The Minhang Pediatric Biobank cohort study: protocol overview and baseline characteristics.

BACKGROUND: Little has been done to establish biobanks for studying the environment and lifestyle risk factors for diseases among the school-age children. The Minhang Pediatric Biobank (MPB) cohort study aims to identify factors associated with health and diseases of school-aged children living in the urban or suburban area of Shanghai. METHODS: This population-based cohort study was started in all sub-districts/towns of Minhang district of Shanghai in 2014. First-grade students in elementary school were enrolled during the time of their routine physical examinations, with self-administered questionnaires completed by their primary caregivers. Additional information was extracted from multiple health information systems. Urine and saliva samples were collected during the baseline survey and follow-up visits. RESULTS: At the end of 2014 academic year, a total number of 8412 children and their parents were recruited, including 4339 boys and 4073 girls. All the participants completed the baseline survey and physical examination, and 7128 urine and 2767 saliva samples were collected. The five most prevalent childhood diseases in this population were dental caries, bronchitis, pneumonia, asthma and overweight/obese. CONCLUSIONS: The MPB cohort has been successfully established, serving as a useful platform for future research relating to the genetic, environmental and lifestyle risk factors for childhood diseases.

Differential effects of size-specific particulate matter on frailty transitions among middle-aged and older adults in China: findings from the China Health and Retirement Longitudinal Study (CHARLS), 2015-2018.

BACKGROUND: This study aimed to assess the long-term effects of size-specific particulate matter (PM) on frailty transitions in middle-aged and older Chinese adults. METHODS: We included 13 910 participants ≥45 y of age from the China Health and Retirement Longitudinal Study (CHARLS) for 2015 and 2018 who were classified into three categories in 2015 according to their frailty states: robust, prefrail and frail. Air quality data were obtained from the National Urban Air Quality Real-time Publishing Platform. A two-level logistic regression model was used to examine the association between concentrations of PM and frailty transitions. RESULTS: At baseline, the total number of robust, prefrail and frail participants were 7516 (54.0%), 4324 (31.1%) and 2070 (14.9%), respectively. Significant associations were found between PM concentrations and frailty transitions. For each 10 µg/m3 increase in the 3-y averaged 2.5-µm PM (PM2.5) concentrations, the risk of worsening in frailty increased in robust (odds ratio [OR] 1.06 [95% confidence interval {CI} 1.01 to 1.12]) and prefrail (OR 1.07 [95% CI 1.01 to 1.13]) participants, while the probability of improvement in frailty in prefrail (OR 0.91 [95% CI 0.84 to 0.98]) participants decreased. In addition, the associations of PM10 and coarse fraction of PM with frailty transitions showed similar patterns. CONCLUSIONS: Long-term exposure to PM was associated with higher risks of worsening and lower risks of improvement in frailty among middle-aged and older adults in China.

Estimating the joint effect of household solid fuel use and social isolation on depression among middle-aged and older adults in China.

BACKGROUND: Household solid fuel use and social isolation are reported to increase the risk of depressive symptoms, but their joint effect has not yet been examined. This study aimed to explore the separate and joint effects of household solid fuel use and social isolation on depression. METHODS: We used data from the latest four waves (2011-2018) of the China Health and Retirement Longitudinal Study (CHARLS). Depression was defined as a score of ≥12 using the Center for Epidemiologic Studies Depression Scale (CES-D 10). Cox proportional hazards models were applied to explore the separate and joint associations of household solid fuel use and social isolation with incident depression. RESULTS: During the seven-year follow-up, 2793 (30.25 %) out of the 9232 participants were identified with depressive symptoms. Solid fuel use for household heating or cooking was significantly associated with more hazards of depressive symptoms after adjusting for potential confounders (cooking: HR = 1.280, 95 % CI = 1.175-1.394; heating: HR = 1.142, 95 % CI = 1.054-1.238). High social isolation at baseline was also a significant predictor of incident depressive symptoms (HR = 1.139, 95 % CI = 1.053-1.231). Participants exposed to both solid fuel use and high social isolation were found to have higher hazards of experiencing depressive symptoms than those exposed to none or only one of these two risk factors (heating: HR for 'solid fuel use + high social isolation'=1.308 versus HR for other groups = 1-1.185; cooking: HR for 'solid fuel use + high social isolation' = 1.430 versus HR for other groups = 1-1.255). CONCLUSION: Household solid fuel use and social isolation were separately and jointly associated with higher risks of incident depression. Appropriate interventions to reduce solid fuel use and social isolation are recommended to improve the psychological health among middle-aged and older adults in China.

