Association between Residential Greenness and Allostatic Load: A Cohort Study.

The association between residential greenness and allostatic load (AL), a marker of composite physiological burden and predictor of chronic disease, remains understudied. This study comprised 212,600 UK Biobank participants recruited over 2007 and 2010 at the baseline. Residential greenness was modeled as the normalized difference vegetation index (NDVI) from high spatial resolution (0.50 m) color infrared imagery and measured within a 0.5 km radial catchment. AL was measured as a composite index from 13 biomarkers comprising three physiological systems (metabolic, cardiovascular, and inflammatory systems) and two organ systems (liver and kidney). Multilevel mixed-effects generalized linear models with a random intercept for UK Biobank assessment centers were employed to examine the association between residential greenness and AL. Each interquartile range (IQR = 0.24) increment in NDVI greenness was associated with lower AL (beta (ß) = -0.28, 95% confidence interval (CI) = -0.55, -0.01). Consistently, relative to the lowest NDVI greenness quintile, participants in the highest quintile had lower AL (ß = -0.64, 95% CI = -1.02, -0.26). The proportion of the association between greenness and AL mediated by the physical activity was 3.2%. In conclusion, residential greenness was protectively associated with AL, a composite marker of wear and tear and general health.

Associations between Short-Term Exposure to Ambient Air Pollution and Influenza: An Individual-Level Case-Crossover Study in Guangzhou, China.

BACKGROUND: Influenza imposes a heavy burden on public health. Little is known, however, of the associations between detailed measures of exposure to ambient air pollution and influenza at an individual level. OBJECTIVE: We examined individual-level associations between six criteria air pollutants and influenza using case-crossover design. METHODS: In this individual-level time-stratified case-crossover study, we linked influenza cases collected by the Guangzhou Center for Disease Control and Prevention from 1 January 2013 to 31 December 2019 with individual residence-level exposure to particulate matter (PM2.5 and PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). The exposures were estimated for the day of onset of influenza symptoms (lag 0), 1-7 d before the onset (lags 1-7), as well as an 8-d moving average (lag07), using a random forest model and linked to study participants' home addresses. Conditional logistic regression was developed to investigate the associations between short-term exposure to air pollution and influenza, adjusting for mean temperature, relative humidity, public holidays, population mobility, and community influenza susceptibility. RESULTS: N=108,479 eligible cases were identified in our study. Every 10-µg/m3 increase in exposure to PM2.5, PM10, NO2, and CO and every 5-µg/m3 increase in SO2 over 8-d moving average (lag07) was associated with higher risk of influenza with a relative risk (RR) of 1.028 (95% CI: 1.018, 1.038), 1.041 (95% CI: 1.032, 1.049), 1.169 (95% CI: 1.151, 1.188), 1.004 (95% CI: 1.003, 1.006), and 1.134 (95% CI: 1.107, 1.163), respectively. There was a negative association between O3 and influenza with a RR of 0.878 (95% CI: 0.866, 0.890). CONCLUSIONS: Our findings suggest that short-term exposure to air pollution, except for O3, is associated with greater risk for influenza. Further studies are necessary to decipher underlying mechanisms and design preventive interventions and policies. https://doi.org/10.1289/EHP12145.

Associations of Urban Built Environment with Cardiovascular Risks and Mortality: a Systematic Review.

