Effects of ambient particulate matter on fasting blood glucose among primary school children in Guangzhou, China

Associations of insulin sensitivity and immune inflammatory responses with child blood lead (Pb) and PM2.5 exposure at an e-waste recycling area during the COVID-19 lockdown

Fine particular matter (PM2.5) and lead (Pb) exposure can induce insulin resistance, elevating the likelihood of diabetes onset. Nonetheless, the underlying mechanism remains ambiguous. Consequently, we assessed the association of PM2.5 and Pb exposure with insulin resistance and inflammation biomarkers in children. A total of 235 children aged 3-7 years in a kindergarten in e-waste recycling areas were enrolled before and during the Corona Virus Disease 2019 (COVID-19) lockdown. Daily PM2.5 data was collected and used to calculate the individual PM2.5 daily exposure dose (DED-PM2.5). Concentrations of whole blood Pb, fasting blood glucose, serum insulin, and high mobility group box 1 (HMGB1) in serum were measured. Compared with that before COVID-19, the COVID-19 lockdown group had lower DED-PM2.5 and blood Pb, higher serum HMGB1, and lower blood glucose and homeostasis model assessment of insulin resistance (HOMA-IR) index. Decreased DED-PM2.5 and blood Pb levels were linked to decreased levels of fasting blood glucose and increased serum HMGB1 in all children. Increased serum HMGB1 levels were linked to reduced levels of blood glucose and HOMA-IR. Due to the implementation of COVID-19 prevention and control measures, e-waste dismantling activities and exposure levels of PM2.5 and Pb declined, which probably reduced the association of PM2.5 and Pb on insulin sensitivity and diabetes risk, but a high level of risk of chronic low-grade inflammation remained. Our findings add new evidence for the associations among PM2.5 and Pb exposure, systemic inflammation and insulin resistance, which could be a possible explanation for diabetes related to environmental exposure.

Effect of short-term exposure to air pollution on hospital admission for cardiovascular disease: A time-series study in Xiangyang, China

BACKGROUND

Data on the relationship between short-term exposure to air pollution and cardiovascular diseases (CVDs) and the potential modifying factors are limited and inconsistent.

OBJECTIVE

To explore the relationship between short-term exposure to air pollution and CVD risk, and potential modification effect factors.

METHOD

A time series study was conducted on 52,991 hospital admissions for CVD from 2015 to 2019 in Xiangyang City, China. Air pollution data from four national fixed monitoring stations were collected to estimate exposure level in Xiangyang City. A quasi-Poisson generalized additive model incorporating a distributed lag nonlinear model was applied to evaluate the association between air pollution and CVD risk. The potential modification effect of sex, age, and season on the above associations was also evaluated.

RESULTS

CVD risk was positively associated with air pollution. Peak associations in single lag day structures were observed for particulate matter ≤10 μm in aerodynamic (PM10; RR: 1.040, 95 % CI: 0.996-1.087), PM2.5 (1.025, 1.004-1.045), nitrogen dioxide (NO2; 1.074, 1.039-1.111), and sulfur dioxide (SO2; 1.079, 1.019-1.141) at Lag 0 and ozone (O3; 1.018, 1.004-1.031) at Lag 4. In cumulative lag day structures, the highest RRs were 1.225 (1.079,1.392) for PM10 at Lag 06, 1.054 (1.013, 1.098) for PM2.5 at Lag 03, 1.200 (1.119, 1.287) for NO2 at Lag 04, and 1.135 (1.025, 1.257) for SO2 at Lag 02. Moreover, the association between air pollution and CVD risk was modified by sex and age (P < 0.05). Females and individuals aged ≤65 years were more vulnerable to NO2 and had a higher CVD risk.

CONCLUSION

Short-term exposure to air pollution was positively associated with CVD risk. Moreover, sex and age could modify the effect of air pollution on CVD risk. Females and individuals aged ≤65 years had a higher NO2 exposure-induced CVD risk.

