Browsing by Author "Doyle-Baker, Patricia K."
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Item Open Access A Mixed Methods Study on the Barriers and Facilitators of Physical Activity Associated with Residential Relocation(2018-11-01) Salvo, Grazia; Lashewicz, Bonnie M.; Doyle-Baker, Patricia K.; McCormack, Gavin R.Despite evidence suggesting that neighbourhood characteristics are associated with physical activity, very few mixed methods studies investigate how relocating neighbourhood, and subsequent changes in the built environment, influences physical activity. This sequential mixed methods study estimates associations between changes in overall physical activity and transportation walking and cycling and changes in objectively assessed neighbourhood walkability (quantitative phase) and describes perceived barriers and facilitators to physical activity following residential relocation (qualitative phase). During the quantitative phase, self-reported changes in transportation walking, transportation cycling, and overall physical activity following residential relocation were measured using a 5-point scale: (1) a lot less now, (2) a little less now, (3) about the same, (4) a little more now, and (5) a lot more now. Walkability improvers reported a slight increase in transportation walking (mean = 3.29, standard deviation (SD) = 0.87), while walkability decliners reported little or no perceived change in their transportation walking after relocation (mean = 2.96, SD = 1.12). This difference approached statistical significance (). Furthermore, walkability decliners reported a slight decrease in transportation cycling (mean = 2.69, SD = 0.96), while walkability improvers reported little or no perceived change in their transportation cycling after relocation (mean = 3.02, SD = 0.84). This difference was statistically significant (). Change in walkability resulting from relocation was not significantly associated with perceived change in overall physical activity. Our qualitative findings suggest that moving to a neighbourhood with safe paths connecting to nearby destinations can facilitate transportation walking and cycling. Some participants describe adjusting their leisure physical activity to compensate for changes in transportation walking and cycling. Strong contributors to neighbourhood leisure physical activity included the presence of aesthetic features and availability of recreational opportunities that allow for the creation of social connections with community and family.Item Open Access An Assessment of the Impact of Familial Resemblance and Other Factors on Bone Health Parameters in Daughter-Mother Pairs(2024-06-28) Boisvert, Nicole Marie Jeanne; Doyle-Baker, Patricia K.; Burt, Lauren A.; Tough, Suzanne C.Older females face a higher prevalence of osteoporosis and incidence of fragility fracture than older males. Evidence suggests that the groundwork that contributes to these conditions is laid in adolescence or young adulthood. In addition to the effects of lifestyle on bone health, there is also a high degree of heritability. Previous research has investigated and accounted for this by using mother-daughter study designs. This thesis aimed to determine the impact of heritability versus various factors (i.e., lifestyle, health, and reproductive history) on bone density, area and microarchitecture. Mother-daughter studies were compiled in a scoping review to determine trends in methodologies and findings. The results from the review showed that, regardless of age or reproductive developmental stage, bone density largely demonstrates familial resemblance and heritability. This scoping review informed the analysis of a pre-existing cohort of 39 paired youngadult daughters and menopause-aged mothers. The cohort data included health and reproductive history, current calcium intake, physical activity level, body composition, areal bone mineral density (aBMD) at the lumbar spine (LS), femoral neck (FN), total hip (TH), whole body (WB) from dual X-ray absorptiometry (DXA), and bone microarchitecture, cross-sectional area (CSA) and volumetric BMD (vBMD) at the radius and tibia from high-resolution quantitative computed tomography (HR-pQCT). No heritability was seen for DXA-derived aBMD or HR-pQCT-derived total vBMD, but there was for radial and tibial CSA and microarchitecture, and tibial vBMD. Tibial parameters were more heritable than radial, and CSA was more heritable