With rapid urbanization, built environment has emerged as a set of modifiable factors of cardiovascular disease (CVD) risks. We conducted a systematic review to synthesize evidence on the associations of attributes of urban built environment (e.g. residential density, land use mix, greenness and walkability) with cardiovascular risk factors (e.g. hypertension and arterial stiffness) and major CVD events including mortality. A total of 63 studies, including 31 of cross-sectional design and 32 of longitudinal design conducted across 21 geographical locations and published between 2012 and 2023 were extracted for review. Overall, we report moderately consistent evidence of protective associations of greenness with cardiovascular risks and major CVD events (cross-sectional studies: 12 of 15 on hypertension/blood pressure (BP) and 2 of 3 on arterial stiffness; and longitudinal studies: 6 of 8 on hypertension/BP, 7 of 8 on CVD mortality, 3 of 3 on ischemic heart disease mortality and 5 of 8 studies on stroke hospitalization or mortality reporting significant inverse associations). Consistently, walkability was associated with lower risks of hypertension, arterial stiffness and major CVD events (cross-sectional studies: 11 of 12 on hypertension/BP and 1 of 1 on arterial stiffness; and longitudinal studies: 3 of 6 on hypertension/BP and 1 of 2 studies on CVD events being protective). Sixty-seven percent of the studies were rated as "probably high" risk of confounding bias because of inability to adjust for underlying comorbidities/family history of diseases in their statistical models. Forty-six percent and 14% of the studies were rated as "probably high" risk of bias for exposure and outcome measurements, respectively. Future studies with robust design will further help elucidate the linkages between urban built environment and cardiovascular health, thereby informing planning policies for creating healthy cities.

Association of climatic variables with risk of transmission of influenza in Guangzhou, China, 2005-2021.

BACKGROUND: Climatic variables constitute important extrinsic determinants of transmission and seasonality of influenza. Yet quantitative evidence of independent associations of viral transmissibility with climatic factors has thus far been scarce and little is known about the potential effects of interactions between climatic factors on transmission. OBJECTIVE: This study aimed to examine the associations of key climatic factors with risk of influenza transmission in subtropical Guangzhou. METHODS: Influenza epidemics were identified over a 17-year period using the moving epidemic method (MEM) from a dataset of N = 295,981 clinically- and laboratory-confirmed cases of influenza in Guangzhou. Data on eight key climatic variables were collected from China Meteorological Data Service Centre. Generalized additive model combined with the distributed lag non-linear model (DLNM) were developed to estimate the exposure-lag-response curve showing the trajectory of instantaneous reproduction number (Rt) across the distribution of each climatic variable after adjusting for depletion of susceptible, inter-epidemic effect and school holidays. The potential interaction effects of temperature, humidity and rainfall on influenza transmission were also examined. RESULTS: Over the study period (2005-21), 21 distinct influenza epidemics with varying peak timings and durations were identified. Increasing air temperature, sunshine, absolute and relative humidity were significantly associated with lower Rt, while the associations were opposite in the case of ambient pressure, wind speed and rainfall. Rainfall, relative humidity, and ambient temperature were the top three climatic contributors to variance in transmissibility. Interaction models found that the detrimental association between high relative humidity and transmissibility was more pronounced at high temperature and rainfall. CONCLUSION: Our findings are likely to help understand the complex role of climatic factors in influenza transmission, guiding informed climate-related mitigation and adaptation policies to reduce transmission in high density subtropical cities.

The associations of socioeconomic status with incident dementia and Alzheimer's disease are modified by leucocyte telomere length: a population-based cohort study.

Socio-economic status (SES) and biological aging are risk factors for dementia, including Alzheimer's disease, however, it is less clear if the associations with SES vary sufficiently across different biological age strata. We used data from 331,066 UK Biobank participants aged 38-73 with mean follow-up of 12 years to examine if associations between SES (assessed by educational attainment, employment status and household income) and dementia and Alzheimer's disease are modified by biological age (assessed by leucocyte telomere length: LTL). Diagnosis of events was ascertained through hospital admissions data. Cox regressions were used to estimate hazard ratios [HRs]. A consistent dose-response relationship was found, with participants in low SES and shorter LTL strata (double-exposed group) reporting 3.28 (95% confidence interval [CI] 2.57-4.20) and 3.44 (95% CI 2.35-5.04) times higher risks of incident dementia and Alzheimer's disease respectively, compared to those of high SES and longer LTL (least-exposed group). Of interest is a synergistic interaction between SES and LTL to increase risk of dementia (RERI 0.57, 95% CI 0.07-1.06) and Alzheimer's disease (RERI 0.79, 95% CI 0.02-1.56). Our findings that SES and biological age (LTL) are synergistic risk factors of dementia and Alzheimer's disease may suggest the need to target interventions among vulnerable sub-groups.

