Neighbourhood walkability and dietary attributes: effect modification by area-level socio-economic status.

OBJECTIVE: Higher neighbourhood walkability would be expected to contribute to better health, but the relevant evidence is inconsistent. This may be because residents' dietary attributes, which vary with socio-economic status (SES) and influence their health, can be related to walkability. We examined associations of walkability with dietary attributes and potential effect modification by area-level SES. DESIGN: The exposure variable of this cross-sectional study was neighbourhood walkability, calculated using residential density, intersection density and destination density within 1-km street-network buffer around each participant's residence. The outcome variables were dietary patterns (Western, prudent and mixed) and total dietary energy intake, derived from a FFQ. Main and interaction effects with area-level SES were estimated using two-level linear regression models. SETTING: Participants were from all states and territories in Australia. PARTICIPANTS: The analytical sample included 3590 participants (54 % women, age range 34 to 86). RESULTS: Walkability was not associated with dietary attributes in the whole sample. However, we found interaction effects of walkability and area-level SES on Western diet scores (P < 0·001) and total energy intake (P = 0·012). In low SES areas, higher walkability was associated with higher Western dietary patterns (P = 0·062) and higher total energy intake (P = 0·066). In high SES areas, higher walkability was associated with lower Western diet scores (P = 0·021) and lower total energy intake (P = 0·058). CONCLUSIONS: Higher walkability may not be necessarily conducive to better health in socio-economically disadvantaged areas. Public health initiatives to enhance neighbourhood walkability need to consider food environments and socio-economic contexts.

Associations of Vigorous Gardening With Cardiometabolic Risk Markers for Middle-Aged and Older Adults.

This study investigates the associations of vigorous-intensity gardening time with cardiometabolic health risk markers. This cross-sectional study (AusDiab) analyzed 2011-2012 data of 3,664 adults (55% women, mean [range], age = 59.3 [34-94] years) in Australia. Multiple linear regression models examined associations of time spent participating in vigorous gardening (0, <150 min/week, ≥150 min/week) with a clustered cardiometabolic risk (CMR) score and its components, for the whole sample and stratified by age and gender. Of participants, 61% did no vigorous gardening, 23% reported <150 min/week, and 16% reported ≥150 min/week. In the whole sample, spending ≥150 min/week in vigorous gardening was associated with lower CMR (lower CMR score, waist circumference, diastolic blood pressure, and triglycerides) compared with no vigorous gardening. Stratified analyses suggested that these associations were almost exclusively observed for older adults and women. These findings suggest the public health potential of vigorous-intensity gardening in reducing CMR.

Urban Densification and Physical Activity Change: A 12-Year Longitudinal Study of Australian Adults.

Urbanization, a major force driving changes in neighborhood environments, may affect residents' health by influencing their daily activity levels. We examined associations of population density changes in urban areas with adults' physical activity changes over 12 years using data from the Australian Diabetes, Obesity and Lifestyle Study (1999-2012). The analytical sample contained 2,354 participants who remained at the same residential address throughout the study period in metropolitan cities and regional cities (42 study areas). Census-based population density measures were calculated for 1-km-radius buffers around their homes. Population density change was estimated using linear growth models. Two-level linear regression models were used to assess associations between changes in population density and changes in self-reported walking and physical activity durations. The average change in population density was 0.8% per year (range, -4.1 to 7.8) relative to baseline density. After adjustment for confounders, each 1% annual increase in population density was associated with 8.5-minutes/week (95% confidence interval: 0.6, 16.4) and 19.0-minutes/week (95% confidence interval: 3.7, 34.4) increases in walking and physical activity, respectively, over the 12-year study period. Increasing population density through urban planning policies of accommodating population growth within the existing urban boundary, rather than expanding city boundaries, could assist in promoting physical activity at the population level.

Neighborhood walkability and 12-year changes in cardio-metabolic risk: the mediating role of physical activity.

