Aging is associated with cognitive decline in various domains, including memory. The age-related increase in systemic inflammation has been identified as a potential mechanism contributing to these memory impairments. Specifically, elevated inflammation may impair neurotrophic factor production and function, which is important for maintaining brain health. Physical activity has been identified as a potential strategy for preventing or delaying memory decline, given its ability to reduce inflammation and stimulate neurotrophic factor expression. The present study investigated the relationship between cardiorespiratory fitness, a proxy for habitual physical activity, and memory in older adults. Inflammation and neurotrophic factors were examined as potential mechanisms mediating this relationship. Sixty-five community dwelling older adults (Mage = 70.6 ± 4.0) completed the Rockport 1-mile walk test to predict their cardiorespiratory fitness, as well as the Mnemonic Similarity Task to assess memory. Serum samples were collected to examine inflammatory markers, including interleukin-6 (IL-6), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP), as well as neurotrophic factors, including brain derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1). No relationship was found between cardiorespiratory fitness and memory (p > .05). However, older adults with greater cardiorespiratory fitness had lower levels of IL-6 (p < .01) and TNF-α (p < .01) and trended towards higher levels of BDNF (p = .078). Furthermore, IL-6 was negatively correlated with IGF-1 (p < .01), suggesting higher inflammation may impair IGF-1 production. Contrary to our hypotheses, sequential mediation analyses revealed no indirect effect of inflammatory markers and neurotrophic factors on the relationship between cardiorespiratory fitness and memory. Our results suggest that cardiorespiratory fitness may promote favourable changes in inflammatory markers and neurotrophic factors, which—given previous literature—could help to support brain health with advancing age. More research is needed to further examine the relationship between cardiorespiratory fitness and memory. / Thesis / Master of Science (MSc)

The medial temporal hippocampal system exhibits high plasticity and is influenced by behavioral and socioenvironmental factors. Animal models have demonstrated the neuroplasticity of this system through environmental enrichment, exercise, and chronic stress. Human studies have replicated these findings, highlighting the positive impact of exercise and cardiorespiratory fitness, as well as the detrimental effect of chronic stress on brain structure. However, limited research has explored the differences between young and older adults in extrahippocampal regions of the medial temporal lobes. Additionally, the impact of psychosocial stressors such as perceived discrimination and moderating factors like sense of control on this brain system remains understudied. Furthermore, there is a lack of investigation into the neurobiological consequences of perceived discrimination as a significant psychosocial stressor on neurocognitive health. The goals of this dissertation project were to investigate the role of cardiorespiratory fitness and perceived discrimination on medial temporal hippocampal system neurocognitive integrity in humans. I had two hypotheses. First, higher cardiorespiratory fitness would correlate with higher extrahippocampal cortical thickness in young and older adults. Second, a greater number of experiences of perceived discrimination would correlate with reduced amygdala and anterior hippocampus volume in older adults. Two experiments were conducted to assess the impact of behavioral and socioenvironmental factors on medial temporal hippocampal system structure. In the first experiment, cross-sectional data were collected from two randomized clinical controlled trials (n = 100; 56 young adults and 44 older adults). In the second experiment data were collected from two pilot studies (n = 36). Finally, we discuss how the built and social environment, artificially created or modified areas where individuals live, work, or engage in recreational activities, can facilitate or impede behaviors that benefit brain health such as physical activity to increase cardiorespiratory fitness or social engagement. Experiment 1 used structural MRI and assessed cardiorespiratory fitness in sedentary young and older adults. The primary objective was to examine the relationship between cardiorespiratory fitness and entorhinal, parahippocampal, and perirhinal cortical thickness. The results indicated a positive association between cardiorespiratory fitness and cortical thickness in these regions, specifically in the left hemisphere of young adults. However, this relationship was not observed in older adults. Experiment 2 focused on the association between participants' perceived social discrimination experiences and amygdala and anterior hippocampus volume. Additionally, the moderating role of locus of control, a measure of self-efficacy, was examined. The findings revealed that higher levels of perceived social discrimination were associated with reduced amygdala and anterior hippocampus volume. Moreover, higher levels of locus of control attenuated the relationship between perceived social discrimination and these brain regions. The third project integrated the aforementioned ideas within the context of the built and social environment. The discussion centered around how systemic barriers within the environment can either support or hinder engagement in health-promoting behaviors like cardiorespiratory fitness. The importance of considering the built and social environment in clinical interventions was highlighted, with a focus on improving translation of research findings to benefit research participants. Factors such as safety, access to green spaces, and social connectedness were explored, particularly in relation to universal design and its potential to enhance healthy aging and accessibility while addressing systemic racism and structural barriers. These chapters provide evidence to inform policymakers, clinicians, and neuroscientists about the broader implications of clinical research in communities. By considering the impact of clinical interventions on the built and social environment, this work aims to promote health and well-being beyond laboratory settings.

