Associations of long-term exposure to ambient air pollution and physical activity with insomnia in Chinese adults

Association between exposure to air pollution and risk of Dyssomnia: a systematic review and meta-analysis

BACKGROUND

Typically affecting people's quality of life, dyssomnia is among the most prevalent chronic illnesses worldwide. A positive correlation between air pollution and dyssomnia has been demonstrated by epidemiological research. However, no meta-analyses evaluating the relationship between the prevalence of dyssomnia in people of all ages and air pollutants (PM2.5, PM10, NO2, SO2, and O3) were found.

OBJECTIVES

Conduct a meta-analysis utilizing data from current studies (until 2024) to provide reliable insights into the relationship between air pollution exposure and the likelihood of dyssomnia prevalence.

METHODS

We systematically searched three databases for studies on air pollution and dyssomnia up to January 15, 2024. Random-effects models were used to estimate the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analyses, funnel plots, and meta-regression analyses were also performed.

RESULTS

There were 11 studies from 4 different nations that involved 3,328,183 participants in total. The odds ratios (ORs) for PM2.5 and PM10 were 1.29 (1.16-1.44) and 1.13 (1.03-1.23) per 10 µg/m3 increase in pollutants, respectively. The OR per 10 µg/m3 increment of gaseous pollutants were 1.06 (1.00-1.12) for NO2 and 1.16 (1.04-1.31) for O3. No significant association was observed between SO2 and dyssomnia. Adults are more sensitive to air pollution than children or adolescents for that the effects of PM2.5、PM10 and SO2 were significantly stronger in adults than children or adolescents. The effect of air pollution on dyssomnia was more significant in developed countries than in developing countries. There was a difference in the subgroup test for PM10 between developed and developing countries.

CONCLUSION

This meta-analysis implies the relationship between the air pollution and dyssomnia. Economic status and age may influence the effect. It was suggested to provide guidance for disease prevention and explored potential avenues for further research.

Nitrogen dioxide exposure attenuates or even reverses the association between physical activity and fasting plasma glucose levels in non-diabetic elderly Chinese adults

BACKGROUND

The combined effects of physical activity (PA) and nitrogen dioxide (NO2) on fasting plasma glucose (FPG) levels have rarely been studied. This study aimed to examine whether long-term exposure to NO2 attenuates the association between PA and FPG levels in non-diabetic older adults.

METHODS

A total of 2600 non-diabetic elderly Chinese adults were included in this cross-sectional study. PA data were collected using the International Physical Activity Questionnaire (IPAQ). The Space-Time Extra-Trees model was utilized to estimate the annual concentration of NO2. General linear regression models were used to assess independent and interaction associations of long-term exposure to NO2 and PA with FPG levels. An interaction plot was employed to enhance the visual representation of the interaction.

RESULTS

A 0.32 µg/m3 increase in the 3-year average NO2, corresponding to one interquartile range (IQR), was positively associated with FPG levels (β = 0.099 mmol/L, 95% CI: 0.069-0.130). PA exhibited a negative, albeit non-significant, association with FPG levels (β = -0.027 mmol/L, 95% CI: -0.069, 0.015). A statistically significant interaction between PA and NO2 on FPG levels was observed (Pfor interaction = 0.016). The interaction plots revealed that the beneficial effects of PA on FPG levels were attenuated or even reversed as NO2 concentrations increased, with a threshold for reversal at 33.02 µg/m3.

CONCLUSIONS

Long-term exposure to NO2 attenuates or reverses the beneficial effects of PA on FPG levels in non-diabetic older adults. Therefore, further action is imperative to reduce air pollution and thereby enhance the benefits of PA on FPG levels.

Impact of air pollution on depressive symptoms and the modifying role of physical activity: Evidence from the CHARLS study

The association between air pollution and depressive symptoms has not been thoroughly investigated, and the role of physical activity (PA) is particularly unclear. Although PA has been shown to alleviate depression, it may also increase exposure to air pollution, potentially exacerbating its adverse effects. A total of 17,332 participants aged 45 years and older from the 2018 wave of the China Health and Retirement Longitudinal Study (CHARLS) were included in this study to assess the causal effect of air pollution on depressive symptoms in China and to clarify the role of PA in this relationship. Depressive symptoms were assessed using the Center for Epidemiological Studies Depression Scale (CES-D). Data on particulate matter (PM1, PM2.5, and PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) were obtained from the ChinaHighAirPollutants (CHAP) dataset. PA levels were measured using a standardized questionnaire and categorized as low or high. An instrumental variable (IV) approach was used to estimate the causal effect of air pollution on depressive symptoms. Potential effect modification by PA was assessed. The IV estimates showed that all air pollutants were significantly and adversely associated with depressive symptoms, with a per interquartile range (IQR) increase in PM1, PM2.5, PM10, NO2, SO2, O3, and CO associated with 1.57 (95% confidence interval (CI): 1.15, 1.99), 1.49 (95% CI: 1.10, 1.89), 1.71 (95% CI: 1.26, 2.17), 2.22 (95% CI: 1.62, 2.81), 1.30 (95% CI: 0.96, 1.65), 4.67 (95% CI: 3.37, 5.98), and 0.97 (95% CI: 0.71, 1.22) units increase in CES-D scores, respectively. PA significantly modified this association, with higher PA levels mitigating the adverse effects of air pollution on depressive symptoms.

Exploring the Interplay Between Climate Change, 24-Hour Movement Behavior, and Health: A Systematic Review

BACKGROUND

Given the emergence of climate change and health risks, this review examined potential relationships between varying indicators of climate change, movement behaviors (ie, physical activity [PA], sedentary behavior, and sleep), and health.