than density or microarchitecture. The percentage of variance accounted for by lifestyle and heritability for aBMD was 10% to 45%, for radial parameters was 11% to 70% and for tibial parameters was 29% to 66%. Therefore, there is familial resemblance in bone health parameters between menopause-aged mothers and young-adult daughters.Item Open Access CHESS: Changes in Hormones with Exposure to Student Stress(2019-08-20) Crack, Laura Elizabeth; Doyle-Baker, Patricia K.; Murias, Juan M.; Lebrun, Constance MarieSalivary cortisol levels measure the acute stress response and this daily measurement occurs in two phases: the cortisol awakening response (CAR; 30 minutes after waking) and the diurnal cortisol response (the slope of the trend line associated with the remaining periodic samples throughout the day). Progesterone, one of two female sex hormones associated with the menstrual cycle (MC) is not well documented in terms of the stress cycle. The primary objective of the CHESS study was to prospectively investigate the impact of chronic stress (measured by the Student-Life Stress Inventory) on salivary cortisol and progesterone levels among female undergraduate students (N=19), while controlling for MC phase. Participants displayed blunted CAR, possible hypothalamic-pituitary-adrenal axis dysregulation manifested in irregular diurnal cortisol patterns, and changes in progesterone levels in response to academic stress. This finding provides a foundation for future studies to examine the relationship between cortisol and progesterone during times of stress.Item Open Access Examining Measures of Weight as Risk Factors for Sport-Related Injury in Adolescents(2016-07-20) Richmond, Sarah A.; Nettel-Aguirre, Alberto; Doyle-Baker, Patricia K.; Macpherson, Alison; Emery, Carolyn A.Objectives. To examine body mass index (BMI) and waist circumference (WC) as risk factors for sport injury in adolescents. Design. A secondary analysis of prospectively collected data from a pilot cluster randomized controlled trial. Methods. Adolescents () at the ages of 11–15 years from two Calgary junior high schools were included. BMI (kg/m2) and WC (cm) were measured from direct measures at baseline assessment. Categories (overweight/obese) were created using validated international (BMI) and national (WC) cut-off points. A Poisson regression analysis controlling for relevant covariates (sex, previous injury, sport participation, intervention group, and aerobic fitness level) estimated the risk of sport injury [incidence rate ratios (IRR) with 95% confidence intervals (CI)]. Results. There was an increased risk of time loss injury (IRR = 2.82, 95% CI: 1.01–8.04) and knee injury (IRR = 2.07, 95% CI: 1.00–6.94) in adolescents that were overweight/obese; however, increases in injury risk for all injury and lower extremity injury were not statistically significant. Estimates suggested a greater risk of time loss injury [IRR = 1.63 (95% CI: 0.93–2.47)] in adolescents with high measures of WC. Conclusions. There is an increased risk of time loss injury and knee injury in overweight/obese adolescents. Sport injury prevention training programs should include strategies that target all known risk factors for injury.Item Open Access Familial resemblance of bone health in maternal lineage pairs and triads: A scoping review protocol(2021-05-03) Boisvert, Nicole M.J.; Hayden, K. Alix; Doyle-Baker, Patricia K.Population: Maternal Pairs or Triads. Concept: Familial Resemblance. Context: Bone Health. Primary Question: What is the familial resemblance of bone health in pairs or triads within maternal biological lineage? Secondary Question: What is the correlation between bone health and bone health affecting behaviours of triads and pair within familial lineages?Item Open Access Female athletes’ decisions to use hormonal contraceptives: a scoping review protocol.