Neighbourhood residential density, urbanicity and incident dementia and Alzheimer's disease: A 12-year prospective cohort study from the UK Biobank.

INTRODUCTION: An increasing proportion of global population is exposed to urban densification in an aging society. However, little is known of the role of residential density and urbanicity on the risk of developing dementia including Alzheimer's disease. We examined long-term associations between residential density and urbanicity and risks of incident dementia and Alzheimer's disease. METHODS: This prospective cohort study included participants from the UK Biobank who lived at the same residential address, had no self-reported neurological conditions and without dementia at baseline. Residential density was measured as the number of dwelling units within 1-km street neighbourhood of participant's home address. A composite index of urbanicity was developed from neighbourhood-level z-standardized densities of housing, retail, public transport and street centrality. Hazard ratios were derived from Cox proportional hazard models adjusted for known risk factors. RESULTS: The analytic sample included 239,629 participants aged 38-72 years. During a median follow-up of 12.3 years (interquartile range 11.5-13.0 years), 2,176 participants developed dementia and 1,004 Alzheimer's disease. After adjustments for potential risk factors, each 1,000 units/Km2 increment in residential density was associated with higher risks of dementia (hazard ratio [HR]=1.10, 95% confidence interval [CI]: 1.06-1.15) and Alzheimer's disease (HR=1.10, 95% CI: 1.04-1.16). Consistently, categorical models showed that living in neighbourhoods of higher residential density and urbanicity were associated with higher risks of dementia (HR = 1.30, 95% CI: 1.12-1.51 for the highest density quintile compared to the lowest and HR = 1.21, 95% CI: 1.05-1.39 for the highest urbanicity quintile relative to the lowest). The associations were more pronounced in female, age >65 years, and among participants of the low income and those being frail and having shorter leucocyte telomere length (LTL). CONCLUSIONS: Higher residential density and urbanicity was found to be positively associated with elevated risks of dementia and Alzheimer's disease. Optimizing neighbourhood residential density maybe one of the upstream considerations for mitigating against neurodegenerative diseases.

The association between workplace built environment and metabolic health: A systematic review and meta-analysis.

BACKGROUND: Metabolic health is one of the key determinants of healthy living. Specifically, maintaining healthy weight, regulation of blood pressure, lipids and glucose over the life course have been reported to be protective on chronic diseases and premature mortality. With the global workforce spending, on average, one-third of the weekly time budget in the workplace, the role of workplace environment in enhancing metabolic health becomes important. However, there has thus far been no review synthesizing evidence on the links between workplace built environment and metabolic health. METHODS: A systematic review and meta-analysis was conducted synthesizing evidence on the associations of built environment attributes measured within the workplace neighbourhood and metabolic health. A total of 16 studies that fulfilled the inclusion/exclusion criteria were identified via systematic search of English language peer-refereed publications up to July 2021, in six databases. A systematic coding system was developed, indicating significant findings in expected/unexpected directions including null findings, and the quality of the pooled study was assessed. The Weighted-Z test method that accounts for the study quality was used to examine the strength of evidence. RESULTS: A quarter of the pooled studies were categorized to be of high quality. Among the workplace built environment attributes of access to/density of recreational facilities, street pattern, access to/density of destinations and services, and land use mix, very strong evidence was found for the association between access to/density of destinations and services and metabolic health (p < 0.001); specifically, access to full service establishments such as supermarkets, grocery stores and restaurants (p = 0.001). A relatively weak association between proximity to workplace and metabolic health (p = 0.019) was also reported. DISCUSSION: Given the lack of high quality studies, overall confidence in the currently available evidence is 'low'. Well-designed longitudinal studies with rigorous measurements for exposures and outcome variables are necessary.

Community-level ambient fine particulate matter and seasonal influenza among children in Guangzhou, China: A Bayesian spatiotemporal analysis.

