Kinesiology & Health Science

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Effects of Manipulating Optic Flow Gain on Dynamic Postural Control During Continuous Support Surface Translations
(2024-07-18) Laurenza, Daniel Alon; Cleworth, Taylor
Human postural control involves interactions between visual, vestibular, and somatosensory systems to maintain upright stance. Quiet stance assesses posture when participants are standing still, and dynamic postural control has been assessed through use of moveable support surfaces. Limited work utilizes VR-induced optic flow with continuous platform translations to examine balance. SS oscillations perturbed participants in the A-P direction. Kinetic and kinematic information was quantified into center-of-pressure, center-of-mass, and joint and segment angles. We observed that as gain values increased, participants experienced a relative decrease in sway amplitude, and increases in both sway frequency and velocity, reflecting a tighter regulation of stance with greater visual information. These changes were generally more evident in the second minute of trials. By further examining dynamic postural control and its relationship with optic flow through VR, this thesis demonstrated the effectiveness of utilizing visual information to impact postural behaviours in young, healthy adults.
Open Access
Are We Oppressed or Liberated or Both? A Case Study of Persian Women Medical Doctors in Ontario
(2024-07-18) Fouladirad, Tanaz; Nakamura, Yuka
This study focuses on Persian women medical doctors and their lived experiences of immigrating to and settling in Canada, with particular focus on how they came to work as medical doctors in Ontario, and how these experiences shaped their gendered and racialized identities. Drawing on post-colonial feminist theory, this thesis entails a case study, where data were collected through (1) semi-structured interviews with Persian women medical doctors and (2) textual analysis of Canada’s Immigration and Citizenship website and documents pertaining to professional accreditation and credentialling. The findings illustrate the study participants were able to successfully immigrate to Canada via the points system because of their education, training as medical doctors, and English language skills, having been educated in English. However, upon arrival, these same resources constrained settlement. In response, the women in this study exercised their agency and resisted stereotypes of being docile, submissive, and complacent Muslim women.
Open Access
Branched-Chain Amino Acid Catabolism: Regulation and Effect on Insulin Resistance
(2024-07-18) Mann, Gagandeep Singh; Adegoke, Olasunkanmi A. J.
Insulin resistance is the reduced responsiveness of a target tissue to insulin. Insulin resistance is an underlying cause of Type 2 diabetes mellitus (T2DM) and cardiovascular diseases, two debilitating diseases. Therefore, targeting insulin resistance can help prevent the development of T2DM and cardiovascular diseases. Dietary protein, and in particular branched-chain amino acids (BCAAs; leucine, valine and isoleucine) stimulate muscle protein synthesis, and regulate body weight and glucose homeostasis. However, despite these benefits, circulating levels of BCAAs and BCAA metabolites, branched-chain a-ketoacids (BCKAs) are upregulated in insulin-resistant states like T2DM. This raises the question if upregulated levels of BCAAs and BCKAs cause insulin resistance or are a symptom of insulin resistance. Numerous studies have also shown how insulin resistant states can regulate the BCAA catabolic pathway and the enzymes involved, and how targeting this pathway can provide benefits in regards to insulin resistance and its sequalae. Thus, the purpose of this dissertation is to examine the link between BCAAs and their metabolism, and insulin resistance. Previous in vitro studies have showed that depletion of branched-chain ketoacid dehydrogenase (BCKD), the enzyme responsible for the catabolism of BCKAs, suppressed insulin-stimulated glucose uptake in L6 myotubes and the metabolite of leucine, ketoisocaproic acid (KIC) worsens it. Thus, I demonstrated that interventions that increased BCKD activity improved insulin sensitivity and attenuated the suppressive effect of KIC on insulin sensitivity in L6 myotubes. We have previously shown that KIC reduces insulin-stimulated glucose transport in muscle cells. However, contributions from other tissues aside from skeletal muscle in BCAA metabolism emphasize the importance of studying the effect of KIC gavage in vivo as well. Whereas KIC alters insulin signaling in the liver, it did not affect whole-body insulin tolerance. Finally, since BCAA catabolism is implicated in many chronic conditions like insulin resistance, and age is a major risk factor in insulin resistance, we assessed how aging affects BCAA catabolism in both sexes. There was an increase in plasma BCAAs of old male mice, but changes in BCAA levels in plasma/tissues were not largely consistent with any changes in metabolic enzyme abundance/activity and did not correlate with changes in insulin sensitivity with sex or aging. Taken together, this thesis shows that although KIC suppresses glucose transport in vitro and its effect is attenuated by increasing BCAA oxidation, it does not affect insulin sensitivity in vivo likely due to contributions of the liver to catabolize KIC. Also, increases in plasma BCAAs seen in older male mice does not correlate with increased insulin resistance, suggesting that greater BCAAs in plasma may only be present in disease states. Together these studies suggest that altered BCAA levels do not cause insulin resistance but are a result of insulin resistance.