(2024) Suarez Moreno, Paula; Van Den Berg, Carla; Hayden, K. Alix; Doyle-Baker, Patricia K.Female athletes from a variety of sports indicate a perceived impact of the menstrual cycle (MC) on their performance (Brown et al., 2021; Ekenros et al., 2022; Findlay et al., 2020). Female athletes often choose to use hormonal contraceptives (HC’s) and although their reasons vary, the most consistent one is related to the impact of the MC on performance and training. For example, in a study by Martin et al., (2018) a third of 145 combined oral contraceptive athlete users perceived that cycle manipulation to avoid menstruation can be considered a positive outcome of oral contraceptive use. Therefore, the objective of this scoping review is to investigate the extent of evidence associated with the reasons behind female athletes’ decision to use or discontinue use of hormonal contraceptives. The inclusion criteria included a) female (sex assigned at birth), b) athletes actively participating in competition, of which the majority are competing at least a regional level (Swann et al., 2015), c) sample is mostly age 18 years or older, d) discusses knowledge, reasons, perceptions, attitudes, beliefs of the athletes as related to their decisions regarding HC use and e) discusses history of hormonal contraceptive use either current or previous as an athlete. The JBI guidelines for scoping reviews found in the JBI Manual for Evidence Synthesis (2020) will be followed and this review will be reported in accordance with the PRISMA –SCr extension (Peters et al., 2020; Tricco et al., 2018).Item Open Access Friendship networks and physical activity and sedentary behavior among youth: a systematized review(BioMed Central, 2013-12-01) Sawka, Keri Jo; McCormack, Gavin R.; Nettel-Aguirre, Alberto; Hawe, Penelope; Doyle-Baker, Patricia K.Item Open Access Menstrual and Oral Contraceptive Phases Do Not Influence Submaximal and Maximal Responses to Exercise or Vascular Responsiveness at Rest(2020-04-20) Mattu, Anmol Trishia; Murias, Juan M.; MacInnis, Martin J.; Doyle-Baker, Patricia K.Endogenous and exogenous female reproductive hormones fluctuate across the respective menstrual and oral contraceptive cycle phases. Importantly, estrogen and progesterone are known to have numerous physiological effects, which are likely to have an impact on exercise outcomes. Current literature exploring the effects of the menstrual and oral contraceptive cycles on exercise responses is limited and remains inconclusive (1). Moreover, no previous studies have examined the within-cycle effects on muscle microvascular function at rest, which may provide important insight into the changes in oxygen delivery to active tissues during exercise across the cycle phases. Therefore, the objective of this thesis was to examine whether the menstrual or monophasic oral contraceptive cycle phases affect a wide variety of submaximal (oxygen uptake (V̇O2) kinetics, maximal lactate steady-state (MLSS)) and maximal (maximal oxygen uptake (V̇O2max), time-to-exhaustion (TTE)) responses to exercise, and vascular responsiveness of the lower limb microvasculature at rest in healthy, active women. During the follicular or inactive-pill phase and the luteal or active-pill phase of the menstrual or oral contraceptive cycle, respectively, 15 non-oral contraceptive users and 15 monophasic oral contraceptive users underwent a lower limb vascular occlusion test and performed one V̇O2 kinetics test; one ramp-incremental test to exhaustion; two to three 30-min constant-load cycling trials to determine the power output corresponding to MLSS, followed by a TTE trial. Menstrual cycle phases were verified using an ovulation test. Vascular responsiveness was assessed by calculating the near-infrared spectroscopy-derived muscle oxygen saturation (StO2) reperfusion slope and the post-occlusion StO2 area under the curve of the tibialis anterior muscle. The results suggest that the fluctuations of natural or synthetic hormones between the phases of the menstrual or oral contraceptive cycle, respectively, had no detectable effects on submaximal (V̇O2 kinetics, MLSS) and maximal (V̇O2max, TTE) exercise performance and lower limb microvascular reperfusion responses. Future research studies evaluating exercise performance or microvascular reperfusion should not avoid testing women solely based on the idea that the cycle phases may act as a confounding variable for their outcome measures.Item Open Access Motivations for use, user experience, and quality of menstrual cycle tracking mobile applications: A scoping review protocol(2023-07-05) Kazakoff, Alissa; Doroshuk, Marissa L.; Ganshorn, Heather; Doyle-Baker, Patricia K.Objective: This scoping review aims to comprehensively assess and describe the existing peerreviewed literature on motivations for use, user experience, and menstrual cycle app quality. Introduction: The global mHealth market is growing at an unprecedented rate and is expected to reach an estimated value of $18.7 billion