BACKGROUND: Influenza is a major preventable infectious respiratory disease. However, there is little detailed long-term evidence of its associations with PM2.5 among children. We examined the community-level associations between exposure to ambient PM2.5 and incident influenza in Guangzhou, China. METHODS: We used data from the city-wide influenza surveillance system collected by Guangzhou Centre for Disease Control and Prevention (GZCDC) over the period 2013 and 2019. Incident influenza was defined as daily new influenza (both clinically diagnosed and laboratory confirmed) cases as per standard diagnostic criteria. A 200-meter city-wide grid of daily ambient PM2.5 exposure was generated using a random forest model. We developed spatiotemporal Bayesian hierarchical models to examine the community-level associations between PM2.5 and the influenza adjusting for meteorological and socioeconomic variables and accounting for spatial autocorrelation. We also calculated community-wide influenza cases attributable to PM2.5 levels exceeding the China Grade 1 and World Health Organization (WHO) regulatory thresholds. RESULTS: Our study comprised N = 191,846 children from Guangzhou aged ≤19 years and diagnosed with influenza between January 1, 2013 and December 31, 2019. Each 10 µg/m3 increment in community-level PM2.5 measured on the day of case confirmation (lag 0) and over a 6-day moving average (lag 0-5 days) was associated with higher risks of influenza (RR = 1.05, 95% CI: 1.05-1.06 for lag 0 and RR = 1.15, 95% CI: 1.14-1.16 for lag 05). We estimated that 8.10% (95%CI: 7.23%-8.57%) and 20.11% (95%CI: 17.64%-21.48%) influenza cases respectively were attributable to daily PM2.5 exposure exceeding the China Grade I (35 µg/m3) and the WHO limits (25 µg/m3). The risks associated with PM2.5 exposures were more pronounced among children of the age-group 10-14 compared to other age groups. CONCLUSIONS: More targeted non-pharmaceutical interventions aimed at reducing PM2.5 exposures at home, school and during commutes among children may constitute additional influenza prevention and control polices.

Associations of residential walkability and greenness with arterial stiffness in the UK Biobank.

BACKGROUND: Arterial stiffness is a key non-invasive marker of early vascular ageing, however, little is known of its associations with urban built environment. We examined the associations of objectively-measured residential walkability and greenness with arterial stiffness in a large UK-wide population cohort. METHODS: We employed data from the baseline UK Biobank cohort comprising adult participants recruited over the period of 2006 to 2010. Residential walkability index, defined as a function of density (residential, retail and public transit), street-level design, and destination accessibility was measured using a 1-Km dwelling catchment, while greenness was modelled as the mean Normalized Difference Vegetation Index (NDVI) of 0.5-metre resolution assessed within a 0.5-Km catchment. Arterial stiffness index (ASI) was measured non-invasively from the pulse waveform. Linear regression models were developed to examine associations of walkability and greenness with arterial stiffness. Restricted cubic spline (RCS) models were developed to examine dose-response relationships. We also examined effect modifications by sex and age, as well as the interaction effect of greenness and walkability. RESULTS: This cross-sectional study used a target sample of 169,704 UK Biobank participants aged ≥ 39 years. After full adjustments, in reference to the lowest walkability exposure quartile, those in the highest were associated with lower ASI (ß = -0.083 m/s, 95% CI: -0.14 to -0.03, p = 0.005). Participants in the third and fourth NDVI greenness exposure quartiles were also associated with lower ASI (ß = -0.074 m/s, -0.14 to -0.01, p < 0.020 for the third and ß = -0.293 m/s, -0.36 to -0.23, p < 0.001 for the fourth quartiles in reference to the first). The inverse association between NDVI greenness and ASI was more pronounced among women (p < 0.001), older adults (p = 0.011) and among participants in the highest walkability quartile (p < 0.001). CONCLUSION: Designing more walkable and greener residential environments can be a preventive intervention aimed at lowering the population distribution of vascular ageing and associated cardiovascular risks.