Open Access
USPORT Student Athletes’ Dietary Habits and the Impact of Various Barriers on Nutritional Intake and Health/Performance
(2024-07-18) Morassutti, Emerson Donneral; Macpherson, Alison
Introduction: Collegiate athletes face unique lifestyle circumstances compared to other athletic populations that can affect their daily nutrition habits. Purpose: To understand student-athletes (SAs) dietary habits and identify barriers faced by SAs that impact food intake. Methods: Cross-sectional study using an 89-question survey. Results: Thirty percent of SAs included in this study reported not consistently eating 3 meals per day and 46% reported being hungry before going to bed. Almost 75% of SAs reported that they were not able to access high quality food on campus and 80% reported that their daily schedule limited their ability to cook and prepare meals. More than half of SAs reported worrying about running out of food due to a lack of money. Conclusion: Lack of time, financial issues, and limited access to food on campus were prevalent barriers that affected nutritional intake
Open Access
The Effect of Age and Sex on Chemotherapy-Induced Cachexia and Branched-Chain Amino Acid Metabolism
(2024-07-18) Mora, Stephen; Adegoke, Olasunkanmi A. J.
Cachexia remains one of the most complex and challenging aspects in cancer care. The impact of cachexia on body wasting, particularly on the depletion of muscle mass, significantly impairs patient’s energy, strength and quality of life. Tumour-related factors and poor nutritional status are associated with cachexia development. Additionally, while effective in combatting cancer, chemotherapy causes appetite loss, fatigue, altered metabolism and decreased physical activity, all contributing to muscle tissue breakdown and cachexia. Decades of research into investigating interventions to mitigate the effects of cachexia have been unsuccessful. Even the use of nutritional supplements like the branched-chain amino acids (BCAA) in reversing cachexia remains limited and inconsistent. However, researchers typically prioritize tumour BCAA metabolism and overlook these amino acids in the skeletal muscle. In addition, studies investigating chemotherapy-induced cachexia frequently utilize young male animals and the effects of chemotherapy on the abundance and activity of enzymes involved in BCAA metabolism have not extensively been compared across the sexes, nor studied in aged animal tissues. Understanding the alterations in skeletal muscle BCAA metabolism and availability following chemotherapy, especially across different sex and age groups, may help provide a better understanding of why certain interventions are ineffective in treating cachexia and may present findings that more accurately represent clinical diversity. Therefore, the objective of this dissertation is to examine the effect of age and sex on the mechanisms and severity of chemotherapy-induced cachexia, with a focus on BCAA availability, metabolism and transporter expression in young and aged animals. Briefly, I showed that preventing the degradation of LAT1, a transporter protein crucial for BCAA uptake into skeletal muscle, counteracted the effects of chemotherapy-induced damage on myotubes. Further, in-vivo, I showed sex-dependent differences in the susceptibility of young and aged animals to chemotherapy-induced cachexia. I also show that altered BCAA availability and metabolism following chemotherapy may contribute to muscle wasting in a sex and age-dependent manner. Findings from this dissertation suggest that interventions regulating muscle amino acid transporters may represent a promising strategy to treat cachexia. These findings underscore the need for age- and sex-specific responses when developing interventions that can manage cachexia.