by 2030 (Prophecy Market Insights, 2021). Tracking health and menstrual cycle metrics can empower individuals by increasing awareness and understanding of their menstrual cycle, being prepared for different cycle phases, contraception and fertility, improving health-related behaviours, and informing conversations with healthcare providers (Epstein et al., 2017; Levy & Romo-Avilés 2019; Karasneh et al., 2020; Adnan et al., 2021; Gonçalves et al., 2021). Recent studies have identified several different factors that render users more likely for continued app use. These include perceived personal and health benefits, app accuracy, usability, and user-friendly design (Karasneh et al, 2020; Schantz et al., 2021). Inclusion criteria: This scoping review will investigate the existing literature on menstrual cycle tracking app use and factors contributing to user retention, such as motivations for the use of the app, user experience, and app quality. All studies published in English after 2010 will be included related to investigating apps that serve a pre-menopausal menstrual cycle app user base, given that relevant data may be included even in studies where the scoping review research question is not the focus. Methods: The search strategy will aim to locate peer-reviewed studies. An initial limited search of MEDLINE was undertaken to identify articles on the topic. Studies published in English will be included. Studies published since 2010 will be included as that timeline is most appropriate for the introduction of smartphones and smartphone apps on the market. The databases to be searched include MEDLINE (Ovid platform), Embase (Ovid platform), Scopus (Elsevier), ACM Digital Library, and IEEE Xplore.Item Open Access Neuromuscular Deficits Following Anterior Cruciate Ligament Reconstruction with Hamstring Autograft: Implications for Rehabilitation and Return to Sport Testing(2020-07-16) Morris, Nathaniel; Herzog, Walter; Jordan, Matthew J.; Doyle-Baker, Patricia K.; Heard, MarkThe purpose of this study was to analyse the effects of anterior cruciate ligament reconstruction (ACLR) using the semitendinosus (ST) tendon autograft technique on knee flexor maximal torque, rate of torque development (RTD) and electromechanical delay (EMD) in athletes who had returned to competition, and to determine the relationship between knee flexor strength deficits and hamstring muscle cross-sectional area (CSA). Athletes with ACLR and non-injured, sex-matched, and sport-matched control athletes performed maximal voluntary contractions (MVC) of isometric knee flexion and extension to obtain maximal torque (TorqueMax) and maximal RTD (RTDMax) at 30°, 50°, 70°, 90° and 105° of knee flexion. Ultrasound imaging was used to measure muscle CSA of the knee flexors at 25%, 50%, and 75% of the anatomical distance from the knee crease to the ischial tuberosity. Deficits were found at all knee joint angles for Torquemax and more than 70° of knee flexion for knee flexor RTDmax when comparing the ACLR limb to the Contralateral limb. ST muscle CSA was smaller in the ACLR limb compared to the Contralateral limb at all measurement sites and strong to very strong correlations (r=0.6-0.9) were found between ST muscle CSA and knee flexor strength, especially for the distal ST CSA measurement site. No differences in EMD were found across joint angles, and no differences in ST EMD were found between limbs. The EMD was significantly elongated in the lateral hamstring muscles of the ACLR limb. These results suggest the importance of assessing and preserving ST muscle architecture following ACLR as well as restoring BF mechanical properties. Furthermore, graft choice should be made with consideration of the effect of ACLR on the torque-joint angle relationship and the specific strength requirements of the athlete’s sport.Item Open Access The progression of bone microarchitecture changes following an acute knee injury in young adults(2019-03-18) Kroker, Andres Mauricio; Boyd, Steven Kyle; Walker, Richard E. A.; Matyas, John Robert; Manske, Sarah Lynn; Van-Rietbergen, Bert; Doyle-Baker, Patricia K.Anterior cruciate ligament (ACL) tears are activity-related knee injuries associated with an elevated risk of developing post-traumatic osteoarthritis 10-20 years post-injury. Immediately after the injury bone mass is lost. This is followed by a recovery period, though full recovery is not achieved even years later. Due to a lack of