Over the past several decades abdominal obesity and physical inactivity have increased at an alarming pace. Since both are related to adverse health risk it is important to determine their independent influence. It is well established that cardiorespiratory fitness (CRF, the ability to perform physical activity) and physical activity (PA) are negatively associated with cardiometabolic risk factors (commonly obtained risk factors for disease, e.g: TG, HDL, etc.). In other words, the higher a person’s levels of PA and fitness, the lower that person’s likelihood of developing cardiometabolic risk factors. Abdominal obesity is positively associated with cardiometabolic risk factors which means the more abdominally obese a person is, the more prone that person is to develop cardiometabolic risk factors. However, it is unknown whether PA influences cardiometabolic risk factors independent of fitness level and/or abdominal obesity. My study objective was to examine whether PA is associated with cardiometabolic risk factors independent of cardiorespiratory fitness and/or abdominal obesity in inactive abdominally obese women. The study enrolled 141 inactive abdominally obese women. PA, cardiorespiratory fitness, and cardiometabolic risk profile were measured in all participants. A novel feature of this study was the use of the accelerometer to objectively measure PA and to divide exercise into different levels of intensity, such as: low PA, moderate to vigorous PA (MVPA), etc. My findings revealed that abdominal obesity was positively associated with cardiometabolic risk independent of PA or CRF. I also observed that CRF was inversely related to cardiometabolic risk independent of PA or abdominal obesity. MVPA explained cardiometabolic risk factors by itself, but with insulin resistance measurements (2-hour glucose, and homeostasis model of assessment) this relationship was abolished when abdominal obesity and CRF were also taken into consideration. The findings of this study provide further support for the recommendation that waist circumference and CRF be included as routine measures screening for cardiometabolic risk factors in inactive obese women. Our findings also support the suggestion that even modest amounts of daily MVPA that are below the recommended threshold of 30 minutes/day convey health benefit. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-07-23 13:46:57.088

Aging is associated with increased insulin resistance, a condition in which the tissue response to insulin-stimulated glucose uptake is reduced. Insulin resistance is a strong predictor of disease and mortality. Aging is also associated with a decline in physical activity, lower cardiorespiratory fitness (ability to deliver oxygen to active muscles during exercise), and increase in abdominal fat. Both low cardiorespiratory fitness (CRF) and excess abdominal fat are associated with reduced insulin sensitivity in older adults. Improvements in CRF and abdominal obesity through exercise training may be responsible for improvement in insulin sensitivity. Several investigations have reported that changes in CRF and abdominal obesity through exercise are associated with changes in insulin sensitivity. To our knowledge, no prior study has assessed whether change in CRF or abdominal fat alone explains the association between exercise and improvement in insulin sensitivity in older adults. Our findings suggest that improvement in CRF may not explain the exercise-induced change in insulin sensitivity. The improvement in insulin sensitivity from exercise is explained through a decrease abdominal fat that also occurs with exercise. Additionally, improvements in waist circumference, a surrogate measure for abdominal obesity, and body mass index together explained a large portion of exercise-induced change in insulin sensitivity compared to either variable alone. Our findings suggest that exercise combined with a healthy diet will improve insulin resistance, a risk factor for development of type 2 diabetes and cardiovascular disease in older adults. Our findings suggest that the reduction in abdominal obesity is the conduit by which exercise improves insulin sensitivity in older adults. Although CRF is not related to exercise-induced change in insulin sensitivity, change in CRF from exercise has been reported to decrease risk for other health conditions, such as hypertension and all-cause mortality. Our findings suggest that clinicians should measure both waist circumference and body mass index when evaluating the effectiveness of a lifestyle-based treatment strategy for improving insulin resistance and its associated health outcomes in older adults. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-09-27 14:53:00.796