Open Access
Regulation of Substrate Metabolism and Renin-Angiotensin System with Dietary and Pharmacological Interventions: Implications for Obesity and Related Disorders
(2024-07-18) Da Eira, Daniel Pereira; Ceddia, Rolando
This dissertation investigates the effects of the ketogenic diet (KD) on adipose tissue (AT) metabolism and renin-angiotensin system (RAS) function and potential implications for other tissues, including lung, heart and skeletal muscle. In the first study, it was demonstrated that despite increasing fat mass, a KD enhanced energy-dissipating mechanisms in white AT (WAT) and brown AT (BAT) by upregulating the machinery for triacylglycerol recycling in white adipocytes and uncoupled fatty acid (FA) oxidation and UCP1 protein levels in the BAT. These effects could potentially be attributed to the shift to the counterregulatory RAS arm in WAT observed in study 2, which has been shown to produce beneficial metabolic effects. In study 3, the effect of the KD on RAS components was investigated in the context of the lung and heart, where an obesity-induced elevation in pulmonary inflammation could underlie an increase in angiotensin converting enzyme 2 (ACE2), the receptor for SARS-CoV-2 cellular infection. We observed that the obesogenic, high-fat sucrose-enriched (HFS) diet elevated the pulmonary content of this receptor, whereas the KD did not alter ACE2 levels. Moreover, the KD significantly suppressed inflammation, relative to the HFS group, in the lung. Because AT releases energy substrate for utilization in peripheral tissues, the KD also affects substrate preference and metabolism in skeletal muscle. To our knowledge, little has been done with respect the metabolic effects of a KD on muscles with distinct fiber-type compositions. Therefore, we assessed the effects of the KD on glucose, fat, and ketone metabolism in skeletal muscles. We observed that the KD increased fat oxidation and ketolytic capacity, when compared to the HFS group, in a fiber-type specific manner. However, irrespective of oxidative capacity, the KD preserved insulin-stimulated glucose metabolism, whereas the HFS diet suppressed this parameter. In our final study, we used a pharmacological intervention (the adiponectin mimetic ALY688) to alter AT glucose and fat metabolism. Despite not altering glucose uptake in Epid or Sc Ing adipocytes, ALY688 significantly enhanced glucose oxidation. Together, these projects explore dietary and pharmacological interventions that alter the metabolic and endocrine roles of AT and investigate non-adipose tissues under KD conditions.
Open Access
Regulating Inflammation Through Exercise-Mediated Trained Immunity or Genetic Manipulation of the Interferon Locus
(2024-07-18) Murugathasan, Mayoorey; Abdul-Sater, Ali
Abstract Inflammation is a protective early immune response to infection or injury. A balanced inflammatory response, which is self-limiting and self-resolving, is essential to restore homeostasis. However, dysregulated inflammation is underlying many chronic diseases and infections. Strategies for balancing inflammation can be achieved in two ways 1) by inducing adaptations in immune cells through environmental/lifestyle factors such as exercise and 2) by genetically manipulating or pharmaceutically targeting key immune modulatory factors, such as interferons. In my thesis, I employed both approaches. First, we explored whether exercise training could induce adaptations in bone marrow-derived macrophages, resulting in trained immunity, known to occur in immune cells due to persistent metabolic and epigenetic changes. Data from this study suggest that chronic moderate exercise can influence the inflammatory responses of macrophages by reprogramming their metabolic and epigenetic landscape. Second, we evaluated the role of specific type I interferons (IFN-α and IFN-β), cytokines known for their antiviral and immunomodulatory functions, in virus infection and PAMPs (pathogen-associated molecular patterns) mediated inflammatory responses. To study this, we generated unique knockout (KO) mice of type I interferons (IFN-Is) locus and evaluated viral clearance and other parameters such as cytokine, interferon stimulated genes (ISG) signatures, and bone marrow hematopoiesis. Data from this study showed the importance of IFN-αs in early viral clearance and other parameters that measured antiviral and inflammatory responses, which encourages the need to study the individual IFN-Is in isolation using reliable mouse models to uncover their specific roles and targets. Overall, data from both approaches contributed significantly to improving our understanding of the mechanisms behind exercise and IFN-I mediated regulation of inflammatory responses.