appropriate imaging modalities, no information is available on how the underlying bone microarchitecture is affected. In addition, the effects of concurrent soft-tissue injuries, such as meniscus tears or traumatic bone marrow lesions, on the underlying bone microarchitecture in human knees are not known. In this thesis, a new method for in vivo assessment of bone microarchitecture of the human knee is introduced. Next, in two cross-sectional studies this technique is applied to populations that experienced unilateral ACL tears six to nine years earlier. Both studies revealed that bone is primarily affected in the femur of the injured knee. Trabecular bone mass is lower in the medial femur (-4.8% to -10.4%) while the subchondral bone plate is thicker in the lateral femur (9% to 29.6%) as compared to the contralateral knee. Further, the thicker subchondral bone plate is associated with surgical meniscus treatment (meniscectomy or repair) at the time of ligament reconstruction. In a year-long longitudinal study, the new imaging technique is applied to a cohort with acute unilateral ACL tears to investigate how early injury-induced bone changes affect microstructure. Immediately following the injury, trabecular bone is lost throughout the injured knee (-4.9% to -15.8%), driven by a loss of trabecular elements and increased trabecular separation. Concurrently, the subchondral bone plate of the lateral femur thins (-9%). The trabecular bone changes are further accelerated in traumatic bone marrow lesions (-18.2% to -20.6%). These findings show that while initial bone mass loss following the injury may recover six to nine years later (primarily in the tibia), the femur is affected long-term. The underlying structural changes are believed to be permanent, and while it is not known which individuals will develop osteoarthritis, limiting early injury-induced bone changes may reduce long-term risk of joint degradation.Item Open Access A Prospective Proof-of-Concept Study Evaluating the Influence of Patient Education on Knowledge, Attitudes, and Cardiac Rehabilitation Attendance among Patients with Coronary Artery Disease(2019-08-23) Williamson, Tamara Marie; Campbell, Tavis S.; Rouleau, Codie R.; King-Shier, Kathryn M.; Doyle-Baker, Patricia K.; von Ranson, Kristin M.Patient education (PE), delivered during cardiac rehabilitation (CR), aims to promote CR exercise attendance by imparting knowledge about coronary artery disease (CAD; medication, risk factors, etc.) and enhancing CR-related attitudes. This study evaluated the impact of PE on motivational treatment targets (CAD knowledge, CR attitudes), and CR exercise attendance. Adults (18+) with CAD referred to CR were recruited prior to attending PE. CAD knowledge and CR attitudes (perceived necessity/suitability, exercise concerns, barriers) were assessed pre/post-PE, and at 12-week follow-up. CR exercise attendance was obtained by chart review. Seventy-one patients (87% male) participated. CAD knowledge and perceived CR necessity improved pre- to post-PE; gains persisted at 12-weeks. Greater knowledge gains did not predict larger improvements in CR attitudes or increased exercise attendance. Whereas CR-based PE may be useful for improving CAD-related knowledge and perceived need for CR, more formative work is needed to determine whether PE can promote CR exercise attendance.Item Open Access Salivary and urinary methodology for ovulation and menstrual cycle phase detection among eumenorrheic females: A scoping review protocol(2022-05-03) Doroshuk, Marissa L.; Kazakoff, Alissa; Hayden, K. Alix; Doyle-Baker, Patricia K.Most females will experience variability in their menstrual cycle (MC) at some point across the reproductive lifespan (Bull et al., 2019). Current literature suggests that it is important for females to track MC regularity and ovulation occurrence as it is related to other health outcomes (Lynch et al., 2014). MC tracking and ovulation can be detected using a variety of methods (Allen et al., 2017). The gold standard for ovulation detection includes daily transvaginal ultrasonography and laparoscopic evaluation of the developing follicle until the point of rupture. These methods, however, can be costly, invasive, and have a large participant burden (Allen et al., 2017; Lynch et al., 2014). Therefore, accessible, and reliable methods of ovulation and MC phase detection are warranted. The study objective is to examine methods in