Xiaoqi Feng

Is Neighborhood Green Space Associated With a Lower Risk of Type 2 Diabetes? Evidence From 267,072 Australians

OBJECTIVE Lifestyle interventions for type 2 diabetes mellitus (T2DM) are best positioned for success if participants live in supportive neighborhood environments. Deprived neighborhoods increase T2DM risk. Parks and other “green spaces” promote active lifestyles and therefore may reduce T2DM risk. We investigated association between neighborhood green space and the risk of T2DM in a large group of adult Australians. RESEARCH DESIGN AND METHODS Multilevel logit regression was used to fit associations between medically diagnosed T2DM and green space exposure among 267,072 participants in the 45 and Up Study. Green space data were obtained from the Australian Bureau of Statistics, and exposure was calculated using a 1‐km buffer from a participant’s place of residence. Odds ratios (ORs) were controlled for measures of demographic, cultural, health, diet, active lifestyles, socioeconomic status, and neighborhood circumstances. RESULTS The rate of T2DM was 9.1% among participants in neighborhoods with 0–20% green space, but this rate dropped to approximately 8% for participants with over 40% green space within their residential neighborhoods. The risk of T2DM was significantly lower in greener neighborhoods, controlling for demographic and cultural factors, especially among participants residing in neighborhoods with 41–60% green space land use (OR 0.87; 95% CI 0.83–0.92). This association was consistent after controlling for other explanatory variables and did not vary according to neighborhood circumstances. CONCLUSIONS People in greener surroundings have a lower risk of T2DM. Planning, promoting, and maintaining local green spaces is important in multisector initiatives for addressing the T2DM epidemic.

Health and the 2008 economic recession : evidence from the United Kingdom

Introduction The economic recession which began in 2008 has resulted in a substantial increase in unemployment across many countries, including the United Kingdom. Strong association between unemployment and poor health status among individuals is widely recognised. We investigated whether the prevalence of poor health at a population level increased concurrent to the rise in unemployment during the economic recession, and whether the impact on health varied by geographical and socioeconomic circumstances. Method Health, demographic and socioeconomic measures on 1.36 million survey responses aged 16–64 were extracted from the Quarterly Labour Force Survey of the United Kingdom, collected every three months, from January 2006 to December 2010. The likelihood of self-reporting poor health status and specific types of health problems (depression, mental illness, cardiovascular and respiratory) across time were estimated separately using logistic regression. Explanatory variables included economic status (International Labour Organization definition), occupational class, age, gender, country of birth, ethnicity, educational qualifications, couple status, household tenure, number of dependents, and geographical region. Results Unemployment (age-gender adjusted) rose from 4.5% in January 2008 to 7.1% by September 2009. The reporting of poor health status increased from 25.7% in July 2009 to 29.5% by December 2010. Similar increases were found for cardiovascular and respiratory health problems; not depression or mental illness. The prevalence of poor health status among the unemployed decreased from 28.8% in July 2008, to 24.9% by March 2009; but this was followed by an increase in poor health experienced across all regions and by all socioeconomic groups, including those who remained employed, regardless of their occupational class. Interpretation Although our study found no exacerbation of pre-recession health inequalities, the rise in poor health status not only for the unemployed, but also among people who remained employed, regardless of their occupational class, justifies concern voiced among many public health commentators.

Mental health benefits of neighbourhood green space are stronger among physically active adults in middle-to-older age: Evidence from 260,061 Australians