Size-specific particulate matter and outpatient visits for allergic conjunctivitis in children: a time-stratified case-crossover study in Guangzhou, China.

This time-stratified case-crossover study aims to quantify the risk of allergic conjunctivitis (AC) associated with short-term exposure to PMs (i.e., PM1, PM2.5, PMc, and PM10) among children in Guangzhou, China. We collected data on children's daily AC outpatient visits from the Guangzhou Women and Children Medical Center during February 20, 2016 to December 31, 2018, and also extracted air pollution and meteorological data in the same time frame. We used conditional logistic regression model to estimate the associations between PMs and AC outpatient visits, and conducted subgroup analyses stratified by sex, age, and season. During the study period, we recorded 39,330 children's outpatient visits for AC, including 27,638 boys and 11,692 girls. The associations between PMs and AC were general linear with no clear threshold, which were largest at the current days but remained positive for lag 1 to 3 days. For every 10 µg/m3 increase in daily PM1, PM2.5, PMc, and PM10 concentrations, the estimated risks of AC outpatient visits at the current days increased by 2.5% (OR = 1.025, 95% CI: 1.011-1.039), 1.8% (OR = 1.018, 95% CI: 1.009-1.027), 2.1% (OR = 1.021, 95% CI: 1.004-1.039), and 1.3% (OR = 1.013, 95% CI: 1.007-1.020), respectively. In addition, our stratified analyses revealed that girls and children aged 1 to 6 years were more sensitive to PM exposure, and the PM-associated risks for AC were more apparent in autumn and winter. Our study suggests that short-term exposure to PMs may induce AC in children.

Fetal Exposure to Air Pollution in Late Pregnancy Significantly Increases ADHD-Risk Behavior in Early Childhood.

BACKGROUND: Air pollution nowadays has seriously threatened the health of the Chinese population, especially in the vulnerable groups of fetuses, infants and toddlers. In particular, the effects of air pollution on children's neurobehavioral development have attracted widespread attention. Moreover, the early detection of a sensitive period is very important for the precise intervention of the disease. However, such studies focusing on hyperactive behaviors and susceptible window identification are currently lacking in China. OBJECTIVES: The study aims to explore the correlation between air pollution exposure and hyperactive behaviors during the early life stage and attempt to identify whether a susceptible exposure window exists that is crucial for further precise intervention. METHODS: Based on the Longhua Child Cohort Study, we collected the basic information and hyperactivity index of 26,052 children using a questionnaire conducted from 2015 to 2017, and the Conners' Parent Rating Scale-revised (CPRS-48) was used to assess hyperactive behaviors. Moreover, the data of air pollution concentration (PM10, PM2.5, NO2, CO, O3 and SO2) were collected from the monitoring station between 2011 to 2017, and a land-use random forest model was used to evaluate the exposure level of each subject. Furthermore, Distributed lag non-linear models (DLNMs) were applied for statistic analysis. RESULTS: The risk of child hyperactivity was found to be positively associated with early life exposure to PM10, PM2.5 and NO2. In particular, for an increase of per 10 µg/m3 in PM10, PM2.5 and NO2 exposure concentration during early life, the risk of child hyperactivity increased significantly during the seventh month of pregnancy to the fourth month after birth, with the strongest association in the ninth month of pregnancy (PM10: OR = 1.043, 95% CI: 1.016-1.071; PM2.5: OR = 1.062, 95% CI: 1.024-1.102; NO2: OR = 1.043, 95% CI: 1.016-1.071). However, no significant associations among early life exposure to CO, O3 and SO2 and child hyperactive behaviors were observed. CONCLUSIONS: Early life exposure to PM10, PM2.5 and NO2 is associated with an increased risk of child ADHD-like behaviors at the age around 3 years, and the late-prenatal and early postnatal periods might be the susceptible exposure windows.