Open Access
Exploration of the Mitochondria as a Potential Therapeutic Target in Duchenne Muscular Dystrophy
(2024-07-18) Bellissimo, Catherine Anne; Perry, Christopher G. R.
Duchenne muscular dystrophy (DMD) is a fatal muscle wasting condition resulting from the loss of the structural protein dystrophin. The disease is characterized by severe muscle wasting and weakness that results in early death due to cardiac and/or respiratory failure. Currently, there is no cure for DMD and current standard of care (glucocorticoid steroids) only addresses secondary pathologies, and is accompanied with a myriad of negative side effects. Previous work has established the mitochondria as a contributor to dystrophic pathology and a valid therapeutic target. The primary focus of this thesis was to examine novel therapies that modulate metabolism in DMD, to determine if secondary pathologies, including fibrosis, atrophy, weakness and mitochondrial stress are attenuated. Additionally, we aimed consider the effects of adenylates and creatine metabolism on mitochondrial permeability transition (mtPT) in a permeabilized muscle fibre system. Our study findings reveal that ATP significantly attenuates mtPT and that both creatine and ADP should be considered in buffer composition for assessment of mtPT. Next, using the mitochondrial-enhancing compound, Olesoxime, we examined the effect of attenuating mitochondrial stress on dystrophic pathology. Unexpectedly, improvements to mitochondrial respiration and reactive oxygen species attenuation, were creatine-dependent, indicating that creatine sensitivity was preserved by Olesoxime treatment. These improvements to bioenergetics also happened in association with markers of muscle breakdown (serum creatine kinase), and improvement in muscle function (cage hand time and recovery of diaphragm force after fatigue). Finally, short-term treatment with the novel adiponectin receptor agonist, ALY688-SR, mitigated aspects of mitochondrial stress in quadriceps, diaphragm and hippocampus, while improving markers of fibrosis and muscle atrophy in the diaphragm, and recognition memory. Overall, this thesis indicates that attenuating mitochondrial stress in dystrophic muscle and brain improves markers of muscle function and quality, while preserving cognitive function and warrants longer term treatment protocols.
Open Access
Investigating the function of TRAF1 in NF-κB activation
(2024-03-16) Tang, Yitian; Abdul-Sater, Ali
Tumour necrosis factor receptor-associated factor (TRAF) proteins play an important role in mediating the activation of NF-κB. Dysregulation of NF-κB may be one of the potential causes of chronic inflammatory diseases. One member of the TRAF family, TRAF1, has been shown to increase the risk of rheumatoid arthritis (RA). However, TRAF1 plays opposing roles in the activation of NF-κB downstream of the tumour necrosis factor receptors (TNFR) and toll-like receptors (TLR) signalling pathways. In the TNFR pathway, TRAF1 recruits c-IAP2 to promote NF-κB activation and cell proliferation. In contrast, in TLR pathways, TRAF1 negatively regulates NF-κB by sequestering the linear ubiquitin assembly complex (LUBAC). Because of the complex role of TRAF1 in NF-κB activation, it is important to isolate and study the role of TRAF1 in each of these pathways. To better understand TRAF1 and its role in NF-κB activation, our laboratory has identified the same interaction site between TRAF1 and c-IAP2 and created a mutant TRAF1V203A that significantly reduces the interaction with c-IAP2. This study creates a working functional assay to test the effect of these mutants on NF-κB activation. We have generated TRAF1V203A knock-in monocyte THP-1 cells and demonstrated how this mutant alters signalling downstream of TLR and TNFR in monocytes. This study also shows that the production of pro-inflammatory cytokines is reduced in TRAF1V203A mutant monocytes. This study helps us to isolate effects on NF-κB activation and provides an excellent model to study the role of TRAF1 in vivo.