The Association Between PM2.5 Exposure and Diabetes Mellitus Among Thai Army Personnel

OBJECTIVES

This study investigated the association between baseline exposures to particulate matter with a diameter < 2.5 microns (PM2.5) and subsequent temporal changes in PM2.5 exposure with the incidence of type 2 diabetes among Royal Thai Army personnel.

METHODS

A retrospective cohort study was conducted using nationwide health check-up data from 21 325 Thai Army personnel between 2018 and 2021. Multilevel mixed-effects parametric survival statistics were utilized to analyze the relationship between baseline (i.e., PM2.5-baseline) and subsequent changes (i.e., PM2.5-change) in PM2.5 exposure and the occurrence of type 2 diabetes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were employed to assess this association while considering covariates.

RESULTS

There was a significant association between both PM2.5 baseline and PM2.5-change and the incidence of type 2 diabetes in a dose-response manner. Compared to quartile 1, the HRs for quartiles 2 to 4 of PM2.5-baseline were 1.11 (95% CI, 0.74 to 1.65), 1.51 (95% CI, 1.00 to 2.28), and 1.77 (95% CI, 1.07 to 2.93), respectively. Similarly, the HRs for quartiles 2 to 4 of PM2.5-change were 1.41 (95% CI, 1.14 to 1.75), 1.43 (95% CI, 1.13 to 1.81) and 2.40 (95% CI, 1.84 to 3.14), respectively.

CONCLUSIONS

Our findings contribute to existing evidence regarding the association between short-term and long-term exposure to PM2.5 and the incidence of diabetes among personnel in the Royal Thai Army.

Effects of PM2.5 and high-fat diet interaction on blood glucose metabolism in adolescent male Wistar rats: A serum metabolomics analysis based on ultra-high performance liquid chromatography/mass spectrometry

Fine particulate matter (PM_2.5) and high-fat diet (HFD) are known to contribute to blood glucose metabolic disorders. However, limited research has investigated the combined impact of PM_2.5 and HFD on blood glucose metabolism. This study aimed to explore the joint effects of PM_2.5 and HFD on blood glucose metabolism in rats using serum metabolomics and to identify involved metabolites and metabolic pathways. The 32 male Wistar rats were exposed to filtered air (FA) or PM_2.5 (real-world inhaled, concentrated PM_2.5, 8 times the ambient level, ranging from 131.42 to 773.44 μg/m³) and fed normal diet (ND) or HFD for 8 weeks. The rats were divided into four groups (n = 8/group): ND-FA, ND-PM_2.5, HFD-FA and HFD-PM_2.5 groups. Blood samples were collected to determine fasting glucose (FBG), plasma insulin and glucose tolerance test and HOMA Insulin Resistance (HOMA-IR) index was calculated. Finally, the serum metabolism of rats was analyzed by ultra-high performance liquid chromatography/mass spectrometry (UHPLC-MS). Then we constructed the partial least squares discriminant analysis (PLS-DA) model to screen the differential metabolites, and performed pathway analysis to screen the main metabolic pathways. Results showed that combined effect of PM_2.5 and HFD caused changes in glucose tolerance, increased FBG levels and HOMA-IR in rats and there were interactions between PM_2.5 and HFD in FBG and insulin. By metabonomic analysis, the serum differential metabolites pregnenolone and progesterone, which involved in steroid hormone biosynthesis, were two different metabolites in the ND groups. In the HFD groups, the serum differential metabolites were L-tyrosine and phosphorylcholine, which involved in glycerophospholipid metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. When PM_2.5 and HFD coexist, they may lead to more severe and complex effects on glucose metabolism by affecting lipid metabolism and amino acid metabolism. Therefore, reducing PM_2.5 exposure and controlling dietary structure are important measures for preventing and reducing glucose metabolism disorders.

