Browsing by Author "Friedenreich, Christine Marthe"

Now showing 1 - 11 of 11
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    A case-control study of dietary patterns and endometrial cancer risk
    (2009) Biel, Rita; Friedenreich, Christine Marthe
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    Adiposity and mammographic density
    (2006) Woolcott, Christy Gwen; Cook, Linda S.; Friedenreich, Christine Marthe
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    Association Between Lifetime Physical Activity and Cognitive Functioning in Middle-aged and Older Community Dwelling Adults: Results from the Brain in Motion Study
    (2015-09-30) Gill, Stephanie; Poulin, Marc; Friedenreich, Christine Marthe
    Objective: Is total lifetime physical activity (PA) associated with better cognitive functioning with aging and does cerebrovascular function mediates this association? Methods: 226 community dwelling middle-aged and older adults completed the Lifetime Total PA Questionnaire, underwent neuropsychological and cerebrovascular blood flow testing. Multiple robust linear regressions were used to model the associations between lifetime PA and global cognition. Mediation analysis was used to assess the effect of cerebrovascular measures on the association between lifetime PA and global cognition. Results: Better cognitive performance was associated with higher lifetime PA (p=0.045), recreational PA (p=0.018), vigorous intensity PA (p=0.004), PA between the ages of 0-20 years (p=0.028), and the ages of 21-35 years (p<0.0001). Cerebrovascular measures partially mediated the relation between current fitness and cognition. Conclusion: This study revealed significant associations between higher levels of lifetime PA and better cognitive function. Cerebrovascular function partially mediated the relation between current fitness and global cognition.
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    Associations between the Neighbourhood Built Environment and Walking
    (2018-07-11) Farkas, Brenlea Jenelle Marie; McCormack, Gavin Robert; Friedenreich, Christine Marthe; Nettel-Aguirre, Alberto
    Physical inactivity is a risk factor for overweight and obesity, type II diabetes, cardiovascular disease, depression, and breast/colon cancer. Despite the known benefits of physical activity, many Canadian adults do not achieve the recommended levels of physical activity necessary to obtain optimal health. Evidence suggests that built characteristics within neighbourhoods are associated with physical activity, and in particular walking. There is growing policy interest in neighbourhood interventions to increase physical activity, specifically walking, suggesting the need for a synthesis of Canadian evidence to better inform local urban planning. There were two main aims of this thesis. The first was to provide a better understanding of how the built environment influences walking behaviour in Canadian adults. The second was to contribute to this body of evidence by studying the associations between individual characteristics of the neighbourhood environment and walking outcomes. A systematized review of Canadian evidence supported findings from other reviews, suggesting that overall walkability, land-use mix, and proximity to destinations are important features of the built environment for promoting transportation walking. Built environment associations with recreation walking are less clear. The systematized review also identified gaps in the current body of research, some of which were addressed in the analytic component of this thesis. A quantitative data analysis for a sample of Canadian adults living in 12 neighbourhoods of varying urban form and socioeconomic status in Calgary, Canada did not find any statistically significant associations between individual characteristics of the neighbourhood built environment and recreation walking or transportation walking, after adjusting for residential self-selection, sociodemographic characteristics, and neighbourhood socioeconomic status. Further research is needed to better understand how individual characteristics of the neighbourhood built environment facilitate or inhibit walking in order to better inform urban planning and public health policy.
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    Convergent Validity and Test Re-Test Reliability of Two Accelerometers for Measuring Physical Activity and Sedentary Behaviour in a Healthy Population of Older Women
    (2014-05-02) Pfister, Ted; Friedenreich, Christine Marthe
    A central aspect of physical activity (PA) and sedentary behavior (SB) research is accurate assessment in the context of disease outcomes. The primary objectives were to evaluate the convergent validity and test-retest reliability of the ActiGraph® GT3X+ (AG) and ActivPAL3® (AP) accelerometers. Participants were from the Breast Cancer and Exercise Trial in Alberta (n=225) and wore both monitors concurrently during waking hours for seven days. When comparing AG Vector Magnitude (VM) and Vertical axis (VT) with AP, all measures of PA were statistically significantly different with the exception of moderate activity between AG (VM) and AP (p=0.15). No statistically significant difference occurred between AP and AG (VM) or (VT) for time in SB with p=0.48 and p=0.27, respectively. Intraclass correlation coefficients (ICC) ranged from 0.66 to 0.93 for moderate and sedentary time by AG (VT), respectively. Despite small mean differences at the group level, limits of agreement suggest these devices cannot be used interchangeably.
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    Determinants of Physical Activity in a Cohort of Prostate Cancer Survivors
    (2018-07-24) Stone, Chelsea Rose; Friedenreich, Christine Marthe; Courneya, Kerry S.; McGregor, S. Elizabeth; Li, Haocheng
    Background: Physical activity has been shown to improve overall health, improve cancer outcomes and reduce all-cause mortality as well as prostate cancer specific mortality after diagnosis, however a cancer diagnosis can often cause a change in physical activity patterns. Current guidelines recommend 150 minutes per week of physical activity and the determinants of meeting these guidelines before and after a prostate cancer diagnosis are widely unknown. Objectives: Our first objective was to examine the determinants of meeting physical activity guidelines at pre-diagnosis and three time-points post-diagnosis. Our second objective was to examine the determinants of patterns of meeting guidelines from pre-diagnosis to two years post-diagnosis. The final objective was to examine determinants of patterns of long-term physical activity behaviours from pre-diagnosis to an average measure of post-diagnosis physical activity. Methods: This prospective cohort study included 830 prostate cancer patients who participated in a population-based case-control study between November 1997 and December 2000 in Alberta, Canada. Pre-diagnosis activity levels were self-reported at diagnosis and again at three time points post-diagnosis. Demographic, quality of life and lifestyle variables were collected by questionnaires, while medical chart abstractions were performed to capture clinical variables. Results: Active smoking status, poor physical health and rural living location were commonly found to be statistically significantly associated with failing to meet physical activity guidelines in cross-sectional analyses and in analyses examining patterns of behaviour from pre- to post-diagnosis. Conclusions: Demographic, health and lifestyle variables are associated with meeting or not meeting physical activity guidelines from pre-diagnosis to post-diagnosis. Programming should be aimed at offering survivors support to overcome determinants associated with decline in physical activity patterns.