the literature associated with salivary assay and urinary hormone testing for ovulation and menstrual cycle phase detection. Inclusion criteria for participants and defining characteristics consist of the following a) eumenorrheic females between 18 to 45 years of age, b) salivary and/or urinary hormone testing methods, c) menstrual cycle measurement, d) ovulation detection, and e) estradiol, progesterone, and/or luteinizing hormone (LH) measures. The proposed scoping review will be conducted in accordance with the JBI methodology for scoping reviews described in the JBI Manual for Evidence Synthesis (2020). The review will also cover the 2018 PRISMA reporting items for scoping review extensions (Tricco et al., 2018). Population: Eumenorrheic Females. Concept: Salivary and Urinary Hormone Testing Methods. Context: Ovulation and Menstrual Cycle Phase Detection PRIMARY QUESTION: What is the validity and reliability of salivary and urinary assay testing for female sex hormones in ovulation detection and menstrual cycle phase identification? SECONDARY QUESTION: What are the salivary and urinary protocols used to test female sex hormones and what ranges are considered within normal? TERTIARY QUESTION: Are salivary and urinary assays for female sex hormones (estrogen, progesterone, and luteinizing hormone) comparable to the gold standard, serum, in relation to the menstrual cycle?"Item Open Access STICK ITT - Study to Increase Current Knowledge of Injuries in Trampoline and Tumbling(2021-01-28) Downie, Sheila; Kenny, Sarah J.; Emery, Carolyn A.; Schneider, Kathryn J.; Doyle-Baker, Patricia K.; van Wyk, NadineObjectives: To examine incidence rates, severity, characteristics, mechanism and potential risk factors for injury in competitive Trampoline and Tumbling (T&T) athletes ages 8 to 25 years. Methods: Competitive T&T athletes were recruited from across Canada to complete an online questionnaire (e.g., demographics, one-year injury history, injury type and location). Injury was defined as an injury that kept the athlete from T&T training and/or competing for more than one day and/or required medical attention. Univariate Poisson regression analyses were used to estimate incidence rates (IR) and incidence rate ratios (IRR), controlling for cluster by club and offset by exposure hour. Differences in rates were estimated across level of competition (sub-elite/elite), sex (male/female), age (years), T&T experience (years) and exposure (training/competition hours). Descriptive statistics (medians, ranges, proportions, 95% confidence intervals) for athlete demographics and injury characteristics are reported. Results: A total of 132 athletes [89 female; median age=14 (range 10-24 years), 43 males; median age 15 (range 9-24)] from 25 clubs completed the survey with 65% reporting at least one T&T related injury in the previous year. A total of 135 injuries were reported (IR 2.01/1000 exposure hours 95%CI 1.69-2.39). The median time-loss was 30 days (range 0-482) and 125/135 (92.5%) of the injured athletes sought medical attention. The injury rate for elite athletes was 115 injuries/100 athletes/year (95% CI 89.4-143.1) and 92 injuries/100 athletes (95%CI 70.8-116.6) for sub-elite. The most common injury locations were the ankle [28% (24/135)] and head/face [18% (24/135)]. Ligament sprains [22% (30/135)] and concussion [17% (23/135)] were the most common injury type. Females reported significantly higher rate of injury than males [IRR 1.49 (95%CI 1.12-1.92)]. Conclusion: This study examined injury incidence in terms of exposure and found females were at greater rate of injury over their male counterparts. Athletes experience ankle, head (concussion) and overuse type injuries as they engage in competitive T&T. Additional prospective research is needed to inform the development of effective injury prevention strategies among these high-risk young athletes.Item Open Access The influences of skeletal muscle mitochondria and sex on critical torque and fatigue in humans(2022-08-17) McDougall, Rachel M.; MacInnis, Martin J.; Aboodarda, S. Jalal; Doyle-Baker, Patricia K.; Mitchell, Cameron J.Mitochondria provide ATP through oxidative phosphorylation (OXPHOS) to generate muscular force and maintain cellular homeostasis during exercise. The critical torque (CT) represents the highest intensity of intermittent isometric contractions that can be supported entirely by aerobic metabolism as well as a phase