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Maternal Obesity Drives Functional Alterations in Uterine NK Cells

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2016-07-21
Abstract: 

Over one-fifth of North American women of childbearing age are obese, putting these women at risk for a variety of detrimental chronic diseases. In addition, obesity increases the risk for developing major complications during pregnancy. The mechanisms by which obesity contributes to pregnancy complications and loss remain unknown. Increasing evidence indicates that obesity results in major changes to adipose tissue immune cell composition and function; whether or not obesity also affects immune function in the uterus has not been explored. Here we investigated the effect of obesity on uterine natural killer (uNK) cells, which are essential for uterine artery remodeling and placental development. Using a cohort of obese or lean women, we found that obesity led to a significant reduction in uNK cell numbers accompanied with impaired uterine artery remodeling. uNK cells isolated from obese women had altered expression of genes and pathways associated with extracellular matrix remodeling and growth factor signaling. Specifically, uNK cells were hyper-responsive to PDGF, resulting in overexpression of decorin. Functionally, decorin strongly inhibited placental development by limiting trophoblast survival. Together, these findings establish a potentially new link between obesity and poor pregnancy outcomes, and indicate that obesity-driven changes to uterine-resident immune cells critically impair placental development.

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Article
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Impacts of Bicycle Infrastructure in Mid-Sized Cities (IBIMS): protocol for a natural experiment study in three Canadian cities

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-01-21
Abstract: 

Introduction: Bicycling is promoted as a transportation and population health strategy globally. Yet bicycling has low uptake in North America (1%–2% of trips) compared with European bicycling cities (15%–40% of trips) and shows marked sex and age trends. Safety concerns due to collisions with motor vehicles are primary barriers.  To attract the broader population to bicycling, many cities are making investments in bicycle infrastructure. These interventions hold promise for improving population health given the potential for increased physical activity and improved safety, but such outcomes have been largely unstudied. In 2016, the City of Victoria, Canada, committed to build a connected network of infrastructure that separates bicycles from motor vehicles, designed to attract people of ‘all ages and abilities’ to bicycling.  This natural experiment study examines the impacts of the City of Victoria’s investment in a bicycle network on active travel and safety outcomes. The specific objectives are to (1) estimate changes in active travel, perceived safety and bicycle safety incidents; (2) analyse spatial inequities in access to bicycle infrastructure and safety incidents; and (3) assess health-related economic benefits.  Methods and analysis: The study is in three Canadian cities (intervention: Victoria; comparison: Kelowna, Halifax). We will administer population-based surveys in 2016, 2018 and 2021 (1000 people/city). The primary outcome is the proportion of people reporting bicycling. Secondary outcomes are perceived safety and bicycle safety incidents. Spatial analyses will compare the distribution of bicycle infrastructure and bicycle safety incidents across neighbourhoods and across time. We will also calculate the economic benefits of bicycling using WHO’s Health Economic Assessment Tool.  Ethics and dissemination: This study received approval from the Simon Fraser University Office of Research Ethics (study no. 2016s0401). Findings will be disseminated via a website, presentations to stakeholders, at academic conferences and through peer-reviewed journal articles

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Article
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Evaluation of the Impact of a Public Bicycle Share Program on Population Bicycling in Vancouver, BC

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-10-03
Abstract: 

Public bicycle share programs have been implemented in cities around the world to encourage bicycling. However, there are limited evaluations of the impact of these programs on bicycling at the population level. This study examined the impact of a public bicycle share program on bicycling amongst residents of Vancouver, BC. Using an online panel, we surveyed a population-based sample of Vancouver residents three times: prior to the implementation of the public bicycle share program (T0, October 2015, n=1111); in the early phase of implementation (T1, October 2016, n=995); and one-year post implementation (T2, October 2017, n=966). We used difference in differences estimation to assess whether there was an increase in bicycling amongst those living and/or working in close proximity (≤500 m) to Vancouver's Mobi by Shaw Go public bicycle share program, compared to those living and working outside this area. Results suggest that only living or only working inside the bicycle share service area was not associated with increases in bicycling at T1 or T2 relative to those outside the service area. Both living and working inside the bicycle share service area was associated with increases in bicycling at T1 (OR: 2.26, 95% CI: 1.07, 4.80), however not at T2 (OR: 1.37, 95% CI: 0.67, 2.83). These findings indicate that the implementation of a public bicycle share program may have a greater effect on bicycling for residents who both live and work within the service area, although this effect may not be sustained over time. 

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Article
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Aeroallergens in Canada: Distribution, Public Health Impacts, and Opportunities for Prevention

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-07-25
Abstract: 

Aeroallergens occur naturally in the environment and are widely dispersed across Canada, yet their public health implications are not well-understood. This review intends to provide a scientific and public health-oriented perspective on aeroallergens in Canada: their distribution, health impacts, and new developments including the effects of climate change and the potential role of aeroallergens in the development of allergies and asthma. The review also describes anthropogenic effects on plant distribution and diversity, and how aeroallergens interact with other environmental elements, such as air pollution and weather events. Increased understanding of the relationships between aeroallergens and health will enhance our ability to provide accurate information, improve preventive measures and provide timely treatments for affected populations.