Air Pollution, Built Environment, and Early Cardiovascular Disease

As the world's population becomes increasingly urbanized, there is growing concern about the impact of urban environments on cardiovascular health. Urban residents are exposed to a variety of adverse environmental exposures throughout their lives, including air pollution, built environment, and lack of green space, which may contribute to the development of early cardiovascular disease and related risk factors. While epidemiological studies have examined the role of a few environmental factors with early cardiovascular disease, the relationship with the broader environment remains poorly defined. In this article, we provide a brief overview of studies that have examined the impact of the environment including the built physical environment, discuss current challenges in the field, and suggest potential directions for future research. Additionally, we highlight the clinical implications of these findings and propose multilevel interventions to promote cardiovascular health among children and young adults.

Sustained air pollution exposures, fasting plasma glucose, glycated haemoglobin, prevalence and incidence of diabetes: a nationwide study in China

BACKGROUND

Evidence remains limited and inconsistent for the associations between sustained air pollution exposures and diabetes development. This study aimed to determine the potential effects of particulate matter with a diameter of ≤10 micrometres (PM10), particulate matter with a diameter of ≤2.5 micrometres (PM2.5) and nitrogen dioxide (NO2) on alterations of fasting plasma glucose (FPG), glycated haemoglobin (HbA1c), in particular, on prevalence and incidence of diabetes.

METHODS

Cross-sectional analyses were conducted based on 9628 participants aged ≥45 years from the baseline survey (2011) of the China Health and Retirement Longitudinal Study (CHARLS), whereas cohort analyses were based on 3510 individuals without diabetes at baseline in the third survey (2015). Residences of participants were geocoded and the air pollution exposures were estimated using a satellite-based spatiotemporal model. Linear, logistic and modified Poisson regression models, adjusting for multiple confounders, were applied to assess the associations between air pollution and FPG, HbA1c, prevalence and incidence of diabetes, respectively.

RESULTS

Associations between PM10, PM2.5 and increased levels of FPG and HbA1c were identified. The levels of FPG and HbA1c increased by 0.025 mmol/L (95% CI: 0.007, 0.044) and 0.011 mmol/L (95% CI: 0.002, 0.019), respectively, for a 10-μg/m3 increase in PM10, and the levels of FPG and HbA1c increased by 0.061 mmol/L (95% CI: 0.028, 0.096) and 0.016 mmol/L (95% CI: 0.000, 0.031), respectively, for a 10-μg/m3 increase in PM2.5. There were also positive associations between diabetes prevalence and PM2.5 and PM10. In the cohort analyses, PM10, PM2.5 and NO2 were associated with a higher incidence of diabetes.

CONCLUSION

Air pollution was allied to diabetes development in elderly Chinese populations. Considering the impact of the dramatic increase in the incidence and prevalence of diabetes in China, interventions to improve air quality are urgently needed.

Effects of long-term PM2.5 exposure on metabolic syndrome among adults and elderly in Guangdong, China

BACKGROUND

We aimed to explore the association between long-term exposure to particulate matter ≤ 2.5 µm (PM_2.5) and metabolic syndrome (MetS) and its components including fasting blood glucose (FBG), blood pressure, triglyceride (TG), high-density lipoprotein cholesterol (HDL-c) and waist circumference among adults and elderly in south China.

METHODS

We surveyed 6628 participants in the chronic disease and risk factors surveillance conducted in 14 districts of Guangdong province in 2015. MetS was defined based on the recommendation by the Joint Interim Societies' criteria. We used the spatiotemporal land-use regression (LUR) model to estimate the two-year average exposure of ambient air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, and O₃) at individual levels. We recorded other covariates by using a structured questionnaire. Generalized linear mixed model was used for analysis.

RESULTS

A 10-μg/m³ increase in the two-year mean PM_2.5 exposure was associated with a higher risk of developing MetS [odd ratio (OR): 1.17, 95% confidence interval (CI): 1.01, 1.35], increased risk of fasting blood glucose level. (OR: 1.18, 95% CI: 1.02, 1.36), and hypertriglyceridemia (OR: 1.36, 95% CI: 1.18, 1.58) in the adjusted/unadjusted models (all P < 0.05). We found significant interaction between PM_2.5 and the region, exercise on the high TG levels, and an interaction with the region, age, exercise and grain consumption on FBG (P _interaction < 0.05).