Liveable residential space, residential density, and hypertension in Hong Kong: A population-based cohort study.

BACKGROUND: Hypertension is a leading preventable risk factor of chronic disease and all-cause mortality. Housing is a fundamental social determinant of health. Yet, little is known about the impacts of liveable residential space and density on hypertension. METHODS AND FINDINGS: This retrospective observational study (median follow-up of 2.2 years) leveraged the FAMILY Cohort, a large territory-wide cohort in Hong Kong, Special Administrative Region, People's Republic of China to quantify associations of objectively measured liveable space and residential density with blood pressure outcomes among adults aged ≥16 years. Blood pressure outcomes comprised diastolic blood pressure (DBP), systolic blood pressure (SBP), mean arterial pressure (MAP), and hypertension. Liveable space was measured as residential floor area, and density was assessed using the number of residential units per building block and neighborhood residential unit density within predefined catchments. Multivariable regression models examined associations of liveable floor area and residential density with prevalent and incident hypertension. We investigated effect modifications by age, sex, income, employment status, and housing type. Propensity score matching was further employed to match a subset of participants who moved to smaller residences at follow-up with equivalent controls who did not move, and generalized linear models examined the impact of moving to smaller residences upon blood pressure outcomes. Our fully adjusted models of prevalent hypertension outcomes comprised 30,439 participants at baseline, while 13,895 participants were available for incident models at follow-up. We found that each interquartile range (IQR) increment in liveable floor area was associated with lower DBP (beta [ß] = -0.269 mm Hg, 95% confidence interval [CI]: -0.419 to -0.118, p < 0.001), SBP (ß = -0.317 mm Hg, -0.551 to -0.084, p = 0.008), MAP (ß = -0.285 mm Hg, -0.451 to -0.119 with p < 0.001), and prevalent hypertension (odds ratio [OR] = 0.955, 0.918 to 0.993, p = 0.022) at baseline. Each IQR increment in residential units per building block was associated with higher DBP (ß = 0.477 mm Hg, 0.212 to 0.742, p = <0.001), SBP (ß = 0.750 mm Hg, 0.322 to 1.177, p = <0.001), MAP (ß = 0.568 mm Hg, 0.269 to 0.866, p < 0.001), and prevalent hypertension (OR = 1.091, 1.024 to 1.162, p = 0.007). Each IQR increase in neighborhood residential density within 0.5-mi street catchment was associated with lower DBP (ß = -0.289 mm Hg, -0.441 to -0.137, p = <0.001), SBP (ß = -0.411 mm Hg, -0.655 to -0.168, p < 0.001), MAP (ß = -0.330 mm Hg, -0.501 to -0.159, p = <0.001), and lower prevalent hypertension (OR = 0.933, 0.899 to 0.969, p < 0.001). In the longitudinal analyses, each IQR increment in liveable floor area was associated with lower DBP (ß = -0.237 mm Hg, -0.431 to -0.043, p = 0.016), MAP (ß = -0.244 mm Hg, -0.444 to -0.043, p = 0.017), and incident hypertension (adjusted OR = 0.909, 0.836 to 0.988, p = 0.025). The inverse associations between larger liveable area and blood pressure outcomes were more pronounced among women and those residing in public housing. In the propensity-matched analysis, participants moving to residences of lower liveable floor area were associated with higher odds of incident hypertension in reference to those who did not move (OR = 1.623, 1.173 to 2.199, p = 0.002). The major limitations of the study are unmeasured residual confounding and loss to follow-up. CONCLUSIONS: We disentangled the association of micro-, meso-, and macrolevel residential densities with hypertension and found that higher liveable floor area and neighborhood scale residential density were associated with lower odds of hypertension. These findings suggest adequate housing in the form of provisioning of sufficient liveable space and optimizing residential density at the building block, and neighborhood levels should be investigated as a potential population-wide preventive strategy for lowering hypertension and associated chronic diseases.