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    Development and Assessment of a Neighbourhood International Physical Activity Questionnaire (N-IPAQ)
    (2018-06-08) Frehlich, Levi Colt; McCormack, Gavin Robert; Nettel-Aguirre, Alberto; Friedenreich, Christine Marthe
    Physical activity is a cornerstone for health, moreover, physical inactivity is independently associated with poor health outcomes. The neighbourhood built environment provides a unique opportunity to address both physical activity and inactivity. Higher walkable neighbourhoods have consistently shown increases in active transportation; however, many of these outcomes have been supported using non-context specific tools (i.e., measures of general physical activity). This project addresses this research gap by developing and testing a neighbourhood specific physical activity questionnaire (N-IPAQ). The N-IPAQ demonstrated reliability through self-administered paper and online formats. Moreover, the N-IPAQ demonstrated construct and concurrent validity using objective measures of neighborhood and physical activity. The N-IPAQ was also able to distinguish physical activity differences between high and low walkable neighborhoods. The use of the N-IPAQ in larger population based research could therefore better elucidate the specific built environment characteristics that foster or hinder physical activity.
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    Influence of dietary antioxidant and oxidant intake on leukocyte telomere length
    (2017) Mickle, Alexis Tory; Friedenreich, Christine Marthe; Brenner, Darren; Beattie, Tara; Williamson, Tyler
    Background: Telomeric DNA is highly susceptible to oxidative damage, and dietary habits may impact telomere attrition rates through the mediation of oxidative stress and chronic inflammation. Objectives: To examine the association between both the Dietary Inflammatory Index 2010 (DII) and the Alternative Healthy Eating Index 2010 (AHEI) with relative Leukocyte Telomere Length. Design: We conducted a cross-sectional analysis using baseline data from 301 healthy, inactive post-menopausal women. Diet quality was estimated using DII and AHEI scores derived from food frequency questionnaire data. LTL was measured using qPCR. Associations were examined using multivariable adjusted linear regression. Results: No statistically significant associations were detected between AHEI (p=0.20) or DII (p=0.91) and LTL in multivariable adjusted models. Conclusions: AHEI or DII scores were not related to LTL in this population. Future research is warranted to enhance understanding regarding the molecular processes involved in the relations between diet, telomere length and chronic disease risk.
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    A population-based study of the associations between neighbourhood walkability and different types of physical activity in Canadian men and women
    (2019-11-05) Nichani, Vikram; Vena, Jennifer E.; Friedenreich, Christine Marthe; Christie, Chelsea; McCormack, Gavin R.
    Few Canadian studies have examined whether or not associations between neighbourhood walkability and physical activity differ by sex. We estimated associations between perceived neighbourhood walkability and physical activity among Canadian men and women. This study included cross-sectional survey data from participants in ‘Alberta’s Tomorrow Project’ (Canada; n=14,078), a longitudinal cohort study. The survey included socio-demographic items as well as the International Physical Activity Questionnaire (IPAQ) and the abbreviated Neighbourhood Environment Walkability Scale (NEWS-A), which captured perceived neighbourhood built characteristics. We computed subscale and overall walkability scores from NEWS-A responses. Covariate-adjusted generalized linear models estimated the associations of participation (≥10 minutes/week) and minutes of different types of physical activity, including transportation walking (TW), leisure walking (LW), moderate-intensity physical activity (MPA), and vigorous-intensity physical activity (VPA) with walkability scores. Walkability was positively associated with participation in TW, LW, MPA and VPA and minutes of TW, LW, and VPA. Among men, a negative association was found between street connectivity and VPA participation. Additionally, crime safety was negatively associated with VPA minutes among men. Among women, pedestrian infrastructure was positively associated with LW participation and overall walkability was positively associated with VPA minutes. Notably, overall walkability was positively associated with LW participation among men and women. Different perceived neighbourhood walkability characteristics might be associated with participation and time spent in different types of physical activity among men and women living in Alberta. Interventions designed to modify perceptions of neighbourhood walkability might influence initiation or maintenance of different types of physical activity.
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    Quality of Life After Prostate Cancer Diagnosis: A Longitudinal Prospective Cohort Study in Alberta, Canada
    (2016) Farris, Megan; Friedenreich, Christine Marthe; Courneya, Kerry; Kopciuk, Karen; McGregor, S. Elizabeth
    OBJECTIVES: First, we examined the associations of post-diagnosis physical activity and change in pre-diagnosis physical activity on quality of life (QoL) in prostate cancer survivors. Then, we identified post-prostate cancer diagnosis QoL trajectories over time in the population. METHODS: 830 prostate cancer survivors were derived from a prior case-control study where information at diagnosis was collected, then survivors were re-consented into a follow-up study. Three repeated measurements of physical activity and QoL were undertaken post-diagnosis. RESULTS: We observed improvements in physical QoL in prostate cancer survivors who maintained or adopted higher levels of physical activity pre- and post-diagnosis, according to the cancer prevention physical activity guidelines compared to those who were non-exercisers. In the trajectory analysis, three physical and three mental trajectory groups were identified. CONCLUSION: With additional research, these established trajectory groups may help healthcare professionals in improving treatment and follow-up for this population of prostate cancer survivors.
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