Simon Bacon
Concordia University (Canada), Deparment of Exercise Science, Faculty Member
... Fusegawa et al., 1999; Rival et al., 1987), altering the release of antithrombotic and prothrombotic factors by endothelial cells (Kannel et al., 1987; Sambola et al., 2003; Smith et al., 1997) as well as altering fibrinolysis, the... more
... Fusegawa et al., 1999; Rival et al., 1987), altering the release of antithrombotic and prothrombotic factors by endothelial cells (Kannel et al., 1987; Sambola et al., 2003; Smith et al., 1997) as well as altering fibrinolysis, the process by which blood clots are broken down (Barua et ...
Asthma and obesity are frequently associated, and obesity has been considered a factor contributing to both an increase in severity of asthma and to its development. The present document summarizes the proceedings of a symposium held in... more
Asthma and obesity are frequently associated, and obesity has been considered a factor contributing to both an increase in severity of asthma and to its development. The present document summarizes the proceedings of a symposium held in Montreal, Quebec, on November 2, 2006, under the auspices of the Réseau en santé respiratoire du Fonds de la recherche en santé du Québec in collaboration with the McGill University - Strauss Severe Asthma Program, Université Laval (Quebec City) and Université de Montréal. It includes an overview of the various aspects of the relationships between asthma and obesity with regard to animal models; genetic, hormonal and physiological determinants; influence of comorbidities (eg, sleep apnea syndrome); epidemiology; clinical and psychological features; and management of asthma in the obese population.
Research Interests:
To identify key solutions that facilitate the prescription of long-term asthma controller and provision of written self-management plans by physicians. One hour individualized semistructured interviews were conducted with physicians.... more
To identify key solutions that facilitate the prescription of long-term asthma controller and provision of written self-management plans by physicians. One hour individualized semistructured interviews were conducted with physicians. Interviews were transcribed verbatim and analyzed independently by two trained qualitative researchers. A taxonomy of facilitators (contemplated solutions) and experienced solutions was achieved by consensus within the research team. Forty-two physicians (family physicians, pediatricians, emergency physicians, pulmonologists and allergists) were interviewed. The 867 facilitators and solutions, grouped in 10 categories, addressed three physician needs: support physicians in delivering optimal care (guideline dissemination, workplace culture, physician training and experience, physician attitudes toward optimal practice, tools and resources supporting physicians' decision making); assist patients with following recommendations (patient characteristics...
Research Interests:
The vasovagal response (VVR) is a common medical problem, complicating and deterring people from various procedures. It is an unusual stress response given the widespread decreases in physiological activity. Nevertheless, VVR involves... more
The vasovagal response (VVR) is a common medical problem, complicating and deterring people from various procedures. It is an unusual stress response given the widespread decreases in physiological activity. Nevertheless, VVR involves processes similar to those observed during episodes of strong emotions and pain. We hypothesized that heightened perceived control would reduce symptoms of VVR. Eighty-two young adults were randomly assigned to perceived control or no perceived control conditions during exposure to a stimulus video of a mitral valve surgery, known to trigger VVR in non-medical personnel. Perceived control was manipulated by allowing some participants to specify a break time, though all received equivalent breaks. Outcomes included subjective symptoms of VVR, anxiety, blood pressure, heart rate, and other measures derived from impedance cardiography. Compared to participants with perceived control, participants with no perceived control reported significantly more vasov...
Research Interests:
Increased body weight has been associated with worse prognoses for many chronic diseases; however, this relationship is less clear in patients with chronic obstructive pulmonary disease (COPD), with underweight patients experiencing... more
Increased body weight has been associated with worse prognoses for many chronic diseases; however, this relationship is less clear in patients with chronic obstructive pulmonary disease (COPD), with underweight patients experiencing higher morbidity than normal or overweight patients. To assess the impact of body mass index (BMI) on the risk for COPD exacerbations. The present study included 115 patients with stable COPD (53% women; mean [± SD] age 67±8 years). Height and weight were measured to calculate BMI. Patients were followed for a mean of 1.8±0.8 years to assess the prospective risk of inpatient-treated exacerbations and outpatient-treated exacerbations, all of which were verified by chart review. Cox regression models revealed that underweight patients were at greater risk for inhospital-treated exacerbations (RR 2.93 [95% CI 1.27 to 6.76) relative to normal weight patients. However, overweight (RR 0.59 [95% CI 0.33 to 1.57) and obese (RR 0.99 [95% CI 0.53 to 1.86]) patient...
Research Interests:
exacerbations are common in chronic obstructive pulmonary disease (COPD) and contribute significantly to COPD morbidity and mortality. COPD is also associated with high levels of psychological distress, which has been shown to be... more
exacerbations are common in chronic obstructive pulmonary disease (COPD) and contribute significantly to COPD morbidity and mortality. COPD is also associated with high levels of psychological distress, which has been shown to be associated with higher exacerbation rates. However, the existing literature on the association between psychological distress and exacerbation risk remains largely misunderstood. to critically review the current literature on the association between psychological distress (defined as anxiety and depressive symptoms or anxiety and depressive disorders) and COPD exacerbations in COPD patients, to highlight the limitations of the existing literature, and to provide recommendations for future research. a critical review of English-language peer-reviewed longitudinal and retrospective studies was conducted. The Ovid portal to Medline, EMBASE, and PsycINFO databases were accessed. some acceptable evidence suggested that psychological distress confers greater risk...