Open Access
The association of physical activity with prediabetes/type 2 diabetes and cardiac autonomic function
(2024-03-16) Pooni, Rubin Kaur; Kuk, Jennifer
Three separate studies were conducted to assess the association of physical activity with prediabetes/type 2 diabetes (pre/T2D) and cardiac autonomic function. The purpose of study 1 was to examine whether using both objectively (accelerometer) and subjectively (questionnaire) measured moderate- to vigorous-intensity physical activity (MVPA) and sedentary time (SED) improves the prediction of pre/T2D using data from the Framingham Heart Study (n=4200). Logistic regression was used to examine the odds ratio of pre/T2D in groups cross-classified by subjective and objective MVPA and SED. The findings demonstrated that low objectively measured MVPA appears more closely associated with pre/T2D risk compared to subjective measures, and there does not appear to be an additive effect of SED on pre/T2D risk after accounting for MVPA. The purpose of study 2 was to examine the effects of 3-6 months of aerobic, resistance, and combined aerobic and resistance exercise training on heart rate recovery (HRR) from three previously reported randomized trials (n=147). A repeated measures ANCOVA was used to examine differences in 1-, 2-, 3-, 4-, and 5-min HRR from pre- to post-intervention and compared to control adjusting for sex, Tanner stage, ethnicity, and training duration. The findings suggest that aerobic exercise training may be a more effective strategy for improving HRR in adolescents with overweight or obesity. The purpose of study 3 was to examine the association of MVPA or SED and pre/T2D with heart rate variability (HRV) in Hispanic adults using data from the Hispanic Community Health Study / Study of Latinos (n=11 209). Multiple linear regression models were used to examine differences in RMSSD and SDNN in groups cross-classified by MVPA or SED with pre/T2D, adjusting for age, body mass index, sex, education, nutrition, smoking status, alcohol use, cardiovascular disease, and MVPA or SED where appropriate. Having pre/T2D, regardless of MVPA or SED, was associated with lower RMSSD and SDNN. There was an association of high HRV with high MVPA in individuals without pre/T2D, but it did not translate to individuals with pre/T2D. The association of MVPA and SED with HRV in individuals with pre/T2D requires further investigation.
Open Access
Effects of Pseudo-Positive Ageism: A Systematized Critical Review
(2024-03-16) Le, Matthew Hoang; Meisner, Brad
There has been scattered research that explores so-called ‘positive’ generalizations of ageism. These ‘positive’ forms of ageism are more subtle than the negative and is often overlooked in literature and society. The aim of this systematized critical review is to synthesize the current knowledge of these ‘positive’ forms of ageism. A comprehensive literature search was performed on 8 databases to identify primary research articles on the overarching concept of positive ageism. The systematic search yielded 2,216 studies to which 5 met the inclusion criteria and were selected for full text review/data extraction. Definitions of ‘positive’ ageism featured the term benevolent ageism. ‘Positive’ ageism was found to influence the affective state of younger people and the perceptions of older people. Furthermore, intersectional analysis found one study examining the interactions between age and gender. Results may aid to inform future research and policy on ‘positive’ ageism and its implications.