Characteristics of the Residential Environment and Their Association With Depression in Hong Kong.

Importance: With rapid urbanization, understanding the role of residential environments in the development of depression has gained importance. However, the potential associations of residential space and density with depression have been understudied. Objective: To investigate longitudinal associations of residential livable space and density with depression. Design, Setting, and Participants: This longitudinal cohort study used data from 2 waves of the FAMILY Cohort, a population-based cohort in the Hong Kong Special Administrative Region, China, recruited between February 28, 2009, and March 28, 2011, at baseline and followed up between August 3, 2011, and June 19, 2013, at wave 2. Data were analyzed from September 1, 2020, through August 10, 2021. A total of 16 968 participants aged 16 years or older underwent assessment using the Patient Health Questionnaire-9 (PHQ-9) and had complete data across all variables. Exposures: Residential density was objectively assessed at 3 scales (within apartment, building block, and at neighborhood level) at baseline and follow-up. Main Outcomes and Measures: Depressive symptoms were defined in terms of a PHQ-9 threshold greater than or equal to 5 and probable major depression with a cutoff value greater than or equal to 10. A continuous PHQ-9 score was used as a secondary outcome. Multilevel logistic regression models were used to examine associations of the residential density with probable major depression and depressive symptoms adjusted for time-varying sociodemographic and lifestyle factors, comorbidities, and other environment variables. Results: Of the 16 968 participants with complete data, the mean (SD) age was 45.5 (16.7) years, and 9328 participants (55.0%) were women at baseline. The mean follow-up was 2.2 years (range, 1.3-3.6 years). At the household level, after full adjustments, each IQR increment in residential livable area was associated with lower odds of probable major depression (adjusted odds ratio [aOR], 0.84; 95% CI, 0.71-0.98; P = .03) and depressive symptoms (aOR, 0.93; 95% CI, 0.86-1.00; P = .04). At the building-block level, each IQR increment in block density was associated with higher odds of depressive symptoms (aOR, 1.11; 95% CI, 1.01-1.22; P = .03), but only in single-housing environment models. The results remained consistent in models with continuous PHQ-9 evaluation. Conclusions and Relevance: This study's findings suggest that residential livable space and block density may play a role in the development of depression. Integrated mental health and housing policies promoting mental capital in cities, such as health-optimized density at the household and building-block levels, might serve as a population approach to reduce the burden of depression.

Exposure to light at night (LAN) and risk of breast cancer: A systematic review and meta-analysis.

BACKGROUND: With the unprecedented urbanization light pollution has emerged as a ubiquitous problem, and there has been accumulating evidence on the links between exposure to light at night (LAN) and breast cancer risk. We conducted a systematic review and meta-analysis of published studies on the associations between LAN exposure and breast cancer risk. METHODS: We included all observational human studies wherein the exposure variable was LAN measured in indoor and outdoor environments, and the outcome was breast cancer. We employed summary relative risks (SRR) for breast cancer by comparing highest versus lowest categories of LAN exposure within a random-effects model. The National Toxicology Program's (NTP) Office of Health Assessment and Translation (OHAT) risk of bias rating tool was adopted to assess the risk of bias in individual studies and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guideline was employed to assess confidence in the body of evidence. RESULTS: A total 14 studies comprising four cohorts (13,155 cases among 372,802 exposed subjects), nine case-control and one case-referent studies of female subjects (39,462 cases and 20,739 controls) across seven countries and published between 2001 and 20 were included for review. Participants in the highest LAN exposure category were associated with higher risk of breast cancer in reference to those in the lowest (SRR: 1.12; 95% CI: 1.06-1.18; I2 = 39% for outdoor LAN, and SRR: 1.13; 95%CI: 1.05-1.21; I2 = 19% for indoor LAN). Pooled evidence identified relatively pronounced association of outdoor LAN exposure and breast cancer among women with estrogen receptor positive (ER+) tumor (SRR: 1.21; 95% CI: 1.04-1.40) and premenopausal status (SRR: 1.21; 95% CI: 1.06-1.37). The final rate of confidence in the body of evidence generated was graded as 'moderate' based on GRADE guideline. DISCUSSION: LAN exposure was consistently associated with higher breast cancer risk corroborating NTP's recommendations which anticipates excessive LAN as human carcinogen.