Research Interests:
Forearm Endothelial Function (FEF) is a marker that has been shown to discriminate patients with cardiovascular disease (CVD). FEF has been assessed using several parameters: the Rate of Uptake Ratio (RUR), EWUR (Elbow-to-Wrist Uptake... more
Forearm Endothelial Function (FEF) is a marker that has been shown to discriminate patients with cardiovascular disease (CVD). FEF has been assessed using several parameters: the Rate of Uptake Ratio (RUR), EWUR (Elbow-to-Wrist Uptake Ratio) and EWRUR (Elbow-to-Wrist Relative Uptake Ratio). However, the modeling functions of FEF require more robust models. The present study was designed to compare an empirical method with quantitative modeling techniques to better estimate the physiological parameters and understand the complex dynamic processes. The fitted time activity curves of the forearms, estimating blood and muscle components, were assessed using both an empirical method and a two-compartment model. Although correlational analyses suggested a good correlation between the methods for RUR (r=.90) and EWUR (r=.79), but not EWRUR (r=.34), Altman-Bland plots found poor agreement between the methods for all 3 parameters. These results indicate that there is a large discrepancy betw...
Research Interests:
Research Interests:
To identify key solutions that facilitate the prescription of long-term asthma controller and provision of written self-management plans by physicians. One hour individualized semistructured interviews were conducted with physicians.... more
To identify key solutions that facilitate the prescription of long-term asthma controller and provision of written self-management plans by physicians. One hour individualized semistructured interviews were conducted with physicians. Interviews were transcribed verbatim and analyzed independently by two trained qualitative researchers. A taxonomy of facilitators (contemplated solutions) and experienced solutions was achieved by consensus within the research team. Forty-two physicians (family physicians, pediatricians, emergency physicians, pulmonologists and allergists) were interviewed. The 867 facilitators and solutions, grouped in 10 categories, addressed three physician needs: support physicians in delivering optimal care (guideline dissemination, workplace culture, physician training and experience, physician attitudes toward optimal practice, tools and resources supporting physicians' decision making); assist patients with following recommendations (patient characteristics...
Research Interests:
... K. Lavoie , S. Bacon , M. Joseph , M. Labrecque H. Favreau1 1 2 3 4 University of Quebec in Montreal (UQAM), Montréal, Canada, Concordia University, Montreal, Canada, McGill University, Montreal, 1 2 3 Canada, Hôpital du Sacré-Coeur... more
... K. Lavoie , S. Bacon , M. Joseph , M. Labrecque H. Favreau1 1 2 3 4 University of Quebec in Montreal (UQAM), Montréal, Canada, Concordia University, Montreal, Canada, McGill University, Montreal, 1 2 3 Canada, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada 4 ...
Research Interests:
Research Interests:
Marginal structural models are commonly used to estimate the causal effect of a time-varying treatment in presence of time-dependent confounding. When fitting an MSM to data, the analyst must specify both the structural model for the... more
Marginal structural models are commonly used to estimate the causal effect of a time-varying treatment in presence of time-dependent confounding. When fitting an MSM to data, the analyst must specify both the structural model for the outcome and the treatment models for the inverse-probability-of-treatment weights. The use of stabilized weights is recommended because they are generally less variable than the standard weights. In this paper, we are concerned with the use of the common stabilized weights when the structural model is specified to only consider partial treatment history, such as the current or most recent treatments. We present various examples of settings where these stabilized weights yield biased inferences while the standard weights do not. These issues are first investigated on the basis of simulated data and subsequently exemplified using data from the Honolulu Heart Program. Unlike common stabilized weights, we find that basic stabilized weights offer some protec...
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High blood pressure (BP) is a major health problem in the US, affecting more than 50 million people. Although high BP is among the most common reasons for outpatient visits, BP control is often inadequate. It is well established that BP... more
High blood pressure (BP) is a major health problem in the US, affecting more than 50 million people. Although high BP is among the most common reasons for outpatient visits, BP control is often inadequate. It is well established that BP can be lowered pharmacologically in hypertensive individuals; however, anti-hypertensive medications are not effective for everyone, and may be costly and result in adverse effects that impair quality of life and reduce adherence. Moreover, abnormalities associated with high BP, such as insulin resistance and hyperlipidaemia, may persist or may even be exacerbated by some anti-hypertensive medications. Consequently, there has been a great deal of interest in the development and application of behavioural interventions in the management of high BP. The main behavioural interventions that are recommended to reduce BP are exercise and the Dietary Approaches to Stop Hypertension (DASH) diet. Weight loss is also recommended for BP reduction in overweight ...
Research Interests:
Impaired endothelial function has been shown to limit exercise in coronary artery disease (CAD) patients and has been implicated in myocardial ischemia. However, the association of endothelial function and ischemia on peak exercise oxygen... more
Impaired endothelial function has been shown to limit exercise in coronary artery disease (CAD) patients and has been implicated in myocardial ischemia. However, the association of endothelial function and ischemia on peak exercise oxygen consumption (VO(2)) has not been previously reported. A total of 116 CAD patients underwent standard exercise stress testing, during which VO(2) was measured. On a separate day, endothelial-dependent and -independent function were assessed by ultrasound using flow-mediated arterial vasodilation (FMD) and sublingual glyceryl trinitrate administration (GTNMD) of the brachial artery. Patients with exercise-induced myocardial ischemia had lower FMD than nonischemic patients (3.64 ± 0.57 versus 4.98 ± 0.36, P = .050), but there was no difference in GTNMD (14.11 ± 0.99 versus 15.47 ± 0.63, P = .249). Analyses revealed that both FMD (P = .006) and GTNMD (P = .019) were related to peak VO(2). However, neither the presence of ischemia (P = .860) nor the int...