Open Access
Eminence in Endurance Cycling Sports
(2024-03-16) Korf, Jesse; Baker, Joseph
The objectives of this dissertation were to define and explore eminence in endurance cycling. To accomplish these objectives, both qualitative and quantitative approaches were used. Chapter 1 involved a narrative review of the literature and provides a historical account of the development of the body of knowledge around eminence in sport. In Chapter 2, a definition of eminence in a specific context of endurance cycling sports was explored. This was done by way of a Delphi method including two panels, the first involving athletes and the second involving technical experts such as coaches and performance directors. The next two chapters utilized quantitative designs where the research questions explored the developmental histories of athletes who met the criteria of eminence. For all quantitative analyses, the Union Cycliste International (UCI) database, which includes all UCI sanctioned race results from across the globe (~ 4.7 million race results), was interrogated. Several notable findings were revealed. In Chapter 2, criteria for the achievement of eminent status in endurance cycling sports were established, which included the need to win at least three high level races including the World Championships, Olympic Games and some sport specific races and general classifications such as the Tour de France and the Tour of Flanders in Road cycling and the World Cup general classification in Mountain Bike. Chapter 3 revealed that becoming an eminent cyclist was more strongly related to a diversified approach to racing across multiple cycling sports rather than fully specializing in a single cycling sport. Findings also revealed that those that achieved eminent status reached their first podium in elite races at a much younger age than those who did not. In Chapter 4, it was revealed that whilst junior to elite predictability varied between sports, junior performance in these cycling sports has a higher predictive value than suggested in other pieces of research on talent identification and development. In summary, this research program provides a framework for researchers to explore eminence in sport specific settings and provides guidance for administrators and coaches to increase the likelihood of athletes becoming eminent through specific selection and development approaches.
Open Access
The Effect of Circular Vection on the Subjective Postural Horizontal in the Pitch Plane
(2024-03-16) Hamam, Noor Jihad; Cleworth, Taylor
Postural orientation assessments, including the subjective postural horizontal (SPH) test, has been demonstrated as a great tool for assessing otoliths contributions to postural orientation and balance (Beule et al., 2006). Previous work has shown that dynamic visual stimuli, in the form of circular vection (CV) in the roll plane, significantly affects the body position and horizontal orientation perception of the support surface (Cleworth et al., 2023). However, CV in the pitch plane has been shown to introduce a different form of the visual stimulus and elicit distinct postural strategies compared to the roll plane. Therefore, by altering the support surface and visual information, this study aims to examine the effect of applying pitch CV in VR, on the body response and perception of horizontal orientation of the support surface. Overall, pitch CV significantly affected SPH of the platform and body position. This thesis contributes to our understanding of the complex integration of the visual and vestibular systems during postural orientation tests and offers a potential avenue for testing postural orientation and balance deficits in clinical populations.
Open Access
Evaluation of Percent Body Fat Estimates Using Different Body Composition Methods in Recreationally Active Adults Across Both Sexes
(2024-03-16) Davis, Devon F.; Josse, Andrea
This thesis compared percent body fat (%BF) values derived from different body composition (BC) modalities: air displacement plethysmography (Bod Pod), skinfold (SKF) prediction equations (Durnin and Womersley (DW), Jackson and Pollock (JP7), (JP3) and Yuhasz) with dual-energy x-ray absorptiometry (DXA) as the reference and compared whether they differed by sex. Utilizing data from 38 active individuals (20 females, aged 26.3±4.0 years; 18 males, aged 30.5±7.4 years), females demonstrated significant differences between all modalities with DXA (P<0.05), except for DW equations. Males demonstrated no significant differences with DXA (P<0.05), except for the Yuhasz equation. Bland-Altman (B-A) analyses found significant systematic biases (P<0.05) in females and males with magnitudes of difference ranging from -2.0% to -10% and -1.4% to -4.0%, respectively vs DXA. Significant proportional biases between different modalities and DXA were also evident in both sexes. These results highlight the importance of using the most appropriate BC approach to estimate %BF.