METHODS

Seven databases were searched in March 2020, April 2023, and April 2024. To be included, studies must have examined indicators of climate change and at least one of the movement behaviors as either an exposure or a third variable (ie, mediator/moderator), and a measure of health as outcome. Evidence was summarized by the role (mediator/moderator) that either climate change or movement behavior(s) has with health measures. Relationships and directionality of each association, as well as the strength and certainty of evidence were synthesized.

RESULTS

A total of 79 studies were eligible, representing 6,671,791 participants and 3137 counties from 25 countries (40% low- and middle-income countries). Of 98 observations from 17 studies that examined PA as a mediator, 34.7% indicated that PA mediated the relationship between climate change and health measure such that indicators of adverse climate change were associated with lower PA, and worse health outcome. Of 274 observations made from 46 studies, 28% showed that PA favorably modified the negative association between climate change and health outcome. Evidence was largely lacking and inconclusive for sedentary behavior and sleep, as well as climate change indicators as an intermediatory variable.

CONCLUSIONS

PA may mitigate the adverse impact of climate change on health. Further evidence is needed to integrate PA into climate change mitigation, adaptation, and resilience strategies.

Outdoor Artificial Light at Night and Insomnia-Related Social Media Posts

Importance

Understanding the outcomes of artificial light at night (ALAN) on insomnia is crucial for public health, particularly in rapidly urbanizing regions. However, evidence of the association between ALAN exposure and insomnia is limited, despite the large number of people exposed to ALAN.

Objective

To explore the association between outdoor ALAN exposure and insomnia among the Chinese population.

Design, Setting, and Participants

This cross-sectional study used social media data from Weibo (Sina), a social media platform, and satellite-derived nighttime light images. The study period spans from May 2022 to April 2023. The study encompasses 336 cities across China's mainland, providing a comprehensive national perspective. Data include insomnia-related posts from the platform users, representing a large and diverse population sample exposed to varying levels of ALAN.

Exposure

Outdoor ALAN exposure (in nanowatts per centimeters squared per steradian [nW/cm2/sr]) was measured using satellite-derived nighttime light images at a spatial resolution of 500 m.

Main Outcomes and Measures

The incidence of insomnia among residents at the city level was measured by the number of insomnia-related posts on social media. Multiple linear regression models were used to estimate the association between ALAN exposure and population insomnia, adjusting for population characteristics and meteorological factors at the city level.

Results

The study included data from 1 147 583 insomnia-related posts. Daily mean ALAN exposure across the 336 cities ranged from 3.1 to 221.0 nW/cm2/sr. For each 5 nW/cm2/sr increase in ALAN exposure, the incidence of insomnia increased by 0.377% (95% CI, 0.372%-0.382%). The association was greater in less populated cities and under extreme temperature and poor air quality conditions. The observed exposure-response functions between ALAN exposure and insomnia demonstrated an upward trend, with steeper slopes observed at low exposures and leveling off at higher exposures.

Conclusions and Relevance

This study provides evidence of the association between increased ALAN exposure and higher incidence of insomnia. These findings expand the current knowledge on adverse health outcomes of ALAN exposure and emphasize the potential health benefits of well-planned artificial nighttime lighting in China and other developing countries in the early stages of city planning.

Long-term exposure to ozone and sleep disorders in children: A multicity study in China

Evidence regarding the link between long-term ambient ozone (O3) exposure and childhood sleep disorders is little. This study aims to examine the associations between long-term exposure to O3 and sleep disorders in children. We conducted a population-based cross-sectional survey, including 185,428 children aged 6-18 years in 173 schools across 14 Chinese cities during 2012 and 2018. Parents or guardians completed a checklist using Sleep Disturbance Scale for Children, and O3 exposure at residential and school addresses was estimated using a satellite-based spatiotemporal model. We used generalized linear mixed models to test the associations with adjustment for factors including socio-demographic variables, lifestyle, meteorology and multiple pollutants. Mean concentrations of O3, particulate matter with diameters ≤2.5 mm (PM2.5) and nitrogen dioxide (NO2) were 89.0 μg/m3, 42.5 μg/m3 and 34.4 μg/m3, respectively. O3 and NO2 concentrations were similar among provinces, while PM2.5 concentration varied significantly among provinces. Overall, 19.4% of children had at least one sleep disorder. Long-term exposure to O3 was positively associated with odds of sleep disorders for all subtypes. For example, each interquartile increment in home-school O3 concentrations was associated with a higher odds ratio for global sleep disorder, at 1.22 (95% confidence interval: 1.18, 1.26). Similar associations were observed for sleep disorder subtypes. The associations remained similar after adjustment for PM2.5 and NO2. Moreover, these associations were heterogeneous regionally, with more prominent associations among children residing in southeast region than in northeast and northwest regions in China. We concluded that long-term exposure to O3 is positively associated with risks of childhood sleep disorders. These associations varied by geographical region of China.

Physical activity attenuates the association of long-term exposure to nitrogen dioxide with sleep quality and its dimensions in Chinese rural older adults

BACKGROUND

Joint impacts of air pollution and physical activity (PA) on sleep quality remain unaddressed. We aimed to investigate whether PA attenuates the association of long-term exposure to nitrogen dioxide (NO2) with sleep quality and its dimensions in older adults.

METHODS

This study included 3408 Chinese rural older adults. Annual NO2 was estimated using the Space-Time Extra-Trees model. PA was assessed by International Physical Activity Questionnaire. Sleep quality was evaluated using Pittsburgh Sleep Quality Index (PSQI) scale. Linear regression models were used to assess the associations of long-term NO2 exposure and PA with sleep quality and its dimensions, and interaction plots were used to depict the attenuating effect of PA on associations of NO2 with sleep quality and its dimensions.