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Article
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Strategies for Recruiting Women Living with Human Immunodeficiency Virus in Community-Based Research: Lessons from Canada

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-04
Abstract: 

Objectives: This study sought to describe the recruitment of women living with HIV (WLWH) into the community-based Canadian HIV Women’s Sexual and Reproductive Health Cohort Study (CHIWOS), because women are underrepresented in HIV research.

Methods: There were 1,424 WLWH were enrolled from British Columbia, Ontario, and Québec, who completed detailed questionnaires administered by peer research associates (PRAs; WLWH with research training). During screening, participants were asked: “How did you hear about the study?” We describe recruitment strategies by subpopulation and offer reflections on challenges and successes.

Results: Of 1,131 participants with complete data, 40% identified as White, 33% African/Caribbean/Black, and 19% Indigenous. The median age was 45 years (interquartile range, 37–51) and 4% identified as trans women. Overall, 35% were recruited through PRAs/peers, 34% clinics, and 19% AIDS service organizations (ASOs). PRAs/peers were the predominant recruitment method in Ontario (49%), compared with clinics in British Columbia (40%), and Québec (43%). Nationally, PRAs/peers were more successful in recruiting WLWH commonly considered to be “harder to reach” (e.g., women identifying as trans, using drugs, not receiving HIV care). Clinics were more effective in recruiting younger women (16–29 years) and women not using ASOs. Recruitment challenges centered on engaging these harder to reach women. Successes included hiring PRAs who built participant trust, linking with clinics to reach women isolated from HIV communities, involving outreach workers to engage street-involved women, and disseminating study information to diverse stakeholders.

Conclusions: Having multiple approaches, engaging a diverse team of PRAs, ensuring flexibility, and cultivating reciprocal relationships with community stakeholders were key to recruiting a diverse and representative sample of WLWH.

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Article
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Cannabis Use Is Associated with Lower Rates of Initiation of Injection Drug Use Among Street-Involved Youth: A Longitudinal Analysis

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-02-12
Abstract: 

Introduction and Aims: Street-involved youth are known to be at elevated risk of initiating injection drug use. However, the impact of so-called “gateway” drugs, such as cannabis, on injection initiation is unknown. The objective of this study was to examine the association between cannabis use and initiation of injection drug use among a prospective cohort of street-involved youth in Vancouver, Canada.

 

Design and Methods: Data for this study were collected from the At-Risk Youth Study (ARYS). From September 2005 to May 2015, participants aged 14-26 who reported illicit drug use were recruited into this open prospective cohort study. An extended Cox regression model with time-updated covariates was used to identify factors independently associated with injection initiation.

 

Results: During the study period 481 street-involved youth were included in this study. Of these, 228 (47.4%) reported at least daily cannabis use, and 103 (21.4%) initiated injection drug use. In a multivariable analysis, ≥ daily cannabis use was associated with slower rates of injection initiation (Adjusted Relative Hazard [ARH]: 0.66, 95% Confidence Interval [CI]: 0.45 – 0.98; p = 0.038). Subanalyses revealed that cannabis use was negatively associated with initiation of injection stimulants but not initiation of injection opioids.

 

Discussion and Conclusions: Given the expansion of cannabis legalization throughout North America, it is encouraging that cannabis use was associated with slower time to initiation of injection drug use in this cohort. This finding challenges the view of cannabis as a gateway substance that precipitates the progression to using harder and more addictive drugs.

 

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Article
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Increasing Diversion of Methadone in Vancouver, Canada, 2005-2015

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-11-28
Abstract: 

Background and Aim: Although methadone, an opioid agonist, has been an effective medication used to treat opioid use disorder for over 40 years, recent studies have found that methadone was identified in more than a quarter of prescription opioid-related deaths among people who use illicit drugs in Vancouver, Canada. Thus, we sought to longitudinally examine the availability of diverted methadone among people who inject drugs (PWID).

Design and Methods: Data were collected from three prospective cohorts of PWID in Vancouver, Canada between December 2005 and May 2015. Multivariable generalized estimating equation logistic regression was used to identify temporal trends in the immediate availability of diverted methadone (defined as the ability to acquire illicit methadone in <10 minutes).

Results: A total of 2092 participants, including 727 (34.8%) women, were included in the present study. In the multivariable analyses after adjusting for a range of potential confounders, later calendar year (adjusted odds ratio [AOR] = 1.21 per year; 95% confidence interval [CI]: 1.19–1.23) was independently and positively associated with reporting immediate availability of diverted methadone.

Conclusions: We observed a significant increase in the reported availability of diverted methadone among PWID over a ten-year follow-up period. Further research is needed to identify strategies to limit methadone diversion and assess the impact of alternative medications that are equally effective but safer, such as buprenorphine/naloxone.