BACKGROUND: Living in walkable neighborhoods may provide long-term cardio-metabolic health benefits to residents. Little empirical research has examined the behavioral mechanisms in this relationship. In this longitudinal study, we examined the potential mediating role of physical activity (baseline and 12-year change) in the relationships of neighborhood walkability with 12-year changes in cardio-metabolic risk markers. METHODS: The Australian Diabetes, Obesity and Lifestyle study collected data from adults, initially aged 25+ years, in 1999-2000, 2004-05, and 2011-12. We used 12-year follow-up data from 2023 participants who did not change their address during the study period. Outcomes were 12-year changes in waist circumference, weight, systolic and diastolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein cholesterol, and triglycerides. A walkability index was calculated, using dwelling density, intersection density, and destination density, within 1 km street-network buffers around participants' homes. Spatial data for calculating these measures were sourced around the second follow-up period. Physical activity was assessed by self-reported time spent in moderate-to-vigorous physical activity (including walking). Multilevel models, adjusting for potential confounders, were used to examine the total and indirect relationships. The joint-significance test was used to assess mediation. RESULTS: There was evidence for relationships of higher walkability with smaller increases in weight (P = 0.020), systolic blood pressure (P < 0.001), and high-density lipoprotein cholesterol (P = 0.002); and, for relationships of higher walkability with higher baseline physical activity (P = 0.020), which, in turn, related to smaller increases in waist circumference (P = 0.006), weight (P = 0.020), and a greater increase in high-density lipoprotein cholesterol (P = 0.005). There was no evidence for a relationship of a higher walkability with a change in physical activity during the study period (P = 0.590). CONCLUSIONS: Our mediation analysis has shown that the protective effects of walkable neighborhoods against obesity risk may be in part attributable to higher baseline physical activity levels. However, there was no evidence of mediation by increases in physical activity during the study period. Further research is needed to understand other behavioral pathways between walkability and cardio-metabolic health, and to investigate any effects of changes in walkability.

Area-level socioeconomic inequalities in overweight and obesity: Systematic review on moderation by built-environment attributes.

Residents of lower socioeconomic status (SES) areas are at a higher risk of overweight/obesity than those from higher SES areas. Built environment attributes may mitigate such inequalities. This systematic review synthesised findings of studies examining built environment attributes as potential moderators of the associations between area-level SES and overweight/obesity in adults. From five databases, nine eligible studies were identified. The SES-overweight/obesity relationship was stronger in inner areas and suburbs of large cities, while it was weaker in more rural areas. Two studies examined walkability and reported contrasting findings: no moderation in one and marginally significant moderation (less inequality in higher walkability areas) in the other. No evidence of moderation was found for street connectivity, population density, the food environment, access to physical activity facilities and several perceived environmental attributes. Further research is needed on other built environment attributes (e.g., access to, quantity and quality of green spaces, active transport features), and ideally using prospective study designs and objective makers of adiposity.

Area-level associations of travel behaviour metrics with waist circumference: findings from linkage of travel and health surveys.

Individual-level analyses have consistently shown associations of travel behaviours with obesity-related measures. However, transport planning policies often target areas rather than individuals. To better inform transport-related policies and initiatives for obesity prevention, area-level relationships need to be investigated. This study linked data from two travel surveys with data from the Australian National Health Survey at the level of Population Health Areas (PHAs) and examined to what extent area-level travel behaviours metrics (prevalence of active travel, mixed travel and sedentary travel, diversity of travel modes) were associated with the rate of high waist circumference. Data from 51,987 travel survey participants were aggregated into 327 PHAs. Bayesian conditional autoregressive models were used to account for spatial autocorrelation. It was found that statistically replacing participants who relied on cars for travel (without walking/cycling) with those engaging in 30+ min/d of walking/cycling (without car use) was associated with a lower rate of high waist circumference. Areas with greater diversity of travel modes (mix of walking/cycling, car use, public transport use) also had lower prevalence of high waist circumference. This data-linkage study suggests that area-level transport planning strategies addressing car dependency, shifting car use to walking/cycling over 30 min/d, may help to reduce obesity.

Neighborhood socioeconomic status and cardiometabolic risk: mediating roles of domain-specific physical activities and sedentary behaviors.