CONCLUSIONS

Long-term exposure to PM_2.5 was associated with MetS, dyslipidemia and FBG impairment. Efforts should be made for environment improvement to reduce the burden of MetS-associated non-communicable disease.

Linking the Fasting Blood Glucose Level to Short-Term-Exposed Particulate Constituents and Pollution Sources: Results from a Multicenter Cross-Sectional Study in China

Ambient PM_2.5 (fine particulate matter with aerodynamic diameters ≤ 2.5 μm) is thought to be associated with the development of diabetes, but few studies traced the effects of PM_2.5 components and pollution sources on the change in the fasting blood glucose (FBG). In the present study, we assessed the associations of PM_2.5 constituents and their sources with the FBG in a general Chinese population aged over 40 years. Exposure to PM_2.5 was positively associated with the FBG level, and each interquartile range (IQR) increase in a lag period of 30 days (18.4 μg/m³) showed the strongest association with an elevated FBG of 0.16 mmol/L (95% confidence interval: 0.04, 0.28). Among various constituents, increases in exposed elemental carbon, organic matter, arsenic, and heavy metals such as silver, cadmium, lead, and zinc were associated with higher FBG, whereas barium and chromium were associated with lower FBG levels. The elevated FBG level was closely associated with the PM_2.5 from coal combustion, industrial sources, and vehicle emissions, while the association with secondary sources was statistically insignificant. Improving air quality by tracing back to the pollution sources would help to develop well-directed policies to protect human health.

The neonatal PROC gene rs1799809 polymorphism modifies the association between prenatal air pollutants exposure and PROC promoter methylation

Prenatal air pollution, protein C (PROC) gene abnormal methylation, and genetic mutation can cause a series of neonatal diseases, but the complex relationship between them remains unclear. Here, we recruited 552 mothers and their own babies during January 2010-January 2012 in Zhengzhou to explore such association. The air pollutant data was obtained from the Environmental Monitoring Stations. The rs1799809 genotype and the methylation levels at the promoter region of PROC in genomic DNA samples were detected respectively by TaqMan probe and quantitative methylation specific PCR using real-time PCR system. The results show that the levels of neonatal PROC methylation were negatively associated with concentrations of NO₂ during the entire pregnancy, particularly during the third trimester. Of particular significance, only in newborns carrying rs1799809 AA genotype, negatively significant associations between PROC methylation levels and exposure concentrations of air pollutants were observed. Further, we observed a significant interactive effect between neonatal rs1799809 genotype and SO₂ exposure during the entire pregnancy on neonatal PROC methylation levels. Prenatal exposure to ambient air pollutants specifically was associated with the neonatal PROC promoter methylation level of newborns carrying the rs1799809 AA genotype. Taken together, these findings suggest that neonatal PROC methylation levels are associated with prenatal exposure to ambient air pollutants, and this association can be modified by rs1799809 genotype.

Impact of polluting fuels for cooking on diabetes mellitus and glucose metabolism in south urban China

We hypothesized that exposure to polluting fuels for cooking was associated with abnormality of glucose metabolism and diabetes mellitus (DM) in south urban China. 3414 residents were surveyed in 14 urban areas of Guangdong Province in 2018. We recorded polluting fuels for cooking exposure, different DM status (DM, prediabetes), fasting blood glucose (FBG), oral glucose tolerance test (OGTT), glycated hemoglobin (HbA_1c ), and other covariates by using a structured questionnaire. We conducted logistic regression model and multivariate linear regression model based on propensity-score method (inverse probability of weighting) to examine the effect of polluting fuels for cooking exposure on DM and glucose metabolism. Exposure to polluting fuels for cooking was associated with DM (odds ratio: 2.57, 95% confidence interval: 1.71 to 3.86) and prediabetes (odds ratio: 1.98, 95% confidence interval: 1.52 to 2.58) in both the adjusted and unadjusted models (all p < 0.05). Exposure to polluting fuels for cooking was significantly associated with an increase of FBG (β: 0.30 mmol/L, 95% confidence interval: 0.22 to 0.38 mmol/L). Sensitivity analysis showed that the results were not substantially changed. There was an increased risk of DM, prediabetes and high levels of FBG, OGTT, and HbA_1c among participants aged ≥ 40 years with exposure to polluting fuels for cooking. We demonstrated that exposure to polluting fuels for cooking was associated with higher levels of FBG, which contributed to the increased risk of DM and prediabetes in middle-aged elderly Chinese population living in urban areas.