Master of Science / Department of Clinical Sciences / Matt Miesner / Minimal research is available pertaining to the suspected acute cardiac injury of cattle experiencing the early signs of respiratory disease. One of the limitations of cardiac disease diagnosis in cattle is the lack of accurate measurement of cardiac disease. Blood biomoarkers such as cardiac troponin I could be used. Cardiac troponin I is a serum biomarker for cardiac injury in humans and many veterinary species. The goal of this thesis is to evaluate biophysical changes including cardiac injury that holstien calves experience during acute pneumonia. The first objective of this research was to evaluate a point of care cardiac troponin I assay for use in the bovine. Purified bovine cardiac troponin I was used to validate the accuracy of the assay over a wide range of concentrations in an in vitro experiment. This point of care assay was capable of accurately identifying bovine cardiac troponin I. An in vivo experiment was conducted to evaluate concentrations of cardiac troponin I in healthy Holstein calves. Concentrations evaluated with the point of care assay were similar to concentrations of a previously validated immunoassay. The second objective was to evaluate biophysical changes including serum biochemistry, complete blood count, cardiac troponin I, and high resolution digital thermography in Holstein calves during the first fourteen days after induction of pneumonia. Fibrinogen concentration increased with lung disease severity. The changes observed were considered clinically significant. Cardiac troponin I increased as pneumonia progressed during the study in this population.

Made available in DSpace on 2014-06-11T19:30:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-27Bitstream added on 2014-06-13T20:21:21Z : No. of bitstreams: 1 barros_seb_dr_rcla.pdf: 887445 bytes, checksum: 944f1e2052c0ea22941e6cca91732214 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O envelhecimento promove mudanças nos diversos sistemas, especialmente músculo-esquelético e cardiopulmonar. Exercícios físicos regulares melhoram o condicionamento cardiorrespiratório, modificam as dimensões corporais e neuromusculares, amenizando o impacto do envelhecimento na capacidade funcional. Com o objetivo de analisar os efeitos do exercício físico sobre indicadores pulmonares e antropométricos em idosas, dois estudos foram realizados. O Estudo 1 observou os efeitos da especificidade do exercício sobre indicadores antropométricos e pulmonares em idosas. Quarenta mulheres acima de 60 anos, compuseram quatro grupos (Sedentárias, Hidroginástica, Musculação e Dança). O Estudo 2 verificou os efeitos de um Programa de Exercícios Generalizados (PEG) em indicadores antropométricos e pulmonares em mulheres sedentárias entre 60 a 78 anos. Participaram do estudo trinta e duas mulheres, que compuseram dois grupos: Controle (n=14) e Intervenção (n=18). Para ambos os estudos, foram analisadas as variáveis antropométricas (índice de massa corpórea, circunferência muscular do braço e panturrilha, dobra cutânea tricipital e relação cintura/quadril); nível de atividade física (Questionário de Baecke) e função pulmonar [pressões respiratórias máximas, mobilidade torácica e espirometria (capacidade vital forçada - CVF, volume expiratório forçado no primeiro segundo - VEF1, relação VEF1/CVF, fluxo médio expiratório forçado - FEF25-75% e pico de fluxo expiratório)]. No Estudo 2, as participantes foram reavaliadas após 4 meses de intervenção. No Estudo 1, para o nível de atividade física, houve diferenças quanto à especificidade do exercício (p ≤ 0,001) entre Sedentárias e demais... / Aging promotes changes in many systems, especially for musculoskeletal and cardiopulmonary functions. Regular physical exercise improves cardiorespiratory fitness and modifies body and neuromuscular dimensions, all while softening the impact