sessions. All (5/5) participants completed the program without injuries or adverse events during the training program. Findings from this thesis indicate that 81% brain tumour survivors have at least one biomarker indicating unfavourable cardiovascular health in childhood. This thesis also provides novel information to be considered before implementing exercise as a therapy for improving the cardiovascular health of survivors. Future additional research is required to determine the appropriate duration, frequency, and intensity of aerobic exercise to stimulate a training effect on these cardiovascular biomarkers. / Thesis / Master of Science (MSc)

Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) are sensitive markers of cardiovascular damage and repair, respectively. The aim of this thesis was to advance the state of knowledge regarding CECs and EPCs, and the factors affecting their concentrations, in children and adolescents. The first and second studies demonstrated that CECs and EPCs were similar when participants were split by sex, chronological age (8-10 vs. 14-16 years), and biological age (≤ -1 vs. ≥ +1 year from peak height velocity). Moreover, CECs, but not EPCs, were positively associated with aerobic fitness and negatively related to daily moderate-to-vigorous physical activity. Neither CECs nor EPCs were related to level of adiposity. Although there was a large degree of inter-individual variability in both cell types, most of our data were clustered towards one end of the reported range. These observations highlighted the need to examine these cells in children with chronic conditions associated with an increased risk of poor cardiovascular health. Therefore, CECs and EPCs were examined at rest and in response to acute exercise in juvenile idiopathic arthritis (JIA) and healthy controls. Resting levels of CECs and EPCs were similar in both groups, which may be attributable to the low disease activity in the participants with JIA. High intensity, intermittent exercise (HIIE) and moderate intensity, continuous exercise (MICE) had no effect on CECs in both groups. Conversely, MICE led to a robust increase in EPCs in healthy controls; no such change was observed in youth with JIA. This thesis represents the first comprehensive assessment of CECs and EPCs in the context of fitness, physical activity, and acute exercise in children and adolescents. Future research should examine the function and fate of these cells in youth, as well as the potential mechanisms underlying the blunted EPC response to exercise in JIA. / Thesis / Doctor of Philosophy (PhD) / Fitness and physical activity are critical for maintaining and improving cardiovascular health in children and adults. We don’t know exactly how they do this but the evidence in adults suggests it may be related to rare cells in the blood involved in repairing damaged blood vessels. The main objective of this thesis was to learn more about these cells, called circulating endothelial cells and endothelial progenitor cells, in children. We found that only circulating endothelial cells were related to fitness and physical activity. We also found that endothelial progenitor cells increased when healthy children performed 60 minutes of cycling. On the other hand, these cells did not change when children with juvenile idiopathic arthritis performed the same exercise. More research is needed to determine exactly why these cells responded to exercise in healthy but not sick children, and to help us identify the optimal exercise to improve these cells in youth.