Cardiovascular Effects of Particulate Air Pollution

Inhalation of fine particulate matter (PM_2.5), produced by the combustion of fossil fuels, is an important risk factor for cardiovascular disease. Exposure to PM_2.5 has been linked to increases in blood pressure, thrombosis, and insulin resistance. It also induces vascular injury and accelerates atherogenesis. Results from animal models corroborate epidemiological evidence and suggest that the cardiovascular effects of PM_2.5 may be attributable, in part, to oxidative stress, inflammation, and the activation of the autonomic nervous system. Although the underlying mechanisms remain unclear, there is robust evidence that long-term exposure to PM_2.5 is associated with premature mortality due to heart failure, stoke, and ischemic heart disease. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Exposure to biomass fuel is associated with high blood pressure and fasting blood glucose impairment in females in southern rural China

OBJECTIVES

We sought to investigate the association between household exposure to biomass fuel and metabolic syndrome (MetS) and its components including blood pressure, triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG) and waist circumference among females in southern rural China.

METHODS

We surveyed 1664 residents in the Chronic Disease and Risk Factors Surveillance, conducted in 14 districts of Guangdong province. We recorded the use of biomass fuel, MetS and its components, and other covariates by using a structured questionnaire. Logistic regression model and multivariate linear regression model were adopted for analysis.

RESULTS

Exposure to biomass fuel was significantly associated with an increase of systolic blood pressure (SBP) (β: 2.15, 95% confidence interval: 0.13 to 4.17) and FBG (β: 0.19, 95% confidence interval: 0.01 to 0.37) in the adjusted and unadjusted models (all P < 0.05). Among participants with exposure to biomass fuel, being overweight or obese was associated with an increased risk of having hypertension (odds ratio: 3.19, 95% confidence interval: 2.13 to 4.76) and higher FBG levels (odds ratio: 2.10, 95% confidence interval: 1.46 to 3.02). Exposure to biomass fuel was significantly associated with a decrease of the prevalence of central obesity (P < 0.05). However, exposure to biomass fuel was not associated with MetS, diastolic blood pressure and TG (all P > 0.05).

CONCLUSIONS

Exposure to biomass fuel is associated with an increase in blood pressure and FBG levels, but not MetS per se. Efforts should be made to protect females in southern rural China from the adverse effects associated with biomass fuel pollution.

Air pollution-associated blood pressure may be modified by diet among children in Guangzhou, China

OBJECTIVES

To assess the associations between long-term air pollution exposure and blood pressure in children, and to explore the modifying effects of diet on prehypertension and hypertension.

METHODS

We evaluated 7225 primary school children aged 6-12 years from Guangzhou, China, in 2017. The blood pressure was measured objectively. The individual 1-year average concentration of particles with an aerodynamic diameter of 2.5 μm or less or 10 μm or less (PM2.5, PM10), sulfur dioxide (SO2), and ozone (O3) before each blood pressure measurement were calculated by inverse distance weighting interpolation according to each home address. Generalized linear mixed-effects models were used to examine the health effects and potential effect modifications by diet factors after adjusting for covariates.