of aging on functional capacity. To analyze the effects of physical exercise on pulmonary and anthropometric measurements in older women, two studies were conducted. Study 1 observed the effects of specific exercises on anthropometric and lung measurements in elderly women. Forty women over 60 years old in four groups (Sedentary, Hidroginastics, Bodybuilding and Dance) were studied. Study 2 examined the effects of a generalized exercise program (GEP) on anthropometric and lung measurements in sedentary women between 60-78 years. Thirty-two women, formed two groups: Control (n = 14) and Intervention (n = 18). For both studies, we analyzed anthropometric variables (body mass index, arm and calf muscle circumference, triceps skinfold thickness, and waist/hip ratio), level of physical activity (Baecke questionaire), pulmonary function [maximal respiratory pressures, thoracic mobility and spirometry (forced vital capacity - FVC, forced expiratory volume in one second - FEV1, FEV1/FVC, forced expiratory flow medium - FEF25-75% and peak expiratory flow)]. Participants were reassessed after four months of intervention. Study 1 participants were assessed according to level of physical activity, there were differences in the specificity of exercise (p ≤ 0,001) between sedentary and other groups as well as between hidroginastics and the two groups (dance and bodybuilding). In axillary thoracic mobility, there were differences between bodybuilding and the sedentary and dance groups (p ≤ 0,05). Differences also occurred for xiphoid thoracic... (complete abstract click electronic access below)

Orientador: Aparecido Antonio Camacho / Banca: Marlos Gonçalves Sousa / Banca: James Newton Bizetto Meira de Andrade / Banca: Aulus Cavalieri Carciofi / Banca: Wagner Luís Ferreira / Resumo: A obesidade canina é uma das enfermidades nutricionais mais frequentemente observadas nos animais de companhia e pode provocar sérias influências sobre várias funções orgânicas, limitando a longevidade do animal. Neste estudo, avaliaram-se as possíveis alterações cardiorrespiratórias decorrentes da obesidade canina, assim como os efeitos da perda de peso corporal. Para tanto, utilizaram-se 11 cães obesos. Estes foram submetidos à restrição calórica de forma a perderem 20% do peso corporal e 11 cães com peso corporal ideal. Esses animais foram divididos em três grupos experimentais GI (cães obesos), GII (cães obesos após a perda de peso) e GIII (cães controle). Primeiramente, avaliaram-se a estrutura e função cardíaca mediante os exames ecodopplercardiográficos e mensurações da pressão arterial. Na segunda parte da pesquisa, os três grupos foram submetidos ao teste de estresse farmacológico com a infusão contínua de doses crescentes de dobutamina. Posteriormente, estudou-se a função respiratória por meio da hemogasometria e espirometria. Os resultados revelaram que os cães obesos apresentaram leve dilatação atrial esquerda, alteração das fases de despolarização atrial e ventricular e repolarização ventricular com a infusão de 32 μg/kg/min de dobutamina, maior resposta cronotrópica positiva frente a ação da dobutamina, menor pressão parcial arterial de oxigênio, além de volume corrente e frequência respiratória mais elevada em comparação aos cães com peso corporal ideal (GII e GIII). Desta forma, concluiu-se que a obesidade canina influencia principalmente os parâmetros respiratórios, não alterando a função sistólica e diastólica ventricular esquerda e a pressão arterial sistêmica, como também a correção da obesidade reverte as alterações encontradas nos cães obesos. / Abstract: Canine obesity is one of the most frequently seen nutritional problems in pets and it can play an important role in organic functions and thereby restricts the animal longevity. This research evaluated the cardiorespiratory alterations of obese dogs and the effects of weight loss. For such, eleven healthy obese dogs underwent a caloric restriction weight-loss program, whose target weight was defined as 20% below their admittance body weight, as well as eleven ideal weight dogs. These animals were assigned into three experimental groups: GI (obese dogs), GII (obese dogs after weight loss) and GIII (ideal weight dogs). Firstly, the cardiac structure and function were assessed by echodopplercardiographic exam and arterial blood