RESULTS

Three-year (3-y) average NO2 (per 0.64-μg/m3 increment) was positively associated with global PSQI (β = 0.41, 95 % CI: 0.23, 0.59), sleep duration (β = 0.16, 95 % CI: 0.11, 0.21), and habitual sleep efficiency (β = 0.22, 95 % CI: 0.17, 0.27), while PA was negatively associated with global PSQI (β = -0.33, 95 % CI: -0.46, -0.20) and five domains of PSQI other than sleep duration and sleep disturbances. The associations of NO2 with global PSQI, sleep duration, and habitual sleep efficiency were attenuated with increased PA (Pinteraction were 0.037, 0.020, and 0.079, respectively).

CONCLUSIONS

PA attenuates the adverse impacts of long-term NO2 exposure on sleep quality, especially on sleep duration, and habitual sleep efficiency, in Chinese rural elderly people. Participating in PA should be encouraged in this population, and continued efforts are still needed to reduce air pollution.

Associations of long-term exposure to air pollution and green space with reproductive hormones among women undergoing assisted reproductive technology: A longitudinal study

Studies investigating the association between long-term exposure to air pollution (AP)/green space and female reproductive hormones are still limited. Furthermore, their interactive effects remain unclear. Our study sought to explore the separate and interactive impacts of AP/green space on reproductive hormones among women undergoing assisted reproductive technology. We measured estradiol (E2), progesterone (P), testosterone (T), and follicle-stimulating hormone (FSH) from the longitudinal assisted reproduction cohort in Anhui, China. The annual mean concentrations of air pollutants were calculated at the residential level. Normalized Difference Vegetation Index (NDVI) within 500-m represented green space exposure. To assess the effect of AP/green space on hormones, we employed multivariable linear mixed-effect models. Our results showed that each one-interquartile range (IQR) increment in particulate matter (PM2.5 and PM10) and sulfur dioxide (SO2) was associated with -0.03[-0.05, -0.01], -0.03[-0.05, -0.02], and -0.03[-0.05, -0.01] decrease in P. An IQR increase in PM2.5, PM10, SO2, and carbon monoxide (CO) was associated with a -0.16[-0.17, -0.15], -0.15[-0.16, -0.14], -0.15[-0.16, -0.14], and -0.12[-0.13, -0.11] decrease in T and a -0.31[-0.35, -0.27], -0.30[-0.34, -0.26], -0.26[-0.30, -0.22], and -0.21[-0.25, -0.17] decrease in FSH. Conversely, NDVI500-m was associated with higher levels of P, T, and FSH, with β of 0.05[0.02, 0.08], 0.06[0.04, 0.08], and 0.07[0.00, 0.14]. Moreover, we observed the "U" or "J" exposure-response curves between PM2.5, PM10, and SO2 concentrations and E2 and P levels, as well as "inverted-J" curves between NDVI500-m and T and FSH levels. Furthermore, we found statistically significant interactions of SO2 and NDVI500-m on E2 and P as well as CO and NDVI500-m on E2. These findings indicated that green space might mitigate the negative effects of SO2 on E2 and P, as well as the effect of CO on E2. Future research is needed to determine these findings and underlying mechanisms.

Short-term ozone exposure and serum neural damage biomarkers in healthy elderly adults: Evidence from a panel study

BACKGROUND

Although converging lines of research have pointed to the adverse neural effects of air pollution, evidence linking ozone (O3) and neural damage remains limited.

OBJECTIVES

To investigate the subclinical neural effects of short-term ozone (O3) exposure in elderly adults.

METHODS

A panel of healthy elderly individuals was recruited, and five repeated measurements were conducted from December 2018 to April 2019 in Xinxiang, China. Serum neural damage biomarkers, including brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B) were measured at each follow-up session. Personal O3 exposure levels were calculated based on outdoor monitoring and sampling times. A linear mixed-effects model was adopted to quantify the acute effect of O3 on serum neural damage biomarkers. Stratification analysis based on sex, education level, physical activity, and glutathione S-transferases (GST) gene polymorphism analysis was performed to explore their potential modifying effects.

RESULTS

A total of 34 healthy volunteers aged 63.7 ± 5.7 y were enlisted and completed the study. The concentration of the daily maximum 8-h average O3 (O3-8h) ranged from 19.5 to 160.5 μg/m3 during the study period. Regression analysis showed that short-term O3 exposure was associated positively with serum concentrations of neural damage biomarkers. A 10 μg/m3 increase in O3-8h exposure was associated with an increment of 74 % (95 % CI:1 %-146 %) and 197 % (95 % CI:39 %-356 %) in BDNF (lag 2 d) and NfL (lag 1 d), respectively. The stratification results suggest that males, people with lower education levels, lower physical activity, and GST theta 1 (GSTT1)-sufficient genotype might be marginally more vulnerable.

CONCLUSIONS

This study provides new evidence for the neural damage risk posed by O3 exposure, even at relatively low concentrations, which, therefore, requires that stringent air quality standards be developed and implemented.