Associations between conjunctivitis and ambient PM2.5 and physical activity: A nationwide prospective cohort study.

BACKGROUND: Currently, there is no evidence of fine particulate matter pollution (PM2.5) altering the relationship between physical activity (PA) and the risk of conjunctivitis. METHODS: Based on the UK Biobank study, we included 308,507 participants aged 40-69 years at baseline (2006 to 2010) and prospectively followed up for conjunctivitis diagnosis till 2020. Annual concentrations of PM2.5 in 2010 were estimated for each participant using Land Use Regression models. PA levels during work and leisure time were reported via the International Physical Activity Questionnaire at baseline. We used Cox proportional hazards models to examine the associations of PM2.5 and PA with incident conjunctivitis, as well as their interaction at both multiplicative and additive scales. RESULTS: During the 11.6 years of follow up, we identified 4002 incident conjunctivitis cases. High-PA (≥3000 metabolic equivalent of task [MET]-mins/week) was associated with lower risk of conjunctivitis (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.73-0.86) compared to low-PA (0 to <600 MET-mins/week), while every 1 µg/m3 increment in PM2.5 was associated with a 16% higher risk of conjunctivitis (HR = 1.16, 95% CI: 1.09-1.23). We did not observe statistically significant interactions between PM2.5 and PA on their associations with conjunctivitis. CONCLUSION: Habitual PA and PM2.5 exposure were oppositely related to incident conjunctivitis. The benefits of PA remain in people irrespective of exposure to air pollution.

High-Temperature Soup Foods in Plastic Packaging Are Associated with Phthalate Body Burden and Expression of Inflammatory mRNAs: A Dietary Intervention Study.

Plastic packaging material is widely used to package high-temperature soup food in China, but this combination might lead to increased exposure to phthalates. The health effects and potential biological mechanisms have not been well studied. This study aimed to examine urinary phthalate metabolites and the expression of inflammatory cytokines in the blood before, during, and after a "plastic-packaged high-temperature soup food" dietary intervention in healthy adults. The results showed that compared with those in the preintervention period, urinary creatinine-adjusted levels of monomethyl phthalate (MMP), mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MIBP), and total phthalate metabolites in the intervention period were significantly higher, with increases of 71.6, 41.8, 38.8, and 29.8% for MMP, MBP, MIBP, and the total phthalate metabolites, respectively. After intervention, the mean levels of IL-1ß, IL-4, and TNF-α mRNA increased by 19.0, 21.5, and 25.0%, respectively, while IL-6 and IFN-γ mRNA decreased by 24.2 and 32.9%, respectively, when compared with the preintervention period. We also observed that several phthalates were associated with the mRNA or protein expression of IL-8, TNF-α, and IL-10. Therefore, consumption of plastic-packaged high-temperature soup food was linked to increased phthalate exposure and might result in significant changes in mRNA expression of several inflammatory cytokines.

Study design, general characteristics of participants, and preliminary findings from the metabolome, microbiome, and dietary salt intervention study (MetaSalt).

BACKGROUND: High sodium intake is an important risk factor for hypertension and cardiovascular disease. However, the association between gut microbiota composition and metabolomic profiles with dietary sodium intake and blood pressure (BP) is not well-understood. The metabolome, microbiome, and dietary salt intervention (MetaSalt) study aimed to investigate microbial and metabolomic profiles related to dietary sodium intake and BP regulation. METHODS: This family-based intervention study was conducted in four communities across three provinces in rural northern China in 2019. Probands with untreated prehypertension or stage-1 hypertension were identified through community-based BP screening, and family members including siblings, offspring, spouses, and parents were subsequently included. All participants participated in a 3-day baseline examination with usual diet consumption, followed by a 10-day low-salt diet (3 g/d of salt or 51.3 mmol/d of sodium) and a 10-day high-salt diet (18 g/d of salt or 307.8 mmol/d of sodium). Differences in mean BP levels were compared according to the intervention phases using a paired Student's t-test. RESULTS: A total of 528 participants were included in this study, with a mean age of 48.1 years, 36.7% of whom were male, 76.8% had a middle school (69.7%) or higher (7.1%) diploma, 23.4% had a history of smoking, and 24.4% were current drinkers. The mean arterial pressure at baseline was 97.2 ± 10.5 mm Hg for all participants, and significantly decreased during the low-salt intervention (93.8 ± 9.3, P < 0.0001) and subsequently increased during the high-salt intervention (96.4 ± 10.0, P < 0.0001). CONCLUSIONS: Our dietary salt intervention study has successfully recruited participants and will facilitate to evaluate the effects of gut microbiota and metabolites on BP regulation in response to sodium burden, which will provide important evidence for investigating the underlying mechanisms in the development of hypertension and subsequent cardiovascular diseases. TRIAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registry database (ChiCTR1900025171).