OBJECTIVE While many studies report that green spaces promote mental health, some suggest the psychological benefits of physical activity are amplified if participation occurs within greener environs. We investigated whether this relationship could be observed among adults in middle-to-older age. METHOD Multilevel logit regression was used to investigate association between green space and psychological distress (Kessler scores of 22+) among 260,061 Australians over 45 years old living in New South Wales (2006-2009). Physical activity was measured using the Active Australia survey. Percentage green space was estimated within a 1-kilometre of residence. RESULTS In comparison to residents of the least green areas, those in the greenest neighbourhoods were at a lower risk of psychological distress (Odds Ratio 0.83, 95% CI: 0.76, 0.92) and were less sedentary (0.81: 0.77, 0.87). An interaction was observed between physical activity and green space (p=0.0028). More green space did not appear to benefit mental health among the least active (0.99: 0.85, 1.15), but there was a protective association for the more physically active (0.82: 0.67, 0.99). CONCLUSION For adults in middle-to-older age, green spaces are not only important for promoting physical activity, but the mental health benefits of greener environs appear contingent upon those active lifestyles.

Does access to neighbourhood green space promote a healthy duration of sleep? Novel findings from a cross- sectional study of 259 319 Australians

Objectives Experiments demonstrate that exposure to parks and other ‘green spaces’ promote favourable psychological and physiological outcomes. As a consequence, people who reside in greener neighbourhoods may also have a lower risk of short sleep duration (<6 h). This is potentially important as short sleep duration is a correlate of obesity, chronic disease and mortality, but so far this hypothesis has not been previously investigated. Design Cross-sectional data analysis. Setting New South Wales, Australia. Participants This study investigated whether neighbourhood green space was associated with a healthier duration of sleep (to the nearest hour) among 259 319 Australians who completed the 45 and Up Study baseline questionnaire between 2006 and 2009 inclusive. Primary and secondary outcome measures Multinomial logit regression was used to investigate the influence of an objective measure of green space on categories of sleep duration: 8 h (normal); between 9 and 10 h (mid-long sleep); over 10 h (long sleep); between 6 and 7 h (mid-short sleep); and less than 6 h (short sleep). Models were adjusted for psychological distress, physical activity and a range of demographic and socioeconomic characteristics. Results People living in greener neighbourhoods reported a lower risk of short sleep. For example, compared with participants living in areas with 20% green space land-use, the relative risk ratios for participants with 80%+ green space was 0.86 (95% CI 0.81 to 0.92) for durations between 6 and 7 h, and 0.68 (95% CI 0.57 to 0.80) for less than 6 h sleep. Unexpectedly, the benefit of more green space for achieving 8 h of sleep was not explained by controls for psychological distress, physical activity or other socioeconomic factors. Conclusions Green space planning policies may have wider public health benefits than previously recognised. Further research in the role of green spaces in promoting healthier sleep durations and patterns is warranted.

Exploring pathways linking greenspace to health: Theoretical and methodological guidance

Background In a rapidly urbanizing world, many people have little contact with natural environments, which may affect health and well‐being. Existing reviews generally conclude that residential greenspace is beneficial to health. However, the processes generating these benefits and how they can be best promoted remain unclear. Objectives During an Expert Workshop held in September 2016, the evidence linking greenspace and health was reviewed from a transdisciplinary standpoint, with a particular focus on potential underlying biopsychosocial pathways and how these can be explored and organized to support policy‐relevant population health research. Discussions Potential pathways linking greenspace to health are here presented in three domains, which emphasize three general functions of greenspace: reducing harm (e.g. reducing exposure to air pollution, noise and heat), restoring capacities (e.g. attention restoration and physiological stress recovery) and building capacities (e.g. encouraging physical activity and facilitating social cohesion). Interrelations between among the three domains are also noted. Among several recommendations, future studies should: use greenspace and behavioural measures that are relevant to hypothesized pathways; include assessment of presence, access and use of greenspace; use longitudinal, interventional and (quasi)experimental study designs to assess causation; and include low and middle income countries given their absence in the existing literature. Cultural, climatic, geographic and other contextual factors also need further consideration. Conclusions While the existing evidence affirms beneficial impacts of greenspace on health, much remains to be learned about the specific pathways and functional form of such relationships, and how these may vary by context, population groups and health outcomes. This Report provides guidance for further epidemiological research with the goal of creating new evidence upon which to develop policy recommendations. HighlightsAlthough it appears that greenspace benefits health, the pathways are unclear.We have organized pathways into three domains that emphasize greenspace functions.Pathways likely intertwine and vary by context, populations and health outcomes.We identify diverse challenges in measurement and analysis that require attention.Research guided by our discussion will better efforts to enable greenspace‐related health benefits.