Exposure to polycyclic aromatic hydrocarbons increases the risk of poor sleep pattern in US adults: results from the NHANES (2005-2010)

Recently, polycyclic aromatic hydrocarbons (PAHs) were found to be linked to various diseases. The current study's objective was to explore whether or not there was a relation between PAH exposure and poor sleep pattern. We evaluated nine urine PAH metabolites as exposures in our cross-sectional research based on the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2010. Logistic regression, restricted cubic spline regression (RCS) model, weighted quantile sum (WQS) regression, subgroup analysis, and mediation analysis were used to assess the associations between PAH metabolism and poor sleep pattern risk. After controlling for all confounding variables, several primary PAH metabolites, namely 1-hydroxynapthalene (1-NAP, OR 1.32, 95% CI 1.04-1.68), 2-hydroxyfluorene (2-FLU, OR 1.34, 95% CI 1.05-1.71), 1-hydroxyphenanthrene (1-PHE, OR 1.30, 95% CI 1.03-1.64), 9-hydroxyfluorene (9-FLU, OR 1.38, 95% CI 1.09-1.74), and ∑PAHs (OR 1.33, 95% CI 1.05-1.69), compared to the bottom tertile, were associated with increased risk of poor sleep pattern. The WQS regression analysis showed that 9-FLU and 1-NAP comprised the two most important factors related to poor sleep pattern. Mediation analysis revealed that inflammation acted as a mediator between PAHs and the prevalence of poor sleep pattern. In conclusion, exposure to PAHs may be associated with poor sleep pattern. Inflammation is a mediator of the effects of PAH exposure on poor sleep pattern.

The association between polluted fuel use and self-reported insomnia symptoms among middle-aged and elderly Indian adults: a cross-sectional study based on LASI, wave 1

BACKGROUND

Insomnia predisposes the aging population to reduced quality of life and poor mental and physical health. Evidence of the association between polluted fuel use and insomnia symptoms is limited and is non-existent for the Indian population. Our study aimed to explore the link between polluted fuel use and insomnia symptoms in middle-aged and older (≥ 45 years) Indian populations.

METHODS

We utilized data from nationally representative Longitudinal Aging Study in India (LASI) Wave 1. Participants with complete information on fuel use, insomnia symptoms, and covariates were included. Insomnia symptoms were indicated by the presence of at least one of three symptoms: difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), or early morning awakening (EMA), ≥ 5 times/week. Survey-weighted multivariable logistic regression analyses were conducted to evaluate the association between polluted fuel use and insomnia symptoms. We also assessed the interaction of association in subgroups of age, gender, BMI, drinking, and smoking status.

RESULTS

Sixty thousand five hundred fifteen participants met the eligibility criteria. Twenty-eight thousand two hundred thirty-six (weighted percentage 48.04%) used polluted fuel and 5461 (weighted percentage 9.90%) reported insomnia symptoms. After full adjustment, polluted fuel use was associated with insomnia symptoms (OR 1.16; 95%CI 1.08-1.24) and was linked with DIS, DMS, and EMA (OR 1.14; 95%CI 1.05-1.24, OR 1.12; 95%CI 1.03-1.22, and OR 1.15; 95%CI 1.06-1.25, respectively). No significant interactions for polluted fuel use and insomnia symptoms were observed for analyses stratified by age, sex, BMI, drinking, or smoking.

CONCLUSIONS

Polluted fuel use was positively related to insomnia symptoms among middle-aged and older Indians. Suggestions are offered within this article for further studies to confirm our results, to explore underlying mechanisms, and to inform intervention strategies.

Exposures to ambient air pollutants increase prevalence of sleep disorder in adults: Evidence from Wuhan Chronic Disease Cohort Study (WCDCS)

BACKGROUND

Sleep disorder contributes to memory dysfunction and chronic diseases. Clear evidence of environment disturbance, such as residential noise, are associated with an increased risk of sleep disorder. However, not enough studies have been conducted on association between residential air pollutants and sleep disorder. We sought to determine whether exposures to residential air pollutants associated with risk of sleep disorder among adults.

METHODS

Using the dataset of the Wuhan Chronic Disease Cohort Study (WCDCS), we investigated the prevalence of sleep disorder and five sleep disorder symptoms in the study. The data of air pollutants (including PM10, PM2.5, NO2, SO2 and O3) were obtained from 10 air quality monitoring stations in Wuhan. We utilized logistic regression model to evaluate the associations of five types of air pollutants with odds ratio (OR) of sleep disorder and symptoms. The potential moderating effects of socio-demographic factors in the associations were explored using the interaction effects model.

RESULTS

Of the study participants, 52.1 % had sleep disorder. Exposures to higher concentrations of air pollutants were associated with increased prevalence of sleep disorder. For example, per interquartile range (IQR) increases in concentrations of PM10, PM2.5 or SO2 corresponded to the increase of sleep disorder increased prevalence at 14.7 % (adjusted odds ratio (aOR) = 1.147, 95 %CI:1.062, 1.240), 8.9 % (aOR = 1.089, 95 %CI: 1.003, 1.182) and 15.8 % (aOR = 1.158, 95 %CI: 1.065, 1.260). For symptoms specific analyses, significant linkages of PM10, PM2.5, SO2 with difficulty in falling asleep, wake up after falling asleep and early awaken were observed. Moderating effects of age and place of residence on the linkages of PM10 with increased prevalence of sleep disorder were identified.

CONCLUSION

Higher level of air pollution exposure could increase the prevalence of sleep disorder. Middle-aged and elderly population, as well as the rural residents are more likely to suffer from sleep disorder.

Air pollution attenuated the benefits of physical activity on blood pressure: Evidence from a nationwide cross-sectional study

INTRODUCTION

Although physical activity (PA) has multiple health benefits, the inhaled dose of fine particulate matter (PM2.5) during PA may increase. The trade-off between harmful effects of PM2.5 exposure and protective effects of PA remain unclear. Our study aims to examine the joint effects of PA and PM2.5 exposure on blood pressure (BP) in Chinese adults.

