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With the world's population steadily shifting toward urban living, children's engagement with the natural environment seems to be diminishing. This raises significant concerns about the influence of urban greenspaces on the cardiovascular health of children. To assess the association between urban greenspaces exposure and blood pressure (BP) in Chinese primary schoolchildren. This prospective cohort study used data from the Children's growth environment, lifestyle, physical, and mental health development (COHERENCE) project in Guangzhou, China. Participants included 164,853 primary schoolchildren starting from 2016/17 to 2019/20 academic year. We assessed the surrounding greenspaces at home and school by using Sentinel-2 satellite data on the normalized difference vegetation index. Prehypertension and hypertension status were defined with BP above 90th to less than the 95th percentile, at or above the 95th percentile, respectively. The association of surrounding greenness with children's BP levels and risk of prehypertension/hypertension were examined using linear mixed-effects models and Cox proportional hazards model. Among 164,853 eligible children aged 7.21 (0.74) years, 89,190 (54.1%) were boys. Our results showed that average systolic and diastolic BP increased by 0.48 and 0.42 standard deviations, respectively, over the 3-year follow-up. We identified 23,225 new cases of prehypertension and 35,067 of hypertension status. An interquartile range increase both in home-, school- and home-school NDVI 100m was significantly associated with a reduction of 0.018–0.037 in BP z-scores and a 2.7%–7.6% lower risk of hypertension. Additionally, family socioeconomic status modified the impact of home-school greenness on BP levels. Air pollution exhibited mediating effects solely in school-greenness-BP associations, while physical activity and children's BMI mainly mediated the relationships between home-greenness and BP. The findings of this large cohort study suggest that surrounding greenspaces are associated with lower BP levels and a decreased risk of prehypertension and hypertension in Chinese schoolchildren. [Display omitted] • Location-specific greenspaces (home, school, and combined) were assessed. • Greenspaces were adverse associated with high blood pressure status. • Air pollution, physical activity, and BMI may mediate above these associations. • Location-specific greenness may emphasize distinct pathways related to BP. • Children with lower socioeconomic status obtain more benefit from greenspaces. [ABSTRACT FROM AUTHOR]

Air pollution exposures are increasingly suspected to influence the development of childhood adiposity, especially focusing on outdoor exposure, but few studies investigated indoor exposure and childhood obesity. We aimed to examine the association between exposure to multiple indoor air pollutants and childhood obesity in Chinese schoolchildren. In 2019, we recruited 6499 children aged 6–12 years from five Chinese elementary schools in Guangzhou, China. We measured age-sex-specific body mass index z score (z-BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) on standard procedures. Four different indoor air pollution (IAP) exposures, including cooking oil fumes (COFs), home decoration, secondhand smoke (SHS), and incense burning, were collected by questionnaire and then converted into an IAP exposure index with four categories. Association between indoor air pollutants and childhood overweight/obesity as well as four obese anthropometric indices were assessed by logistic regression models and multivariable linear regression models, respectively. Children exposed to ≥3 types of indoor air pollutants had higher z-BMI (coefficient [β]:0.142, 95% confidence interval [CI]:0.011–0.274) and higher risk of overweight/obesity (odd ratio [OR]:1.27, 95%CI:1.01–1.60). And a dose-response relationship was discovered between the IAP exposure index and z-BMI as well as overweight/obesity (p for trend <0.05). We also found that exposure to SHS and COFs was positively associated with z-BMI and overweight/obesity (p < 0.05). Moreover, there was a significant interaction between SHS exposure and COFs on the higher risk of overweight/obesity among schoolchildren. Boys appear more susceptible to multiple indoor air pollutants than girls. Indoor air pollution exposures were positively associated with higher obese anthropometric indices and increased odds of overweight/obesity in Chinese schoolchildren. More well-designed cohort studies are needed to verify our results. • A total of 6753 schoolchildren aged 6–12 years from Guangzhou, China was included. • Multiple indoor air pollution exposures were positively associated with childhood obesity and obese anthropometric indices. • Secondhand smoke exposure interacts withcooking oil fumes exposure in association with childhood overweight/obesity. • Multiple indoor air pollution exposures for boys have higher z-BMI. [ABSTRACT FROM AUTHOR]