Open Access
The Role of FoxO1 and Sex Differences in Response to a DNA-damaging Agent
(2024-03-16) Martone, Christian Adelio; Haas, Tara
Endothelial cell (EC) health can be disturbed in various diseases like aging, obesity, atherosclerosis and type 2 diabetes. Previously, our lab showed that female ECs retain a healthier phenotype than male ECs under obesogenic conditions and that they have higher levels of Forkhead Box O1 (FoxO1) than male ECs. The goal was to investigate whether FoxO1 inhibition enhances EC vulnerability and whether any sex differences occur in response to an oxidant insult. To achieve this, ECs were treated with a FoxO1 inhibitor and treated with cisplatin. FoxO1 inhibition promoted cell cycle arrest and antioxidant induction in both sexes while DNA damage improved only in male ECs. Unperturbed female ECs displayed higher levels of γH2AX compared to male ECs. These data provide evidence that FoxO1 inhibition is potentially protective for the male EC while also revealing a potential sex disparity in the DNA damage response pathway.
Open Access
A Critical Examination of the Lived Experiences of Somali Refugees and Immigrants Diagnosed with Type 2 Diabetes and their Family
(2024-03-16) Abdulwasi, Munira; Nakamura, Yuka
This narrative study explores how the process of resettlement impacted the management/care of type 2 diabetes (T2D) among Somali immigrants and refugees living with T2D and/or family members of Somali immigrants and refugees living with this condition residing in Toronto. It also examines how the participants described their and/or family member/s illness. Family members were included in this study since research indicates that they can play a significant role in the care of individuals living with T2D (Black, Maitland, Hilbers, & Orinuela, 2016; Mayberry & Osborn, 2012; Protudjer, Dumontet, & McGavock, 2014). In total, 37 face-to-face interviews were conducted with 19 family members and 18 individuals living with T2D from Fall 2017 to December 2018. Data analysis involved analysis of narratives (Creswell, Hanson, Plano Clark, & Morales, 2007; Polkinghorne, 1995), which resulted in three themes across all participant narratives. These themes were then organized and presented through restorying three participant experiences. This study also included found poetry, displaying participants’ words from their interviews as a poem (Butler-Kisber, 2020). The first theme, ‘precarious settlement,’ describes the participants’ experiences dealing with stressors, such as unsafe neighbourhoods, un/underemployment, and poverty. The second theme, ‘gendering of T2D,’ illustrates the gendered ways in which the participants described T2D (as mainly a woman’s disease) and the gendered forms of care that were enacted by family members. Lastly, the third theme, ‘diabetes as bitter-sweet,’ explores how T2D was narrated and perceived by participants in this study, which included positive and negative accounts. This study recommends that further attention be placed to address the structural inequalities and barriers experienced by the participants. Mental health supports that are inclusive of the participants’ religious/cultural worldviews are also needed to support family members and individuals living with T2D in this population in dealing with diagnosis, care, and resettlement stressors that they may be experiencing.
Open Access
Exercise Modifies Inflammatory Responses by Changing the Epigenetic Landscape
(2024-03-16) Amandeep, Amandeep; Abdul Sater, Ali
Physical inactivity and low-grade systemic inflammation are associated with chronic metabolic diseases such as atherosclerosis, insulin resistance, obesity etc. It is of great value to study the exercise mediated benefits to alleviate inflammation. Preliminary work in our lab demonstrated that exercise with a particular intensity and duration led to reduced inflammatory responses in bone marrow derived macrophages (BMDMs) by inducing persistent metabolic changes in these cells. In this thesis, we explored how exercise is causing these long-lasting changes in inflammatory responses and hypothesized that it does so by inducing changes in chromatin accessibility leading to changes in gene expression. We employed an unbiased ATAC-seq (Assay for Transposase Accessible Chromatin- sequencing) analysis in BMDMs prepared from sedentary and exercised C57BL/6N mice and obtained a list of differentially accessible chromatin regions. We also demonstrated using real-time PCR that exercise-mediated changes in chromatin accessibility cause a reduction in gene expression of inflammatory genes. Our findings suggested that exercise is protective against inflammatory responses by causing persistent changes at chromatin level.