METHODS

A total of 203,108 adults aged ≥ 18 years from the China Hypertension Survey study (2012-2015) were included. Individual-level PA was assessed as minutes of metabolic equivalent tasks per week (MET-min/week). The average weekly PM2.5 exposures were estimated by using a spatial resolution of 10 km, integrating multiple data sources, including monitoring values, satellite measurements and model simulations. BP was measured with a professional portable BP monitor. Generalized linear regressions were used to estimate joint associations and to further explore two-dimensional nonlinear associations.

RESULTS

The median PA and 4-week PM2.5 average exposures were 3213.0 MET-min/week and 47.8 μg/m3, respectively. PA was negatively associated with BP, while PM2.5 exposure was positively with BP. The associations between PA and systolic BP were significantly modified by PM2.5 exposure (Pinteraction < 0.001). Compared with inactive participants under low PM2.5 exposure, those with highest level of PA under low PM2.5 exposure had a 0.90 (95 % CI: 0.53, 1.26) mmHg decrease in systolic BP, whereas they had a 0.48 (95 % CI: 0.07, 0.89) mmHg increase under high PM2.5 exposure. When PM2.5 exposure was approximately > 25 μg/m3, the joint exposure to total PA and PM2.5 was associated with an increase in systolic BP.

CONCLUSIONS

The benefits of PA on BP were counteracted by high PM2.5 levels.

Association between pregnancy termination history and metabolic syndrome in southwestern Chinese women: modification effect of physical activity

STUDY QUESTION

Is there a relationship between pregnancy termination history and metabolic syndrome (MetS), and if so, is the relationship moderated by physical activity (PA)?

SUMMARY ANSWER

Induced abortion, and both miscarriage and induced abortion, increased the risk of MetS, while leisure PA attenuated the effects of induced abortion, and both miscarriage and induced abortion, on the risk of MetS.

WHAT IS KNOWN ALREADY

Pregnancy termination history is a risk factor for cardiovascular disease, but studies on women's history of pregnancy termination and MetS are limited. PA is a preventive behavior for MetS, but its modification effect on any association between pregnancy termination history and MetS is unknown.

STUDY DESIGN, SIZE, DURATION

The cross-sectional study included 53 702 women (age range of 30-79 years old) from southwestern China who participated in the China Multi-Ethnic Cohort (CMEC) study from May 2018 to September 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants self-reported both the number and type of pregnancy termination. PA was assessed primarily by asking participants about the cumulative time they spent doing PA either as their occupation, transportation, housework, and leisure activity in the past year. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for all confounders, the risk of MetS was significantly increased in women who experienced induced abortion alone, and both miscarriage and induced abortion, with odds ratios (ORs) of 1.08 (95% CI = 1.03-1.13) and 1.20 (95% CI = 1.08-1.33), respectively. A dose-response relationship was observed between the number of induced abortions and MetS, with the risk increasing by 3.0% for every additional induced abortion (OR = 1.03, 95% CI = 1.01-1.05). Leisure PA had a significant modification effect on the relationship between pregnancy termination history and MetS, as leisure PA attenuates the negative effects of induced abortion on MetS.

LIMITATIONS, REASONS FOR CAUTION

Causality cannot be established in this study. Information on pregnancy termination and PA was collected by self-report, which might be subject to recall bias.

WIDER IMPLICATIONS OF THE FINDINGS

A history of induced abortion was associated with an increased risk of MetS, and the risk increased with the number of induced abortions. Leisure PA attenuated the negative effect of induced abortion on MetS, whereas occupational and transportation PA amplified the negative effect of induced abortion on glucose.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Key R&D Program of China (grant no.: 2017YFC0907300) and the National Nature Science Foundation of China (grant no.: 82273745). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Unexpected association between ambient ozone and adult insomnia outpatient visits: A large-scale hospital-based study

Growing evidence indicates that short-term ozone (O₃) exposure has substantial health consequences, but the relationship between short-term ambient O₃ and insomnia, a common sleep disorder, is not clear. This study aimed to investigate the short-term effects of ambient O₃ exposure on outpatient visits for adult insomnia and to explore the potential modifiers. A large-scale multihospital-based study was carried out in Chongqing, the largest city in Southwest China. Daily data on outpatient visits for adult insomnia, average concentrations of ambient air pollutants and meteorological factors were collected. We conducted quasi-Poisson regression with generalized additive model to assess the association between ambient O₃ and outpatient visits for adult insomnia in varied windows of exposure. Subgroup analyses were applied to identify its modifiers. Totally, 140,159 adult insomnia outpatient visits were identified. The daily maximum 8-h average concentration of O₃ was 69 μg/m³ during the study period, which greatly below the updated Chinese and WHO recommended limits (daily maximum 8-h average, O₃: 100 μg/m³). Short-term O₃ exposure was significantly negatively associated with outpatient visits for adult insomnia in different lag periods and the greatest decrease of outpatient visits for adult insomnia was found at lag 02 [0.93% (95% CI: 0.48%, 1.38%)]. Additionally, stronger links between O₃ and adult insomnia outpatient visits were presented in cool seasons, and we did not observe any significant modified effects of gender and age. Moreover, the negative O₃-insomnia association remained robust after controlling for other common air pollutants and comorbidities. In summary, short-term exposure to lower level of ambient O₃, was associated with reduced daily outpatient visits for adult insomnia and such association showed to be more obvious in cool seasons.

Does physical activity attenuate the association between ambient PM2.5 and physical function?