The nature of cities and the Covid-19 pandemic.

The virtual issue will only include the main essay.

Exposure to light at night (LAN) and risk of obesity: A systematic review and meta-analysis of observational studies.

BACKGROUND: There is emerging evidence of the association between light at night (LAN) exposure and weight gain. OBJECTIVE: We aim to conduct a systematic review and meta-analysis of observational studies on the association between LAN exposure and risk of obesity in human subjects. METHODS: Peer-reviewed observational studies were systematically searched from MEDLINE (EBSCO), Academic Search Complete (EBSCO), CINAHL Plus (EBSCO) and PubMed up to December 24, 2019. Random-effects models were developed to estimate the associations between LAN exposure and weight-related outcomes of overweight and obesity as measured by body mass index (BMI), waist circumference, waist-hip-ratio and waist-to-height-ratio. The I2 statistic was used to assess the degree of heterogeneity across studies. The National Toxicology Program's Office of Health Assessment and Translation (OHAT) risk of bias rating tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guideline were respectively employed to assess the risk of bias and to appraise the quality of the generated evidence. RESULTS: A total of 12 studies (three with longitudinal and nine of cross-sectional design) published between 2003 and 2019 were included for systematic review, while seven of them fulfilling the inclusion/exclusion criteria were included in the meta-analysis. A higher LAN exposure was significantly associated with 13% higher odds of overweight (BMI≥25 kg/m2) (Summary Odds Ratio; SOR: 1.13, 95% CI: 1.10-1.16) with low heterogeneity (I2 = 27.27%), and 22% higher odds of obesity (BMI≥30 kg/m2) (SOR: 1.22, 95% CI: 1.07-1.38) with substantial heterogeneity (I2 = 85.96%). Stratifying analyses by the levels of measurement of LAN exposures (macro-, meso- and micro-levels) and time of LAN measurement (including before and while sleeping) consistently produced robust estimates, with higher exposure to LAN being positively associated with poorer weight outcomes. Assessment of risk of bias identified substantial detection bias for exposure, with over half of the pooled studies employing subjective LAN measures. The overall evidence of the association between LAN exposure and risk of obesity was rated as 'moderate' as per the GRADE guideline. CONCLUSIONS: Exposure to LAN was reported to be a significant risk factor for overweight and obesity. Prospectively designed future studies with objectively measured multi-level LAN exposures and weight outcomes are required.

Exploring the Associations of Walking Behavior with Neighborhood Environments by Different Life Stages: A Cross-Sectional Study in a Smaller Chinese City.

Because of high population density and rapid urbanization, different human life stages have distinct growth experiences, leading to different lifestyles and age-spatial separation in the same neighborhood environment, particularly in smaller Chinese cities. The relationship of environment to physical activity may differ from western or larger Chinese cities. This study examined the associations of walking duration to the neighborhood environment and other factors, and explored the nuances of walking behavior for different life stages of adults in a smaller Chinese city, Yuncheng. An interviewer-administered questionnaire survey (n = 173) and face-to-face interviews (n = 19) were conducted in August 2017. Descriptive analysis and multiple linear regression were performed to describe walking motivations, sociodemographic characteristics, neighborhood environments, and their impacts on walking duration across three life stages. The quantitative findings were followed by interviews to validate and interpret them. Our results showed no positive associations of land-use mix (LUM) and residential density on walking duration, and even inverse associations of LUM-recreation and LUM-education for specific life stages were identified. Younger people's walking behavior was more related to consumption amenities distinct from those of older people. Our findings suggest that using walkable neighborhood policies (e.g., high residential density and land-use mix) to increase physical activity might be ineffective in smaller Chinese cities.