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Article
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The Costs of Crime Associated with Stimulant Use in a Canadian Setting

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-09-14
Abstract: 

Background: Costs attributable to criminal activity are a major component of the economic burden of substance use disorders, yet there is a paucity of empirical evidence on this topic. Our aim was to estimate the costs of crime associated with different forms and intensities of stimulant use.

Methods: Retrospective cohort study, including individuals from three prospective cohorts in Vancouver, Canada, measured biannually (2011-2015), reporting stimulant use at baseline assessment. Monthly crime costs included policing, court, corrections, and criminal victimization (2016 CAD). We estimated monthly crime costs associated with mutually exclusive categories of crack, cocaine, methamphetamine, and polystimulant use, stratified by daily/non-daily use, relative to stimulant abstinence, as well as the independent effects of treatment (opioid agonist (OAT) and other addiction treatment). We used a two part model, capturing the probability of criminal activity and costs of crime with generalized linear logistic and gamma regression models, respectively, controlling for age, gender, education, homelessness, mental health issues, employment, prior incarceration, alcohol and opioid use.

Results: The study sample included 1,599 individuals (median age 39, 65.9% male) assessed over 5299 biannual interviews. Estimates of associated monthly crime costs ranged from $5449 [95%C.I.: $2180, $8719] for non-daily polystimulant use, to $8893 [$4196, id="mce_marker"3,589] for daily polystimulant use. Cost differences between daily/non-daily use, injection/non-injection, and stimulant type were not statistically significant. Drug treatment was not associated with lower monthly crime costs in our sample.

Conclusions: Substantial crime-related costs were associated with stimulant use, emphasizing the urgency for development and implementation of efficacious treatment regimens.

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Article
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Supporting The Sexual Rights of Women Living With HIV: A Critical Analysis of Sexual Satisfaction and Pleasure Across Five Relationship Types

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-04-06
Abstract: 

In the context of HIV, a focus on protecting others has overridden concern about women’s own sexual wellbeing. Drawing on feminist theories, we measured sexual satisfaction and pleasure across five relationship types among women living with HIV in Canada. Of the 1,230 women surveyed, 38.1% were completely or very satisfied with their sexual life, while 31.0% and 30.9% were reasonably or not very/not at all satisfied, respectively. Among those reporting recent sexual experiences (n=675), 41.3% always felt pleasure, with the rest reporting usually/sometimes (38.7%) or seldom/not at all (20.0%). Sex did not equate with satisfaction or pleasure, as some women were completely satisfied without sex while others were having sex without reporting pleasure. After adjusting for confounding factors, such as education, violence, depression, sex work, antiretroviral therapy, and provider discussions about transmission risk, women in long-term/happy relationships (characterized by higher levels of love, greater physical and emotional intimacy, more equitable relationship power, and mainly HIV-negative partners) had increased odds of sexual satisfaction and pleasure relative to women in all other relational contexts. Those in relationships without sex also reported higher satisfaction ratings than women in some sexual relationships. Findings put focus on women’s rights, which are critical to overall well-being.

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Article
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The Importance of Informational, Clinical and Personal Support in Patient Experience with Total Knee Replacement: A Qualitative Investigation

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-03-24
Abstract: 

Background: Total knee arthroplasty (TKA) is the most frequently performed joint replacement surgery in North America. Patient perspectives on TKA have been investigated in various ways, including finding as many as 20% of TKA patients are dissatisfied with their surgical outcomes. Understanding the patient experience with TKA broadly and in relation to patient satisfaction is a key gap in existing literature.

 Methods: We report on the qualitative component of a mixed methods prospective cohort study examining patient experience and satisfaction post-TKA for adults in British Columbia, Canada. Data collection consisted of 45 in-depth interviews about individuals’ knee surgery experiences conducted eight months after surgery. Analysis consisted of thematic coding by multiple coders.

 Results: Participants’ descriptions of their TKA experiences were primarily concerned with support, or the provision of aid and assistance. Support was insufficient when their expectations of support were not met; unmet support expectations led to an overall negative TKA experience. Support operated in three key domains: (1) informational support, (2) clinical support, and (3) personal support. Key sources of informational and clinical support included pre-optimisation clinics, surgeons, and physiotherapists. Key topics for informational support included pain, pain management, and recovery trajectories. Personal support was provided by family, friends, other TKA patients, employers, and themselves.

 Conclusions: Patient needs and expectations for support are shaped both before and after TKA surgery. Patients with an overall positive TKA experience had improvement in their knee pain, stiffness or functioning post-TKA, had their major expectations and needs for support met during their TKA recovery, and believed that any significant future expectations or needs for ongoing support would be adequately met. In contrast, patients with an overall negative TKA experience had at least one major expectation or need for support not met during their TKA recovery, even in cases where they had good TKA outcomes. Suggested interventions to improve the experience of persons receiving TKA include an expanded patient navigator model, revised pre-surgery educational materials, particularly around pain expectations and management, and comprehensive sharing of other patients’ TKA experience.

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Article
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