Disease burden and attributable risk factors of respiratory infections in China from 1990 to 2019.

BACKGROUND: There was lack of data on the burdens and trends of upper and lower respiratory infections (URIs and LRIs) over the past three decades in China. METHODS: We estimated the incidence, mortality, and disability-adjusted life years (DALYs) due to upper and lower respiratory infections (URIs and LRIs) and attributable risk factors in China by a systematic analysis of the Global Burden of Disease 2019 study. Incidence, mortality, and DALYs were stratified by sex, age, and province. Risk factors for respiratory infections were analyzed from exposure data. FINDINGS: The age-standardized incidence rates of URIs and LRIs were 179,077 and 3926 per 100,000 persons in 2019, with a 7•52% and 35•07% decrease from 1990, respectively. Moreover, 2801 and 185,264 persons died of URIs and LRIs in 2019, respectively. DALYs for URIs and LRIs also decreased from 1,516,727 in 1990 to 928,617 in 2019 and from 38,278,504 in 1990 to 4,020,676 in 2019. The burden of URIs and LRIs were generally similar in males and females, but relatively higher in the new-borns and the elderly. Child malnutrition and low birth weight were the most important cause of age-standardized DALYs of LRIs and URIs, respectively. INTERPRETATION: Future URI and LRI prevention strategies should focus on the maternal and child health, air pollution, and tobacco control, especially in young children and the elderly population. FUNDING: National Key R&D Program of China (2018YFA0606200); National Natural Science Foundation of China (82041021); Fundamental Research Funds for the Central Universities (20ykpy86) and Guangdong Basic and Applied Basic Research Foundation (2019A1515110003); Bill & Melinda Gates Foundation (No.: INV-006371).

Association between greater residential greenness and decreased risk of preschool myopia and astigmatism.

OBJECTIVE: Rapid urbanization has led to reduced greenness in many areas, this has been linked to adverse health outcomes. The aim was to determine the association between residential greenness experienced during very early childhood with preschool myopia and astigmatism and to explore the potential mediating role of screen time on any associations. METHOD: Information regarding socio-demographic characteristics, home address, screen time during early childhood, and refraction data from vision screenings of 53,575 preschoolers from Longhua Child Cohort Study were collected via questionnaires. Residential greenness was calculated as the average of satellite-derived Normalized Difference Vegetation Index in buffers of 100, 250, and 500 m around each child's home address. Logistic and linear regression models were used to examine the relationships between residential greenness, screen time, and preschool myopia and astigmatism. RESULT: The mean (SD) age of the 53,575 preschoolers was 5.0 (0.7) years, and 24,849 (46.4%) were girls. A total of 1236 (2.3%) preschoolers had myopia and 5347 (10.0%) had astigmatism. In the adjusted model, a higher neighborhood greenness level within 100 m buffers around the home address was associated with decreased risk of myopia (adjusted odds ratios (AOR): 0.62, 95% confidence interval (CI): 0.38-0.99), and higher neighborhood greenness levels within 100, 250, and 500 m decreased the risk of astigmatism, and their AORs (95% CIs) were 0.55 (0.43-0.70) for 100 m, 0.59 (0.41-0.83) for 250 m, 0.61 (0.42-0.90) for 500 m, respectively. Greater screen time during early childhood increased the risk of myopia (AOR = 1.33) and astigmatism (AOR = 1.23). Reduction in screen time fully mediated the benefits of greater residential greenness on preschool myopia, but partially mediated that on preschool astigmatism (p < 0.05). CONCLUSION: Higher residential greenness reduces the risk of preschool myopia and astigmatism; the benefits of residential greenness were mediated through reduced daily screen time.