BACKGROUND

Physical function (PF), such as muscle strength, performing daily activities, has gradually declined with the increase of age, causing the occurrence of disability and diseases burden. Air pollution exposure and physical activity (PA) were both linked to PF. We aimed to explore the individual and joint effects of particulate matter <2.5 μm (PM2.5) and PA on PF.

METHODS

A total of 4537 participants and 12,011 observations aged ≥45 years old from the China Health and Retirement Longitudinal Study (CHARLS) cohort from 2011 to 2015 were included into the study. PF was assessed by a combined score of four tests, including grip strength, walking speed, sense of balance, and chair standing tests. Air pollution exposure data was from The ChinaHighAirPollutants (CHAP) dataset. The annual PM2.5 exposure for each individual was estimated based on county-level resident addresses. We estimated the volume of moderate-to-vigorous physical activity (MVPA) by quoting metabolic equivalent (MET). Multivariate linear model was conducted for baseline analysis, and linear mixed model with random participant intercepts was constructed for cohort longitudinal analysis.

RESULTS

PM2.5 was negatively associated with PF, while PA was positively associated with PF in baseline analysis. In cohort longitudinal analysis, a 10 μg/m3 increase in PM2.5 was associated to a 0.025 point (95 % CI: -0.047, -0.003) decrease in PF score, and a 10-MET-h/week increase in PA was related to a 0.004 point (95 % CI: 0.001, 0.008) increase in PF score. The association between PM2.5 and PF decreased by increased PA intensity, and PA reversed the detrimental effects between PM2.5 and PF.

CONCLUSION

PA attenuated the association of air pollution with PF at both high and low levels of air pollution, implying that PA may be an effective behavior to reduce the adverse effects of poor air quality on PF.

Long-term exposure to ambient air pollutants and their interaction with physical activity on insomnia: A prospective cohort study

Exposure to air pollution or lack of physical activity (PA) increases the risk of insomnia. However, evidence on joint exposure to air pollutants is limited, and the interaction of joint air pollutants and PA on insomnia is unknown. This prospective cohort study included 40,315 participants with related data from the UK Biobank, which recruited participants from 2006 to 2010. Insomnia was assessed by self-reported symptoms. The annual average air pollutant concentrations of particulate matter (PM_2.5, PM₁₀), nitrogen oxides (NO₂, NO_X), sulfur dioxide (SO₂) and carbon monoxide (CO) were calculated based on participants' addresses. We applied a weighted Cox regression model to evaluate the correlation between air pollutants and insomnia and newly proposed an air pollution score to assess joint air pollutants effect using a weighted concentration summation after obtaining the weights of each pollutant in the Weighted-quantile sum regression. With a median follow-up of 8.7 years, 8511 participants developed insomnia. For each 10 μg/m³ increase in NO₂, NO_X, PM₁₀, SO₂, the average hazard ratios (AHRs) and 95% confidence interval (CI) of insomnia were 1.10 (1.06, 1.14), 1.06 (1.04, 1.08), 1.35 (1.25, 1.45) and 2.58 (2.31, 2.89), respectively; For each 5 μg/m³ increase in PM_2.5 and each 1 mg/m³ increase in CO, the corresponding AHRs (95%CI) were 1.27 (1.21, 1.34) and 1.83 (1.10, 3.04), respectively. The AHR (95%CI) for insomnia associated with per interquartile range (IQR) increase in air pollution scores were 1.20 (1.15, 1.23). In addition, potential interactions were examined by setting cross-product terms of air pollution score with PA in the models. We observed an interaction between air pollution scores and PA (P = 0.032). The associations between joint air pollutants and insomnia were attenuated among participants with higher PA. Our study provides evidence on developing strategies for improving healthy sleep by promoting PA and reducing air pollution.

Effects of air pollution and residential greenness on sleep disorder: A 8-year nationwide cohort study

BACKGROUND

Sleep disorder influencing the quality of life, however, its contributing factors have not been fully identified yet. Recently the potential effects of environmental exposures like air pollution and greenness on sleep disorder have attracted attention, but the evidence in China is limited, particularly in the middle-aged and elderly.

METHODS

We conducted a nationwide prospective study that included 21,878 Chinese citizens aged 45 years or above. For each participant, the 3-year averaged exposure concentrations of air pollutants (including PM₁₀, PM_2.5, PM₁, NO₂) and greenness (assessed by NDVI) were estimated based on residential address. We used mixed-effects logistic models to examine the associations of sustained air pollutants and greenness exposures with the occurrence of sleep disorder, and used linear mixed-effects models to assess the associations with sleep duration. Specifically, interaction effects models were employed to identify potential modificators of the above associations.

RESULTS

A total of 39,580 survey responses were received, with the overall occurrence rate of sleep disorder was 25.7%. A 10 μg/m³ increment in PM₁₀ and PM_2.5 were associated with increased occurrence of sleep disorder at 2% (aOR = 1.02, 95%CI:1.01, 1.04) and 7% (aOR = 1.07, 95%CI: 1.04, 1.11), and were associated with reduced sleep duration by 0.07 (95% CI: 0.08, 0.05) and 0.04 (95% CI: 0.05, 0.03) hours, respectively. Residential greenness appears to the potential protective factor for sleep disorder, that a 0.1 higher of the NDVI was associated a 9% (aOR = 0.91, 95%CI: 0.86, 0.96) decreased occurrence of sleep disorder and 0.09 h (95% CI: 0.05, 0.13) longer of sleep duration. Age and residence were identified as modificators of the above significant associations.