Greener neighborhoods, slimmer people? Evidence from 246 920 Australians

Although there is growing consensus that population-level improvements in cardiovascular health depend upon environments that promote healthy lifestyles, evidence to support large-scale investments in neighborhood greenery to tackle obesity is inconsistent and has not focused on adults in middle-to-old age who experience the greatest burden of chronic health problems. Multilevel linear and multinomial logit regression models were fitted to investigate association between body mass index and an objective measure of green space in a sample of 246 920 Australian adults aged 45 years and older (The 45 and Up Study). Proximity to green space was constructed using catchment areas of 1 km radius around each participant. Women with over 80% proximity to green space had relative risk ratios of 0.90 (95% confidence interval: 0.83, 0.97) for overweight and 0.83 (0.74, 0.94) for obese. No similarly protective association was found for men. These results were consistent after controlling for moderate-to-vigorous physical activity (MVPA) and sitting time, each of which was favorably associated with green space proximity in men and women. Large-scale investments to enhance green spaces may promote MVPA and reduce sedentary behavior in middle-to-older-aged adults, but the impact on obesity may not benefit everyone to the same extent.

Green space is associated with walking and moderate-to-vigorous physical activity (MVPA) in middle-to-older-aged adults: findings from 203 883 Australians in the 45 and Up Study

Background Green space is widely hypothesised to promote physical activity. Few studies, however, examine whether this is the case for walking and moderate-to-vigorous physical activity (MVPA). We investigated to what extent neighbourhood green space was associated with weekly participation and frequency of walking and MVPA in a large cross-sectional survey of Australian adults 45 years and older. Methods Logit and negative binomial regression were used to estimate the degree of association between walking, MVPA and neighbourhood green space in a sample of 203 883 adults from the Australian 45 and Up Study. Walking and MVPA were measured using the Active Australia Survey. Green space was measured as a percentage of the total land-use within 1 km radius of residence. We controlled for a range of individual and neighbourhood characteristics. Results 86.6% of the sample walked and 85.8% participated in MVPA at least once a week. These rates fell steeply with age. Compared with residents of neighbourhoods containing 0–20% green space, those in greener areas were significantly more likely to walk and participate in MVPAs at least once a week (trend for both p<0.001). Among those participating at least once a week, residents of neighbourhoods containing 80%+ green space participated with a greater frequency of walking (incidence rate ratio (IRR) 1.09, 95% CI 1.05 to 1.13) and MVPA (IRR 1.10, 95% CI 1.05 to 1.15). Conclusions Our findings suggest that the amount of green space available to adults in middle-to-older age within their neighbourhood environments could help to promote walking and MVPA.

Geographical Variation in Diabetes Prevalence and Detection in China: Multilevel Spatial Analysis of 98,058 Adults