PURPOSE: We examined the potential mediating roles of domain-specific physical activities and sedentary behaviors in the relationship between area-level socioeconomic status (SES) and cardiometabolic risk. METHODS: Data were from the 2011/2012 Australian Diabetes, Obesity and Lifestyle study (n = 3431). The outcome was a clustered cardiometabolic risk (CCR) score, and the exposure was suburb-level SES. Potential mediators were domain-specific physical activities and sedentary behaviors. Multilevel linear regression models examined associations between SES and potential mediators (α) and between mediators and CCR (ß). Mediation was assessed using the joint-significance test. RESULTS: Higher SES was associated with a lower CCR score. Lower SES was associated with less frequent walking for transport, lower vigorous-intensity recreational physical activity, and higher TV time, which were associated with higher CCR scores. However, higher SES was associated with longer transport-related sitting time (all modes and in cars), which were associated with higher CCR scores. CONCLUSIONS: The SES-cardiometabolic risk relationship may be partially explained by walking for transport, vigorous-intensity recreational physical activity, and TV viewing. These findings, which require corroboration from prospective evidence and clarification of the roles of transport-related sitting and occupational physical activity, can inform initiatives addressing socioeconomic inequalities in cardiometabolic health.

Built Environments and Cardiovascular Health: REVIEW AND IMPLICATIONS.

PURPOSE: This review presents a general overview of the state of evidence on the relationships between neighborhood built environments and cardiovascular health outcomes among adults. We also summarize relevant literature on the associations of built environments with active living behaviors (physical activity [PA] and sedentary behavior), as they are considered as key behavioral pathways. REVIEW METHODS: We identified recently published systematic reviews assessing associations of built environment attributes with cardiovascular health outcomes or active living behaviors. We summarized findings of the key systematic reviews and presented findings of pertinent empirical studies, where appropriate. SUMMARY: Increasing evidence suggests that living in a place supportive of engaging in PA for transportation (eg, walkability features) and recreation (eg, parks) can be protective against cardiovascular disease (CVD) risk. Places conducive to higher levels of sedentary travel (ie, prolonged sitting in cars) may have adverse effects on cardiovascular health. The built environment of where people live can affect how active they are and subsequently their cardiovascular health. Clinical professionals are encouraged to consider the built environment features of where their patients live in counseling, as this may assist them to understand potential opportunities or barriers to active living and to propose a suitable CVD prevention strategy.

Associations of park features with park use and park-based physical activity in an urban environment in Asia: A cross-sectional study.

Park use is associated with health, yet our understanding of park features related to their use is limited. Singapore's parks were audited for 30 micro-features, then geospatial analysis characterized micro-features scores for parks nearest to participants' homes. Adults (3,435) reported their park use and park-based physical activity. Using linear regression models, we found living near a park with higher micro-features scores was associated with more time in parks and park-based physical activity. Specific micro-features were associated with more park time (wildlife areas, water features, forested areas, unpaved trails (2-2.6 h/month, p < 0.05)) and with physical activity in parks (water features, forested areas, large playground, open green spaces (1.8-2.2 h/month, p < 0.05)). These findings could inform parks planning to support population-health.

Urban Densification and 12-Year Changes in Cardiovascular Risk Markers.

Background Population densities of many cities are increasing rapidly, with the potential for impacts on cardiovascular health. This longitudinal study examined the potential impact of population-density increases in urban areas (urban densification) on cardiovascular risk markers among Australian adults. Methods and Results Data were from the Australian Diabetes, Obesity and Lifestyle Study, in which adult participants' cardiovascular risk markers were collected in 3 waves (in 1999-2000, 2004-2005, and 2011-2012). We included 2354 participants with a mean age of 51 years at baseline who did not change their residence during the study period. Outcomes were 12-year changes in waist circumference, weight, systolic and diastolic blood pressure, fasting and 2-hour postload plasma glucose, high-density lipoprotein cholesterol, and triglycerides. The exposure was neighborhood population densification, defined as 12-year change in population density within a 1-km radius buffer around the participant's home. Multilevel linear growth models, adjusting for potential confounders, were used to examine the relationships. Each 1% annual increase in population density was related with smaller increases in waist circumference (b=-0.043 cm/y; 95% CI, -0.065 to -0.021 [P<0.001]), weight (b=-0.019 kg/y; 95% CI, -0.039 to 0.001 [P=0.07]), and high-density lipoprotein cholesterol (b=-0.035 mg/dL per year; 95% CI, -0.067 to -0.002 [P=0.04]), and greater increases in diastolic blood pressure (b=0.032 mm Hg/y; 95% CI, -0.004 to 0.069 [P=0.08]). Conclusions Our findings suggest that, at least in the context of Australia, urban densification may be protective against obesity risk but may have adverse effects on blood lipids and blood pressure. Further research is needed to understand the mechanisms through which urban densification influences cardiovascular health.