Combination Effect of Outdoor Activity and Screen Exposure on Risk of Preschool Myopia: Findings From Longhua Child Cohort Study.

Evidence regarding screen use and outdoor activity during very early childhood (i. e., from aged 1 to 3 years) and their potential combined links to the later preschool myopia is limited. This information is needed to release effective public health messages and propose intervention strategies against preschool myopia. We collected information regarding very early childhood screen use, outdoor activity and the kindergartens vision screenings of 26,611 preschoolers from Longhua Child Cohort Study by questionnaires. Logistic regression models were used to examine the associations between reported outdoor activity, screen use from 1 to 3 years of age, and preschool myopia. Throughout very early childhood, from 1 to 3 years, the proportion of children exposed to screens increased (from 35.8 to 68.4%, p < 0.001), whereas the proportion of children who went outdoors ≥7 times/week (67.4-62.1%, p < 0.001) and who went outdoors for ≥60 min/time (53.3-38.0%, p < 0.001) declined. Exposure to fixed screen devices [adjusted odds ratio (AOR) = 2.66, 95% confidence interval (CI) = 2.09-3.44], mobile screen devices (AOR = 2.76, 95% CI = 2.15-3.58), and limited outdoor activity (AOR = 1.87, 95% CI = 1.42-2.51) during early childhood were associated with preschool myopia. Among children whose parents were myopic, the interactions between outdoor activity and fixed or mobile screen use on later preschool myopia were significant; the ORs and 95% CI were 3.34 (1.19-9.98) and 3.04 (1.06-9.21), respectively. Our findings suggest the possibility that the impact of screen exposure during early childhood on preschool myopia could be diminished by outdoor activity for children whose parents have myopia.

Improvement in life expectancy for ischemic heart diseases by achieving daily ambient PM2.5 standards in China.

BACKGROUND: The potential impacts of daily ambient fine particulate pollution (PM2.5) exposure on year of life lost (YLL) due to ischemic heart diseases (IHD) remain uncertain. We aimed to estimate the improvement in IHD-related life expectancy by attaining the daily air quality standards of ambient PM2.5 in China. METHODS AND RESULTS: This study was based on daily mortality data covering 96 Chinese cities from 2013 to 2016. Regional- and national-associations between IHD-related YLLs and daily PM2.5 were estimated by generalized additive models. We further evaluated the IHD-related avoidable YLLs with an assumption that the daily PM2.5 was below the ambient air quality standards of World Health Organization (WHO) and China, and calculated the improvement of life expectancy by dividing the avoidable YLLs by the overall number of IHD mortality. We totally recorded 1,485,140 IHD deaths from 2013 to 2016. At the national level, we found a positive association between IHD-related YLLs and daily PM2.5. Per 10 µg/m3 increment of four-day averaged ambient PM2.5 related to an increase of 0.40 IHD-related YLLs (95% CI: 0.28, 0.51). By achieving the WHO's air quality guideline, we estimated that an averaged number of 1346.94 (95% CI: 932.61, 1761.27) YLLs can be avoided for the IHD deaths in each city. On average, the life expectancy can be improved by 0.15 years (95% CI: 0.11, 0.19) for each death. CONCLUSIONS: Our study provides a nationwide picture of the life expectancy improvements by reaching the daily PM2.5 standards in China, indicating that people can live longer in an environment with higher air quality.

Prolonged Life Expectancy for Those Dying of Stroke by Achieving the Daily PM2.5 Targets.

