Vikram Nichani’s research while affiliated with University of Saskatchewan and other places

Evidence suggests that neighbourhood street connectivity is positively associated with physical activity, yet few studies have estimated its associations with sedentary behaviour. We estimated the associations between space syntax derived street integration, a novel measure of street connectivity, and sedentary behaviours among Canadian adults. Data were sourced from a population-based study–Alberta’s Tomorrow Project (n = 14,758). Items from the International Physical Activity Questionnaire captured sedentary behaviour, including sitting and motor vehicle travel time and walking. Street integration was measured within a 1600m radius of participants’ homes. Covariate-adjusted linear regression models estimated the associations between street integration and sedentary behaviour. Street integration was significantly positively associated with daily minutes of sitting on week (b 6.44; 95CI 3.60, 9.29) and weekend (b 4.39; 95CI 1.81, 6.96) days, and for week and weekend days combined (b 5.86; 95CI 3.30, 8.41) and negatively associated with daily minutes of motor vehicle travel (b -3.72; 95CI -3.86, -1.55). These associations remained significant after further adjustment for daily walking participation and duration. More research is needed to understand the pathways by which street integration positively and or negatively affects sedentary behaviour.

Evidence of associations between neighbourhood built characteristics and sedentary behaviours is mixed. The study aim was to investigate the associations between objectively-derived neighbourhood built characteristics and self-reported sedentary behaviours among Canadian men and women. This study sourced survey data from Alberta's Tomorrow Project (2008; n = 14,785), in which sitting and motor vehicle travel times during the last 7 days was measured. Geographic Information System was used to calculate neighbourhood built characteristics within a 400 m buffer of participant's home and a walkability score was estimated. To estimate the associations between neighbourhood characteristics and sedentary behaviours, covariate-adjusted generalized linear regression models were used. Walkability, 3-way intersections, and population count were positively associated with sitting time. Business destinations and greenness were negatively associated with sitting time. Walkability, 3-way, and 4-way intersections were negatively associated with motor vehicle travel time. Sex-specific associations between neighbourhood characteristics and sedentary behaviour were found. Among men, business destinations were negatively associated with sitting time, and 3-way intersections, population count, and walkability were negatively associated with motor vehicle travel time. Among women, Normalized Difference Vegetation Index was negatively associated with sitting time. Interventions to reduce sedentary behaviours may need to target neighbourhoods that have built characteristics which might support these behaviours. More research is needed to disentangle the complex relationships between different neighbourhood built characteristics and specific types of sedentary behaviour.

This study estimated the associations between neighbourhood characteristics and self-reported body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) risk categories among Canadian men and women. Using data from the Alberta's Tomorrow Project (n = 14,550), we estimated 3- and 4-way intersections, business destinations, population count, and normalized difference vegetation index (NDVI) within a 400 m radius of participant's home. Intersections, business destinations, and population count (z-scores) were summed to create a walkability score. Four-way intersections and walkability were negatively associated with overweight and obesity. Walkability was negatively associated with obesity. NDVI was negatively associated with high-risk WHR and population count and walkability positively associated with high-risk WHR. Among men, population count and walkability were negatively associated with obesity, and business destinations and walkability were negatively associated with overweight and obesity. Among women, NDVI was negatively associated with overweight (including obesity), obesity, and high-risk WC. Interventions promoting healthy weight could incorporate strategies that take into consideration local built environment characteristics.

Objectives: Neighbourhood characteristics can impact the health of residents. This study investigated associations between objectively-derived neighbourhood characteristics, including novel space syntax metrics, and self-reported body mass index (BMI) among Canadian men and women. Methods: Our study included survey data collected from a random cross-section of adults residing in Calgary, Alberta, Canada (n=1,718). The survey, conducted in 2007/2008 captured participant’s sociodemographic characteristics, health, and weight status. Participant’s household postal codes were geocoded and 1600m lined-based network buffers from them were generated. Using geographic information systems, we estimated neighbourhood characteristics within each buffer including business destination density , street intersection density, sidewalk length, and population density. We also calculated street integration and space syntax walkability (street integration plus population density) within each buffer. Using covariate-adjusted regression models , we estimated associations between neighbourhood characteristics and BMI (continuous) and BMI categories (healthy weight versus overweight including obese). The gender-stratified analysis was also performed. Results: Business destination density was negatively associated with BMI and the odds of being overweight. Among men, street intersection density and sidewalk length were negatively associated with BMI and street intersection density, business destination density, street integration, and space syntax walkability were negatively associated with the odds of being overweight. Among women, business destination density was negatively associated with BMI. Conclusion: Urban design policies that impact neighbourhoods have the potential to influence weight among adults living in urban Canadian settings. Some characteristics may have a differential association with weight among men and women and should be considered in neighbourhood-focussed urban design and public health interventions.

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 min/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.

Background: Antenatal depression is an important contributor to poor maternal health experienced by some women. This study aimed to determine whether exposure to green space during pregnancy is associated with less depression, and whether this association is moderated by relevant factors, such as age, education, self-identified ethnicity, physical activity, residential rurality, and socioeconomic status. Methods: Health data were sourced from the cohort study “Growing Up in New Zealand” comprised of 6772 participants. Green space was estimated based on the proportion of green space within the Census Area Unit. Adjusted logistic mixed effect models were used to investigate the association between green space and antenatal depression after controlling for confounding variables. Results: Maternal exposure to green space were not associated with lower odds of antenatal depression. Indications of effect modifications due to relevant factors were not observed. Conclusions: This study did not determine an association between access to green space (measured based on the distance to the nearest green space) and antenatal depression. Therefore, a link between green space and antenatal depression was not established. For that reason, ensuring residential areas contain adequate green space may or may not be helpful in preventing antenatal depression and adverse health outcomes associated with this depression. More studies focusing on pregnant women in a range of social contexts, and considering both exposure and access to green space, are warranted to determine the relationships between green space and antenatal depression.

Objectives: To determine whether maternal exposure to green space during pregnancy is associated with birth weight and gestational age, and whether these associations are modified by demographic and residential factors. Methods: Data describing 5091 mother-newborn pairs with residential address during pregnancy linked to data describing their green space exposure. Independent associations determined using linear mixed effects models. Results: Maternal exposure to green space during pregnancy was not associated with birth weight and gestational age for the entire cohort. For pregnant women who have not acquired secondary school education, increased exposure to green space was associated with increased gestational age. Conclusion: The provision of green space might prove to be beneficial in terms of increasing gestational age for pregnant women who have not acquired secondary school education qualifications.

Background: Exposure to green space has been associated with increased physical activity. However, it is not clear whether this association is because active people preferentially live in greener areas. Relationships between exposure to green space and physical activity during pregnancy are not well defined. Our objective was to determine whether exposure to green space was associated with physical activity in pregnant women. Methods: The current study was completed within the Growing Up in New Zealand cohort study of 6772 pregnant women. The proportion of green space in each census area unit was determined and geocoded to residential address. The association between exposure to green space and physical activity was determined using logistic regression analyses after controlling for confounding variables. Results: Exposure to green space was not associated with participation in physical activity during first trimester and the remainder of pregnancy once preference for living in greener neighborhoods was taken into account. Conclusions: The lack of association between green space and physical activity found in this study does not necessarily mean that living in green space will not translate into better pregnancy health. Preference for living in greener neighborhoods should be considered when investigating relationships between green space and physical activity.