OBJECTIVE To investigate the geographic variation in diabetes prevalence and detection in China. RESEARCH DESIGN AND METHODS Self-report and biomedical data were collected from 98,058 adults aged ≥18 years (90.5% response) from 162 areas spanning mainland China. Diabetes status was assessed using American Diabetes Association criteria. Among those with diabetes, detection was defined by prior diagnosis. Choropleth maps were used to visually assess geographical variation in each outcome at the provincial level. The odds of each outcome were assessed using multilevel logistic regression, with adjustment for person- and area-level characteristics. RESULTS Geographic visualization at the provincial level indicated widespread variation in diabetes prevalence and detection across China. Regional prevalence adjusted for age, sex, and urban/rural socioeconomic circumstances (SECs) ranged from 8.3% (95% CI 7.2%, 9.7%) in the northeast to 12.7% (11.1%, 14.6%) in the north. A clear negative gradient in diabetes prevalence was observed from 13.1% (12.0%, 14.4%) in the urban high-SEC to 8.7% (7.8%, 9.6%) in rural low-SEC counties/districts. Adjusting for health literacy and other person-level characteristics only partially attenuated these geographic variations. Only one-third of participants living with diabetes had been previously diagnosed, but this also varied substantively by geography. Regional detection adjusted for age, sex, and urban/rural SEC, for example, spanned from 40.4% (34.9%, 46.3%) in the north to 15.6% (11.7%, 20.5%) in the southwest. Compared with detection of 40.8% (37.3%, 44.4%) in urban high-SEC counties, detection was poorest among rural low-SEC counties at just 20.5% (17.7%, 23.7%). Person-level characteristics did not fully account for these geographic variations in diabetes detection. CONCLUSIONS Strategies for addressing diabetes risk and improving detection require geographical targeting.

Suicide by pesticide poisoning remains a priority for suicide prevention in China: analysis of national mortality trends 2006-2013

BACKGROUND Despite recent declines, suicide remains a priority for China. Ease of availability of high-lethality suicide methods, such as pesticides and firearms, contributes to the overall incidence and is an important target for suicide prevention. This study investigates whether changes in the distribution of methods of suicide have contributed to the recent reduction in suicide in China. METHOD Suicide rates (2006-2013) were calculated using the Chinese Disease Surveillance Points system, stratified by gender, age group, and urban-rural residence, to investigate trends in suicide over the study period. Multilevel negative binomial regression models were used to investigate associations between socio-demographic factors and method-specific suicide. RESULTS The most common method of suicide in China for both males and females was pesticide poisoning, followed by hanging. All methods declined over the study period, with the exception of suicide by jumping in males. Suicide rates for pesticide poisoning and for hanging increased exponentially with age in those aged over ≥45 years in both sexes. Pesticide poisoning declined from 55% to 49% of all suicides, while hanging increased from 27% to 31%. LIMITATIONS This was an ecological study of a time series of suicide rates, with risk factor adjustment being limited to population-level point estimates derived from a single census. CONCLUSIONS Suicide by pesticide poisoning and hanging remain the leading methods of suicide in China. Changes to the safe use of pesticides and targeted prevention initiatives to restrict access, along with socio-economic development and urbanisation, are likely contributors to declines in suicide by pesticide poisoning.

Spatiotemporal variation and social determinants of suicide in China, 2006-2012: findings from a nationally representative mortality surveillance system.

BACKGROUND Suicide in China has declined since the 1990s. However, there has been limited investigation of the potential spatiotemporal variation and social determinants of suicide during subsequent periods. METHOD Annual suicide counts from 2006 to 2012 stratified by county, 5-year age group (⩾15 years) and gender were obtained from the Chinese Disease Surveillance Points system. Trends and geographic differentials were examined using multilevel negative binomial regression models to explore spatiotemporal variation in suicide, and the role of key sociodemographic factors associated with suicide. RESULTS The suicide rate (per 100 000) in China decreased from 14.7 to 9.1, 2006-2012. Rates of suicide were higher in males than females and increased substantially with age. Suicide rates were higher in rural areas compared with urban areas; however, urban-rural disparities reduced over time with a faster decline for rural areas. Within both urban and rural areas, higher rates of suicide were evident in areas with lower socio-economic circumstances (SEC) [rate ratio (RR) 1.85, 95% confidence interval (CI) 1.31-2.62]. Suicide rates varied more than twofold (median RR 2.06) across counties, and were highest in central and southwest regions of China. A high proportion of the divorced population, especially for younger females, was associated with lower suicide rates (RR 0.60, 95% CI 0.46-0.79). CONCLUSIONS Geographic variations for suicide should be taken into account in policy making, particularly for older males living in rural areas and urban areas with low SEC. Measures to reduce disparities in socio-economic level and alleviate family relation stress are current priorities.