This time-series study collects data on stroke-related mortality, years of life lost (YLL), air pollution, and meteorological conditions in 96 Chinese cities from 2013 to 2016 and proposes a three-stage strategy to generate the national and regional estimations of avoidable YLL, gains in life expectancy and stroke-related population attributable fraction by postulating that the daily fine particulate matter (PM2.5) has been kept under certain standards. A total of 1 318 911 stroke deaths are analyzed. Each 10 µg m-3 increment in PM2.5 at lag03 is associated with a city-mean increase of 0.31 (95% CI: 0.19, 0.44) years of life lost from stroke. A number of 914.11 (95% CI: 538.28, 1288.94) years of city-mean life lost from stoke could be avoided by attaining the WHO's Air Quality Guidelines (AQG) (25 µg m-3). Moreover, by applying the AQG standard, 0.11 (0.08, 0.15) years of life lost might be prevented for each death, and about 0.91% (95% CI: 0.62%, 1.19%) of the total years of life lost from stroke might be explained by the daily excess PM2.5 exposure. This study indicates that stroke patients can have a longer life expectancy if stricter PM2.5 standards are put in place, especially ischemic stroke patients.

Differentiating the effects of ambient fine and coarse particles on mortality from cardiopulmonary diseases: A nationwide multicity study.

BACKGROUND: Both inhalable particles (PM10) and fine particles (PM2.5) are regulated in various countries mainly due to their adverse health effects. However, there is increasing evidence that PM2.5 might be responsible for these effects and coarse particles (PMc) plays little role in adverse health effects, if so, it might be not necessary to monitor PM10. METHODS: In this study, we conducted a time-series analysis using a generalized additive model to explore the effects of PM2.5, PMc, and PM10 on mortality from ischemic heart disease (IHD) and chronic obstructive pulmonary disease (COPD) in 96 Chinese cities during 2013-2016. The mortality number and attributable fraction were further estimated using the national air quality standard and WHO's guideline as the reference. RESULTS: We observed significant effects of PM2.5 on IHD and COPD mortality; each 10 ug/m3 increase in lag01 PM2.5 was associated with a 0.26% (95% CI: 0.17%, 0.34%) increase in IHD mortality and a 0.19% (95% CI: 0.09%, 0.29%) increase in COPD mortality. We also found significant effects of PMc and PM10 on mortality from IHD and COPD, but the magnitudes of effects were weaker than those of PM2.5. The results were robust when adjusting for co-pollutants and altering model parameters. We further estimated that about 1.27% (95% CI: 0.29%, 2.30%) of IHD mortality and 1.25% (95% CI: 0.08%, 2.46%) of COPD mortality could be attributable to PM2.5 exposure using WHO's guideline (25 ug/m3) as a reference, corresponding to 15,337 (95% CI: 3,375, 27,842) mortalities from IHD and 5,653 (95% CI: 379, 11,152) COPD mortalities in the 96 cities. Across all of China, almost fifty thousand cases of IHD mortality and twenty thousand cases of COPD mortality might be avoidable if the PM2.5 concentration declined to the WHO guideline. CONCLUSIONS: Our study indicates that short-term exposure to PM2.5 could be an important risk factor of mortality from IHD and COPD, and substantial cardiopulmonary mortality could be avoidable by reducing daily PM2.5 concentrations. It is nonnegligible to consider the role of PMc in triggering in cardiopulmonary mortality. And it could be necessary to continue monitoring PM10 in the study regions due to the adverse effects of PMc.

Neighborhood greenness associated with chronic obstructive pulmonary disease: A nationwide cross-sectional study in China.

Differential findings have been reported on the association between neighborhood greenness and chronic obstructive pulmonary disease (COPD). The underlying reasons might be the different types of vegetation and the diagnosis methods used in different studies. In this nationwide cross-sectional study in China, we examined the linkage between neighborhood greenness and COPD prevalence among 66,752 adults aged 40 years and above. Neighborhood greenness was estimated using the normalized difference vegetation index (NDVI) based on satellite imagery within buffers of 100, 300, 500, 1000, 2000, 3000 and 5000 m of residential community of the participants. COPD was defined according to the 2017 Global Initiative for Chronic Obstructive Lung Disease lung function criteria. A two-level logistic regression model was applied to estimate the associations. Finally, 9134 adults were classified as COPD. We observed significant positive associations between neighborhood greenness and COPD prevalence. The odds ratio for each interquartile range increase in NDVI within 100 m buffer was 1.08 (95% CI: 1.01, 1.15) after adjustment for potential confounders. Consistent associations were observed across all other NDVI buffer sizes. Stratified analyses revealed that younger adults (40-65 years) and urban residents might be the vulnerable subpopulations. Further regional analyses found that residents from the Northeastern and Northern China were more likely to have this association. Our results indicated that neighborhood greenness might be one risk factor of COPD prevalence. Our study have important public health implications for allocating the surrounding green spaces among living areas, especially for those with respiratory illness; however, the findings and the underlying mechanisms warrant further examinations in longitudinal settings.