pressure mensurement. In the second part, the three groups were submitted to dobutamin stress testing. In either situation, the respiratory function was assessed by arterial blood gas analyses and spirometry. The results of obese dogs showed mild left atrial dilation, the influence of atrial and ventricular depolarization and ventricular repolarization alteration with 32 μg/kg/min of dobutamin, higher positive chronotropic response to dobutamin, lower oxygen arterial tension and tidal volume and higher respiratory rate than ideal weight dogs (GII and GIII). It was possible to conclude that canine obesity is detrimental mainly to respiratory parameters and do not change left ventricular systolic and diastolic function and systemic blood pressure, and weight loss can resume these abnormalities. / Doutor

Abstract Objective: In Christchurch there is concern that winter air pollution, dominated by particulate matter (PM₁₀) from domestic heating, causes a local increase in cases of cardiorespiratory disease. Our aim was to investigate whether the particulate levels did influence emergency hospital admissions, and if so to what extent. Method: Air pollution and meteorological data was obtained from a Canterbury Regional Council monitoring station. Two local hospitals provided data on emergency admissions for both adults and children with cardiac and respiratory disorders. All data was obtained for the period from June 1988 to December 1998. Missing PM₁₀ data was interpolated from other known pollution values when necessary. The PM₁₀ data was compared to the admissions data using a time series analysis approach, with weather variables controlled for using a generalised additive model. Results: There was a significant association between PM₁₀ levels and cardiorespiratory admissions. For children and adults combined there was a 3.4% increase in respiratory admissions for every interquartile (14.8 µg/m³) increase in PM₁₀. In adults there was a 1.3 % increase in cardiac admissions for each interquartile increase in PM₁₀. There was no relationship between PM₁₀ levels and appendicitis, the condition that we selected to be our control. Conclusion: In Christchurch there is a significant relationship between particulate levels and the admissions for cardiac and respiratory illnesses. The size of the effect is comparable to other international studies, and the greatest impact is seen on the respiratory system.

Orientador: Lilian Teresa Bucken Gobbi / Banca: Maria José de Carvalho Costa / Banca: Gesualdo Pereira Soares / Banca: Claudio Alexandre Gobatto / Banca: José Riani Costa / Resumo: O envelhecimento promove mudanças nos diversos sistemas, especialmente músculo-esquelético e cardiopulmonar. Exercícios físicos regulares melhoram o condicionamento cardiorrespiratório, modificam as dimensões corporais e neuromusculares, amenizando o impacto do envelhecimento na capacidade funcional. Com o objetivo de analisar os efeitos do exercício físico sobre indicadores pulmonares e antropométricos em idosas, dois estudos foram realizados. O Estudo 1 observou os efeitos da especificidade do exercício sobre indicadores antropométricos e pulmonares em idosas. Quarenta mulheres acima de 60 anos, compuseram quatro grupos (Sedentárias, Hidroginástica, Musculação e Dança). O Estudo 2 verificou os efeitos de um Programa de Exercícios Generalizados (PEG) em indicadores antropométricos e pulmonares em mulheres sedentárias entre 60 a 78 anos. Participaram do estudo trinta e duas mulheres, que compuseram dois grupos: Controle (n=14) e Intervenção (n=18). Para ambos os estudos, foram analisadas as variáveis antropométricas (índice de massa corpórea, circunferência muscular do braço e panturrilha, dobra cutânea tricipital e relação cintura/quadril); nível de atividade física (Questionário de Baecke) e função pulmonar [pressões respiratórias máximas, mobilidade torácica e espirometria (capacidade vital forçada - CVF, volume expiratório forçado no primeiro segundo - VEF1, relação VEF1/CVF, fluxo médio expiratório forçado - FEF25-75% e pico de fluxo expiratório)]. No Estudo 2, as participantes foram reavaliadas após 4 meses de intervenção. No Estudo 1, para o nível de atividade física, houve diferenças quanto à especificidade do exercício (p ≤ 0,001) entre Sedentárias e demais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Aging