CONCLUSION

Sustained exposure to air pollutants can increase the occurrence of sleep disorder and can reduce sleep duration, while exposure to higher levels of greenness can protect sleep health from the side effects of air pollutants.

Impacts of traffic-related particulate matter pollution on semen quality: A retrospective cohort study relying on the random forest model in a megacity of South China

BACKGROUND

Emerging evidence shows the detrimental impacts of particulate matter (PM) on poor semen quality. High-resolution estimates of PM concentrations are conducive to evaluating accurate associations between traffic-related PM exposure and semen quality.

METHODS

In this study, we firstly developed a random forest model incorporating meteorological factors, land-use information, traffic-related variables, and other spatiotemporal predictors to estimate daily traffic-related PM concentrations, including PM_2.5, PM₁₀, and PM₁. Then we enrolled 1310 semen donors corresponding to 4912 semen samples during the study period from January 1, 2019, and December 31, 2019 in Guangzhou city, China. Linear mixed models were employed to associate individual exposures to traffic-related PM during the entire (0-90 lag days) and key periods (0-37 and 34-77 lag days) with semen quality parameters, including sperm concentration, sperm count, progressive motility and total motility.

RESULTS

The results showed that decreased sperm concentration was associated with PM₁₀ exposures (β: -0.21, 95 % CI: -0.35, -0.07), sperm count was inversely related to both PM_2.5 (β: -0.19, 95 % CI: -0.35, -0.02) and PM₁₀ (β: -0.19, 95 % CI: -0.33, -0.05) during the 0-90 days lag exposure window. Besides, PM_2.5 and PM₁₀ might diminish sperm concentration by mainly affecting the late phase of sperm development (0-37 lag days). Stratified analyses suggested that PBF and drinking seemed to modify the associations between PM exposure and sperm motility. We did not observe any significant associations of PM₁ exposures with semen parameters.

CONCLUSION

Our results indicate that exposure to traffic-related PM_2.5 and PM₁₀ pollution throughout spermatogenesis may adversely affect semen quality, especially sperm concentration and count. The findings provided more evidence for the negative associations between traffic-related PM exposure and semen quality, highlighting the necessity to reduce ambient air pollution through environmental policy.

Associations and pathways between residential greenness and hyperuricemia among adults in rural and urban China

BACKGROUND

Residential greenness may decrease the risk for hyperuricemia in rural areas, but the urban-rural disparities in this association and underlying pathways have not been studied.

OBJECTIVES

To investigate the associations and potential pathways between residential greenness and hyperuricemia in urban and rural areas.

METHODS

The baseline survey of the China Multi-Ethnic Cohort (CMEC) was used. Hyperuricemia was defined as serum uric acid (SUA) > 417 μmol/L for men and >357 μmol/L for women. The satellite-based normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were used to capture residential greenness. A propensity score inverse-probability weighting method was used to assess urban-rural differences in the associations between residential greenness and hyperuricemia, with possible mediation effects of physical activity (PA), body mass index (BMI), PM_2.5, and NO₂ examined by causal mediation analyses.

RESULTS

A total of 72,372 participants were included. The increases in the EVI_500m and NDVI_500m residential greenness were associated with a decreased risk for hyperuricemia and the SUA level in both urban and rural areas. For example, each 0.1-unit increase in EVI_500m was associated with a decreased hyperuricemia risk of 7% (OR = 0.93 [0.91, 0.96]) and a decreased SUA level of -1.77 μmol/L [-2.60, -0.93], respectively; such associations were stronger in urban areas for both the risk for hyperuricemia (OR = 0.84 [0.83, 0.86]) and SUA level (-7.18 μmol/L [-7.91, -6.46]). The subgroup analysis showed that the greenness-hyperuricemia/SUA association varied by age, sex, and annual household income. The percentage of the joint mediation effect of PA, BMI, PM_2.5, and NO₂ on the association between EVI_500m and the risk for hyperuricemia was higher in urban (34.92%) than rural areas (15.40%). BMI, PM_2.5, and PA showed significantly independently mediation effects for the greenness-hyperuricemia association in both rural and urban areas.

CONCLUSIONS

Exposure to residential greenness was associated with a decreased risk for hyperuricemia, partially through the pathways of PA, BMI, PM_2.5, and NO₂, which varied in urban and rural areas.

Using an Exposome-Wide Approach to Explore the Impact of Urban Environments on Blood Pressure among Adults in Beijing-Tianjin-Hebei and Surrounding Areas of China

Existing studies mostly explored the association between urban environmental exposures and blood pressure (BP) in isolation, ignoring correlations across exposures. This study aimed to systematically evaluate the impact of a wide range of urban exposures on BP using an exposome-wide approach. A multicenter cross-sectional study was conducted in ten cities of China. For each enrolled participant, we estimated their urban exposures, including air pollution, built environment, surrounding natural space, and road traffic indicator. On the whole, this study comprised three statistical analysis steps, that is, single exposure analysis, multiple exposure analysis and a cluster analysis. We also used deletion-substitution-addition algorithm to conduct variable selection. After considering multiple exposures, for hypertension risk, most significant associations in single exposure model disappeared, with only neighborhood walkability remaining negatively statistically significant. Besides, it was observed that SBP (systolic BP) raised gradually with the increase in PM_2.5, but such rising pattern slowed down when PM_2.5 concentration reached a relatively high level. For surrounding natural spaces, significant protective associations between green and blue spaces with BP were found. This study also found that high population density and public transport accessibility have beneficially significant association with BP. Additionally, with the increase in the distance to the nearest major road, DBP (diastolic BP) decreased rapidly. When the distance was beyond around 200 m, however, there was no obvious change to DBP anymore. By cluster analysis, six clusters of urban exposures were identified. These findings reinforce the importance of improving urban design, which help promote healthy urban environments to optimize human BP health.