Ambient air pollution exposure associated with glucose homeostasis during pregnancy and gestational diabetes mellitus.

BACKGROUND: To investigate the effects of air pollution exposure during pregnancy on the indicators of glucose homeostasis and gestational diabetes mellitus (GDM). METHODS: We conducted a birth cohort study in Foshan, China during 2015-2019. Oral glucose tolerance test (OGTT) was administered to each participant during pregnancy. GDM was defined according to the International Association of Diabetes and Pregnancy Study Groups criteria (IADPSG). Air pollutant (fine particulate matter (PM2.5), particulate matter with an aerodynamic diameter of 10 µm or less (PM10), sulfate dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3)) concentrations from the air monitoring stations in Foshan were used to estimate individual air pollutant exposure during the first two trimesters. Linear and logistic regression models were employed to estimate the associations between air pollution exposure during the first two trimesters and OGTT glucose levels and GDM. RESULTS: Of 12,842 pregnant women, 3055 (23.8%) had GDM. A 10 µg/m3 increase in PM2.5, PM10 and SO2 during trimester 1, trimester 2 and two trimesters were associated with 0.07 mmol/L to 0.29 mmol/L increment in OGTT-fasting glucose levels in single-pollutant model. A 10 µg/m3 increase in NO2 and O3 during two trimesters were associated with 0.15 mmol/L and 0.12 mmol/L decrease in OGTT-fasting glucose in single-pollutant model. However, no significant or weaker effects of O3 during two trimesters on OGTT-fasting glucose were observed in two-pollutant models. Moreover, exposure to PM2.5, PM10 and SO2 were associated with increased risk of GDM in both single- and two-pollutant models. CONCLUSIONS: Our study suggests PM2.5, PM10 and SO2 exposure during the first two trimesters might increase the risk of GDM.

The mediation effect of maternal glucose on the association between ambient air pollution and birth weight in Foshan, China.

Maternal blood glucose level is associated with fetal growth, therefore, its role in the associations between air pollution and birth weight deserves investigation. We examined the mediation effect of maternal blood glucose on the associations between maternal air pollution exposure and birth weight. A total of 10,904 pregnant women in Foshan, China during 2015-2019 were recruited. Oral glucose tolerance test (OGTT) was administered to each participant after late trimester 2. Air pollution data at the monitoring stations in residential districts was used to estimate exposures of each participant during trimester 1 and trimester 2. Mixed-effects linear models were used to estimate the associations between air pollution and birth weight. After controlling for ten covariates, the direct effect of PM2.5 and SO2 (each 10 µg/m3 increment) on birth weight was -15.7 g (95% CI: -29.4, -4.8 g) and -83.6 g (95% CI: -134.8, -33.0 g) during trimester 1. The indirect effect of PM2.5 and SO2 (each 10 µg/m3 increment) on birth weight by increasing maternal fasting glucose level was 6.6 g (95% CI: 4.6, 9.1 g) and 22.0 g (95% CI: 4.1, 44.0 g) during trimester 1. Our findings suggest that air pollution might affect the birth weight through direct and indirect pathway, and the indirect effect might be mediated by maternal blood glucose.

How longer can people live by achieving the daily ambient fine particulate pollution standards in the Pearl River Delta region, China?