promotes changes in many systems, especially for musculoskeletal and cardiopulmonary functions. Regular physical exercise improves cardiorespiratory fitness and modifies body and neuromuscular dimensions, all while softening the impact of aging on functional capacity. To analyze the effects of physical exercise on pulmonary and anthropometric measurements in older women, two studies were conducted. Study 1 observed the effects of specific exercises on anthropometric and lung measurements in elderly women. Forty women over 60 years old in four groups (Sedentary, Hidroginastics, Bodybuilding and Dance) were studied. Study 2 examined the effects of a generalized exercise program (GEP) on anthropometric and lung measurements in sedentary women between 60-78 years. Thirty-two women, formed two groups: Control (n = 14) and Intervention (n = 18). For both studies, we analyzed anthropometric variables (body mass index, arm and calf muscle circumference, triceps skinfold thickness, and waist/hip ratio), level of physical activity (Baecke questionaire), pulmonary function [maximal respiratory pressures, thoracic mobility and spirometry (forced vital capacity - FVC, forced expiratory volume in one second - FEV1, FEV1/FVC, forced expiratory flow medium - FEF25-75% and peak expiratory flow)]. Participants were reassessed after four months of intervention. Study 1 participants were assessed according to level of physical activity, there were differences in the specificity of exercise (p ≤ 0,001) between sedentary and other groups as well as between hidroginastics and the two groups (dance and bodybuilding). In axillary thoracic mobility, there were differences between bodybuilding and the sedentary and dance groups (p ≤ 0,05). Differences also occurred for xiphoid thoracic... (complete abstract click electronic access below) / Doutor

One of the earliest symptoms of Alzheimer’s disease (AD) and age-related cognitive decline is topographical disorientation or impairment to spatial navigation. Furthermore, aging and AD are associated with cortical gray-matter thinning, particularly in the medial temporal and posterior cingulate regions, which have been associated with spatial navigation. Aerobic exercise has been well-established as a beneficial intervention to curtail the neurodegenerative effects of aging. This study aims to explore the relationship between cardiorespiratory fitness (CRF), and two markers of AD and cognitive aging, virtual navigation ability and cortical thickness of the entorhinal, parahippocampal and retrosplenial regions. Cross-sectional data utilized in this study was collected from 23 healthy older adults (60-80 years). Measures included in our analyses consisted of estimated VO2max, T1-weighted structural MR images, and behavioral performance on a virtual navigation task, measured as numbers of objects located during recall. Cortical thickness of the regions of interest (ROIs) was determined by processing T1-weighted MR images in FreeSurfer. We hypothesized that greater CRF would correlate with improved virtual navigation performance and greater cortical thickness of ROIs. Our analyses did not reveal statistically significant relationships between CRF and navigation performance or CRF and cortical thickness. However, Pearson’s correlations found right retrosplenial cortical (RSC) thickness and navigation performance to be significantly related. Multiple regression models of right RSC thickness and navigation performance were performed controlling for age, sex, education and task version. These analyses revealed that greater right RSC thickness predicted navigation performance. Additionally, this model showed that older age predicts decline in navigation performance. Our findings did not survive multiple comparisons correction; nonetheless, the results provide promising insight to the relationship between cortical thickness and navigation performance in healthy aging. Further cross-sectional and longitudinal investigations with a larger sample size are required to assess the impact of CRF and exercise on cortical thickness and navigation abilities in healthy aging. Understanding these relationships would contribute to the expansive body of literature that has linked CRF and exercise to neuroprotective mechanisms in the aging brain.