Effects of the COVID-19 Lockdown on Air Pollutant Levels and Associated Reductions in Ischemic Stroke Incidence in Shandong Province, China

Background

Local governments in China took restrictive measures after the outbreak of COVID-19 to control its spread, which unintentionally resulted in reduced anthropogenic emission sources of air pollutants. In this study, we intended to examine the effects of the COVID-19 lockdown policy on the concentration levels of particulate matter with aerodynamic diameters of ≤1 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), and carbon monoxide (CO) and the potential subsequent reductions in the incidence of ischemic and hemorrhagic stroke in Shandong Province, China.

Methods

A difference-in-difference model combining the daily incidence data for ischemic and hemorrhagic stroke and air pollutant data in 126 counties was used to estimate the effect of the COVID-19 lockdown on the air pollutant levels and ischemic and hemorrhagic stroke incident counts. The avoided ischemic stroke cases related to the changes in air pollutant exposure levels were further estimated using concentration-response functions from previous studies.

Results

The PM₁, PM_2.5, PM₁₀, NO₂, and CO levels significantly decreased by −30.2, −20.9, −13.5, −46.3, and −13.1%, respectively. The O₃ level increased by 11.5% during the lockdown compared with that in the counterfactual lockdown phase of the past 2 years. There was a significant reduction in population-weighted ischemic stroke cases (−15,315, 95% confidence interval [CI]: −27,689, −2,942), representing a reduction of 27.6% (95% CI: −49.9%, −5.3%). The change in the number of hemorrhagic stroke cases was not statistically significant. The total avoided PM₁-, PM_2.5-, PM₁₀-, NO₂-, and CO–related ischemic stroke cases were 739 (95% CI: 641, 833), 509 (95% CI: 440, 575), 355 (95% CI: 304, 405), 1,132 (95% CI: 1,024, 1,240), and 289 (95% CI: 236, 340), respectively.

Conclusion

The COVID-19 lockdown indirectly reduced the concentration levels of PM₁, PM_2.5, PM₁₀, NO₂, and CO and subsequently reduced the associated ischemic stroke incidence. The health benefits due to the lockdown are temporary, and long-term measures should be implemented to increase air quality and related health benefits in the post-COVID-19 period.

Smaller particular matter, larger risk of female lung cancer incidence? Evidence from 436 Chinese counties

BACKGROUND

Many studies have reported the effects of PM2.5 and PM10 on human health, however, it remains unclear whether particular matter with finer particle size has a greater effect.

OBJECTIVES

This work aims to examine the varying associations of the incidence rate of female lung cancer with PM1, PM2.5 and PM10 in 436 Chinese cancer registries between 2014 and 2016.

METHODS

The effects of PM1, PM2.5 and PM10 were estimated through three regression models, respectively. Mode l only included particular matter, while Model 2 and Model 3 further controlled for time and location factors, and socioeconomic covariates, respectively. Moreover, two sensitivity analyses were performed to investigate the robustness of three particular matte effects. Then, we examined the modifying role of urban-rural division on the effects of PM1, PM2.5 and PM10, respectively.

RESULTS

The change in the incidence rate of female lung cancer relative to its mean was 5.98% (95% CI: 3.40, 8.56%) for PM1, which was larger than the values of PM2.5 and PM10 at 3.75% (95% CI: 2.33, 5.17%) and 1.57% (95% CI: 0.73, 2.41%), respectively. The effects of three particular matters were not sensitive in the two sensitivity analyses. Moreover, urban-rural division positively modified the associations of the incidence rate of female lung cancer with PM1, PM2.5 and PM10.

CONCLUSIONS

The effect on the incidence rate of female lung cancer was greater for PM1, followed by PM2.5 and PM10. There were positive modifying roles of urban-rural division on the effects of three particular matters. The finding supports the argument that finer particular matters are more harmful to human health, and also highlights the great significance to develop guidelines for PM1 control and prevention in Chinese setting.

Requirements and Architecture of a Cloud Based Insomnia Therapy and Diagnosis Platform: A Smart Cities Approach

Insomnia is the most common sleep disorder worldwide. Its effects generate economic costs in the millions but could be effectively reduced using digitally provisioned cognitive behavioural therapy. However, traditional acquisition and maintenance of the necessary technical infrastructure requires high financial and personnel expenses. Sleep analysis is still mostly done in artificial settings in clinical environments. Nevertheless, innovative IT infrastructure, such as mHealth and cloud service solutions for home monitoring, are available and allow context-aware service provision following the Smart Cities paradigm. This paper aims to conceptualise a digital, cloud-based platform with context-aware data storage that supports diagnosis and therapy of non-organic insomnia. In a first step, requirements needed for a remote diagnosis, therapy, and monitoring system are identified. Then, the software architecture is drafted based on the above mentioned requirements. Lastly, an implementation concept of the software architecture is proposed through selecting and combining eleven cloud computing services. This paper shows how treatment and diagnosis of a common medical issue could be supported effectively and cost-efficiently by utilising state-of-the-art technology. The paper demonstrates the relevance of context-aware data collection and disease understanding as well as the requirements regarding health service provision in a Smart Cities context. In contrast to existing systems, we provide a cloud-based and requirement-driven reference architecture. The applied methodology can be used for the development, design, and evaluation of other remote and context-aware diagnosis and therapy systems. Considerations of additional aspects regarding cost, methods for data analytics as well as general data security and safety are discussed.