BACKGROUND: Previous research has reported the effects of long-term fine particulate matter (PM2.5) pollution on years of life lost (YLL), but these effects may not represent the full impact. This study aims to estimate potential benefits in life time from adhering to daily ambient PM2.5 concentration standards/guidelines. METHODS: This study evaluated the relationship between daily ambient PM2.5 level and YLL using a two-stage approach with generalized additive models and meta-analysis. Potential life expectancy gains were then estimated by presuming that daily PM2.5 levels were in compliance with the Chinese and WHO standards. In addition, the attributable fraction of YLL due to excess PM2.5 exposure was also calculated. RESULTS: During 2013-2016, 459,468 non-accidental deaths were recorded in the six cities of Pearl River Delta, China. Each 10 µg/m3 increment in four-day average (lag03) level of PM2.5 was related to an increment of 13.31 [95% confidence interval (CI): 5.74, 20.87] years of life lost. Implementation of the WHO guidelines might avoid 180,980.83 YLLs (95% CI: 78,116.07, 283,845.60), which corresponded to 0.39 (95% CI: 0.17, 0.62) years of increased life time per death. Additionally, an estimated 0.15% (95% CI: 0.06%, 0.23%) or 2.04% (95% CI: 0.88%, 3.20%) of YLLs could be attributed to PM2.5 exposures higher than the Chinese or WHO guidelines, respectively. CONCLUSIONS: This study suggests that people might live longer by controlling daily PM2.5 concentration and highlights the need to adopt stricter standards in China.

Screen Exposure during Early Life and the Increased Risk of Astigmatism among Preschool Children: Findings from Longhua Child Cohort Study.

Screen media usage has become increasingly prevalent in daily life with children being exposed to screens at an early age. This is a growing public health concern with evidence linking screen exposure to detrimental health outcomes, whereas relationship between screen exposure and the presence of astigmatism among preschoolers remains unknown, thus we aimed to resolve this issue. During the 2017 survey of the Longhua Child Cohort Study, data of 29,595 preschoolers were collected via a caregiver-reported questionnaire regarding socio-demographics, screen exposure and refraction. Cox regression models were adopted to generate adjusted prevalence ratios (APR) and 95% confidence intervals (CI) to estimate the association between early screen exposure and astigmatism. 28,029 preschoolers were included in the final analysis. After adjustment for potential confounders, screen exposure during early life was significantly associated with the increased risk of astigmatism (APR and 95% CI: 2.25, 1.76-2.88), and the greatest risk was observed in the period from birth to 1-year (APR and 95% CI: 3.10, 2.41-3.98). The risk of astigmatism increased with both the total years of exposure and the average daily duration of screen exposure. Our findings suggested that preschoolers who were exposed to screens during early life might have an increased risk of astigmatism.

Associations Between Screen Exposure in Early Life and Myopia amongst Chinese Preschoolers.

This study aimed to explore the association between screen exposure in early life and preschool myopia. During the baseline survey of the Longhua Child Cohort Study (LCCS), data of 29,595 preschoolers were collected via a caregiver-reported questionnaire regarding children's socio-demographic characteristics, visual status, screen exposure and relevant parental information. Data of 26,433 preschoolers with normal eyesight or myopia were included in the analysis and cox regression modelling was employed to assess the associations. Results suggested the hypothesis that screen exposure in early life could be significantly and positively associated with preschool myopia, and in agreement with this hypothesis was the association being strengthened with the increasing daily exposure duration and total years of exposure; in the stratification analysis based on the presence of parental myopia, these associations still existed, and the strength of associations was stronger in preschoolers with myopic parents than those without. Moreover, a statistically significant association was only observed between initial screen exposure that occurred during 0-1-years old and myopia for preschoolers without myopic parents, while the significant associations were observed between initial screen exposure that occurred during 0-1, 1-2, 2-3, and after 3 years old and myopia for preschoolers who had myopic parents, with the strongest association found in the group of children initially exposed to electronic screens during 0-1 year old. Thus our findings indicated the hypothesis that screen exposure in early life might be associated with the occurrence of preschool myopia, and that the postnatal first year might be the sensitive period for the association. However, it is premature to conclude that early screen time leads to myopia with current data. Further longitudinal studies performed with cycloplegia are necessary to verify the hypothesis and shed light on the more urgent question whether early screen exposure contributes to the later myopia epidemic of school-aged children.