Previous studies have indicated that exposure to green space may benefit human health. However, the available evidence concerning the effects of greenness, especially school-based greenness, on pediatric obesity is scarce. To explore the association between school-based greenness and adiposity in children and adolescents in China. We conducted a nationwide cross-sectional study of 56,620 children and adolescents (aged 6–18 years) in seven provinces/municipalities across China. School-based greenness was assessed using satellite-derived Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) within 100-, 500-, and 1000-m circular buffers around each school's address. Generalized linear mixed regression models were used to estimate associations of greenness with BMI z-scores (zBMI), waist circumference, and prevalent overweight/obesity. We also explored the potential mediating role of ambient air pollution and physical activity in the greenness-adiposity associations. In the adjusted model, an IQR increase in NDVI -1000m was associated with lower zBMI (β: -0.11, 95% confidence interval[CI]: -0.13,-0.09) and waist circumference (β: -0.64, 95%CI: -0.78,-0.50). Consistently, an IQR increase in NDVI -100m , NDVI -500m , NDVI -1000m was associated with 7–20% lower odds of overweight/obesity in the adjusted models. Air pollutants mediated 6.5–29.1% of the association between greenness and zBMI. No significant mediation effect was observed for physical activity. Higher school-based greenness levels were associated with lower zBMI, waist circumference, and lower odds of overweight and obesity in children and adolescents. Ambient air pollutants may partially mediate the greenness-adiposity associations. Image 1 • This study was conducted in 56,620 Chinese schoolchildren aged 6–18 years. • School-based greenness was negatively associated with pediatric obesity. • PM 2.5 may partially medicated the association between greenness and pediatric obesity. [ABSTRACT FROM AUTHOR]

Greenness exposure may lower blood pressure. However, few studies of this relationship have been conducted with children and adolescents, especially in low and middle-income countries. To evaluate associations between greenness around schools and blood pressure among children and adolescents across China. We recruited 61,229 Chinese citizens aged 6–18 years from 94 schools in a nationwide cross-sectional study in seven Chinese provinces/province-level municipalities. Participants' blood pressures and hypertension were assessed with standardized protocols. Greenness levels within 500 m and 1,000 m of each school were estimated with three satellite-based indices: vegetation continuous fields (VCF), normalized difference vegetation index (NDVI), and soil adjusted vegetation index (SAVI). Generalized linear mixed models were used to evaluate associations between greenness and blood pressure, greenness and prevalent hypertension, using coefficient and odds ratio respectively. Stratified analyses and mediation analyses were also performed. One interquartile range increase in greenness was associated with a 17%–20% reduced prevalence of hypertension for all measures of greenness (odds ratios for VCF 500m = 20% (95% CI:18%, 23%); for NDVI 500m = 17% (95% CI:13%, 21%); and for SAVI 500m = 17% (95% CI: 13%, 20%). Increases in greenness were also associated with reductions in systolic blood pressure (0.48–0.58 mmHg) and diastolic blood pressure (0.26–0.52 mmHg). Older participants, boys, and urban dwellers showed stronger associations than their counterparts. No evidence of mediation was observed for air pollution (i.e., NO 2 and PM 2.5) and body mass index. Higher greenness around schools may lower blood pressure levels and prevalent hypertension among Chinese children and adolescents, particularly in older subjects, boys, and those living in urban districts. Further studies, preferably longitudinal, are needed to examine causality. • This is one of the few studies to assess greenness and blood pressure in children. • We explored this topic in a large Chinese children population (n = 61,229). • Higher greenness levels were associated with lower blood pressure levels. • Stronger associations were observed in boys, being older, or living in cities. [ABSTRACT FROM AUTHOR]