Open Access
A Fresh Perspective on Fat-Loss and Body Measurement Techniques: The Effects of Time Restricted Feeding and Exercise on Fat- Oxidation Rates and Commonly Used Fatness Measurements
(2024-03-16) Yavelberg, Loren; Jamnik, Veronica
Currently employed techniques for weight management consist of; extreme caloric deprivation alone or in combination with exercise, exercise alone or medically invasive procedures, all of which have proven not to provide sustainable resolutions (Brownell et. al., 1987; Kramer et. al., 1989). Due to the significance of a growing global obesity epidemic, the need for customized PA and exercise prescriptions which potentially increase fat-oxidation rate (FOR) are critical. To formulate a successful solution, examining both the acute and chronic effects of varying exercise intensities and modalities on FOR alone and in conjunction with healthier eating habits (time-restricted feeding (TRF) will be informative. A growing body of evidence suggests that TRF could be a valuable tool for improving health in the general population due to reports of improving blood lipids (Klempel et al., 2012 & 2013; Varady et al., 2011) and glycaemic control (Barnosky et.al., 2014), reducing circulating insulin (Trepanowski & Bloomer, 2010), decreasing blood pressure (Trepanowski & Bloomer, 2010; Tinsley & La Brounty, 2015; Varady & Bhutani, 2009), decreasing inflammatory markers (Farajeh et al., 2012) and reducing fat-mass (FM) even during relatively short durations (8–12 weeks) (Varady & Bhutani, 2009). Currently, little is known about the synergistic effects of TRF supplemented with varying forms of PA on FOR. In order to successfully improve FOR in individuals living with obesity and overweightness, exercise intensity, modality, and duration must be considered for successful weight loss. This series of investigations examined 1) Validated FOR at rest and during exercise, 2) The acute effects of TRF (12 & 16 hrs) and varying exercise intensities on FOR, 3) The short-term effects of intermittent fasting and continuous steady-state low-moderate intensity exercise on commonly used fatness measurements and FOR in middle-aged women, and 4) The importance of considering Body Mass Index in conjunction with VO2max when evaluating the health and wellness of frontline fire suppression personnel.
Open Access
The epidemiology of burn injuries in a Canadian population during the COVID-19 pandemic
(2024-03-16) Michelberger, Alexander John; Rotondi, Michael
Purpose: To investigate the changes in the epidemiology of burn injuries in a Canadian population during the COVID-19 pandemic. Methods: Data from the Canadian Institute for Health Information were used to evaluate differences in burn ED visits from before to during the COVID-19 pandemic. Logistic regression models estimated the odds of a severe burn occurrence. Results: During the pandemic, there were significant decreases in ED visits for burns. Distributions of factors associated with burns had little to no change. Period, age, gender, income, month, and daytime were significantly associated with severe burns during the pandemic. Conclusions: The study found large reductions in the number of ED visits during the pandemic, but no evidence of changes in the epidemiology of burns or patterns in the patient populations.
Open Access
Healthcare Worker Factors Influencing Reports of Pain Judgments about Older Patients with Cancer and Delirium
(2024-03-16) Carbone, Vanessa Luisa; Gagliese, Lucia
Healthcare workers (HCWs) rely on behavioural cues to judge pain in older adults with cancer and delirium. This study identified HCW factors associated with pain judgments about older patients with advanced cancer who are cognitively intact or have delirium, including the hypoactive, hyperactive, and mixed subtypes. Fifty-three HCWs with experience in pain-related specialties were interviewed on their experiences regarding pain judgments about this patient population. The Cancer Pain and Delirium Scale (CPDS) was used to score each interview transcript for reported pain cues for each patient group. Backward regression models found that age, discipline, specialty, years of experience in palliative oncology or geriatrics, percentage of older patients cared for per month, and pain catastrophizing each contributed to at least one of the models for CPDS INT, DEL, HYPO, and HYPER. These results support the biopsychosocial model of pain and aging and highlight the influence HCW factors have on pain assessments.