transition between distinct profiles of performance muscle fatigability (PMF) development. The purpose of this study was to investigate whether skeletal muscle mitochondrial content and sex were related to variation in CT and the magnitude of PMF induced by aerobic, small muscle mass exercise. Twelve females and 12 males matched for aerobic fitness underwent vastus lateralis muscle biopsy sampling to determine their myosin heavy chain (MHC) composition (i.e., fibre type), mitochondrial protein content, and citrate synthase (CS) activity. Once recovered, participants completed 3-4 intermittent isometric knee extension trials to task failure, including one trial at a fixed intensity for all participants, to determine CT and the curvature constant (W’), and two 30-min trials of intermittent isometric knee extensor exercise 10% below CT to assess PMF. The absolute CT and relative CT were not significantly different between males and females (p>0.05). There was no significant difference across sexes for the content of any OXPHOS proteins or CS activity (p>0.05); however, males had significantly lower proportions of MHC I compared to females (p=0.021). Multiple biomarkers of mitochondrial content were correlated with CT, and a few of these markers correlated with indices of fatigability at exercise intensities above CT, but none correlated with indices of fatigue below CT. Thirty minutes of isometric knee extensor exercise 10% below CT caused peripheral and central fatigue (p<0.05) for all variables, but males and females demonstrated similar declines in maximum voluntary contraction, potentiated twitch force, low- frequency fatigue, and voluntary activation (p>0.05). Results were similar for exercise performed above the CT. In summary, CT was correlated with skeletal muscle properties related to mitochondrial content in fitness-matched males and females, but CT and mitochondrial content were not different across sexes. Furthermore, the magnitude of PMF induced by exercise near the CT was also similar between sexes, and PMF was only related to skeletal muscle properties for exercise above the CT.Item Open Access The use of near-infrared spectroscopy for microvascular function assessment in healthy and with obesity individuals during normo- and hyperglycemia(2019-09-19) Nogueira Soares, Rogerio; Murias, Juan M.; Doyle-Baker, Patricia K.; Reimer, Raylene A.; Fletcher, Jared R.; MacDonald, Maureen JaneVascular function has been shown to be an important predictor for cardiovascular disease (CVD). Among others, postprandial hyperglycemia has been shown to be a risk factor for CVD that is associated with impaired vascular function. Among others, obesity is a comorbidity associated with vascular dysfunction. In addition to the detrimental effects of obesity per se on the vasculature, obesity is also linked to impairments in glucose uptake/metabolism by the skeletal muscle, which further expose these individuals to the deleterious effects of glucose on the vascular tree. Thus, the overall objectives of the current thesis were to: i) assess changes in lower limb microvascular responsiveness induced by hyperglycemia in lean and obese individuals by using the near-infrared spectroscopy (NIRS) combined with vascular occlusion test (VOT) technique (NIRS-VOT); ii) use NIRS-VOT to compare differences in lower limb microvascular responsiveness during normoglycemia and hyperglycemia in lean and obese individuals; iii) investigate upper and lower limbs microvascular function and oxidative metabolism responses to glucose ingestion in participants with obesity compared to their healthy lean counterparts; iv) investigate the relationship between changes in upstream brachial artery flow-mediated dilation (FMD) and NIRS-VOT-derived assessment of forearm microvascular function induced by glucose ingestion in these individuals. The main findings of the present thesis were that NIRS-VOT detected hyperglycemia and obesity-related differences in microvascular responsiveness. Additionally, although no differences in the forearm microvascular responses to glucose ingestion were found between these two groups, obese individuals had impaired brachial FMD during hyperglycemia. The findings also demonstrated a blunted leg muscle oxidative metabolism response to glucose ingestion in obese individuals. The current thesis highlights the importance of assessing limb and muscle specific effects of hyperglycemia and obesity.