RESULTS

The results showed that the estimated increase in mean SBP was 0.92 mmHg (95% CI 0.05-1.79) per interquartile range increase in O3. An interquartile range increase in the 1-year mean of SO2 and O3 was associated with odds ratios of 1.26 (95% CI 1.04-1.52) and 1.20 (95% CI 1.06-1.35) for prehypertension, respectively. In addition, an interquartile range increase in PM2.5, SO2, and O3 exposure was positively associated with hypertension, with odds ratios of 1.33 (95% CI 1.11-1.61), 1.70 (95% CI 1.33-2.16), and 1.48 (95% CI 1.20-1.83), respectively. Stronger effect estimates between PM2.5, SO2, and O3 concentration on prehypertension were exhibited among subgroups of children with a higher intake of sugar-sweetened beverages.

CONCLUSION

Long-term exposure to PM2.5, SO2, and O3 were associated with higher blood pressure levels in children, and dietary intake might modify these associations.

Long-term exposure to ambient air pollution and metabolic syndrome in children and adolescents: A national cross-sectional study in China

BACKGROUND

The prevalence of metabolic syndrome (MetS) rapidly increased over the past decades. However, little evidence exists about the effects of long-term exposure to ambient air pollution on MetS in children and adolescents.

OBJECTIVE

This study aims to assess the association between long-term ambient air pollution and the prevalence of MetS in a large population of Chinese children and adolescents.

METHODS

In 2013, a total of 9,897 children and adolescents aged 10 to 18 years were recruited from seven provinces/municipalities in China. MetS was defined based on the recommendation by the International Diabetes Federation (IDF). Satellite based spatio-temporal models were used to estimate exposure to ambient air pollution (including particles with diameters ≤1.0 µm (PM₁), ≤2.5 µm (PM_2.5), and ≤10 µm (PM₁₀), and nitrogen dioxide (NO₂)). Individual exposure was calculated according to 94 schools addresses. After adjustment for a range of covariates, generalized linear mixed-effects models were utilized to evaluate the associations between air pollutants and the prevalence of MetS and its components. In addition, several stratified analyses were examined according to sex, weight status, outdoor physical activity time, and sugar-sweetened beverages (SSBs) intake.

RESULTS

The prevalence of MetS was 2.8%. The odds ratio of MetS associated with a 10 μg/m³ increase in PM₁, PM_2.5, PM₁₀ and NO₂ was 1.20 (95%CI: 0.99, 1.46), 1.31 (95%CI: 1.05, 1.64), 1.32 (95%CI: 1.08, 1.62), and 1.33 (95%CI: 1.03, 1.72), respectively. Regarding the MetS components, we observed associations between all pollutants and abdominal obesity. In addition, long-term PM₁ and NO₂ exposures were associated with the prevalence of elevated fasting blood glucose. Stratified analyses detected that the associations between air pollutants and the prevalence of MetS were stronger in boys (P_interaction < 0.05).

CONCLUSIONS

We found that long-term exposure to PM_2.5, PM₁₀, and NO₂ were positively associated with the prevalence of MetS in children and adolescents. Our findings may have certain public health implications for some comprehensive strategy of environment improvement and lifestyles changes in order to reduce the burden of non-communicable disease.

Elevated environmental PM2.5 increases risk of schizophrenia relapse: Mediation of inflammatory cytokines

BACKGROUND

Ecological epidemiology suggests that hospital admissions for schizophrenia are associated with an increased environmental PM_2.5, but no prospective study has verified this result, and the physiological mechanism is not clear.

METHODS

We used a repeated-measures design to prospectively assess the association of environmental PM_2.5 and the risk of relapse in schizophrenia, and used two linear mixed-effects models to explore possible mediating effects of immune cytokines on the premise of controlling confounders.

RESULTS

We import the data using EpiData software, and collate and analyze of the data using R software. The increase of PM_2.5 at lag0 had the greatest impact on the relapse of schizophrenia (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.504, that is to say, odds ratio (OR) = 4.500 (95% confidence interval (CI): 2.849-7.106，P < 0.001)), and cumulative effects lasted for four days with the maximum at the second day (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.301, OR = 3.673 (95%CI: 1.962-6.876，P < 0.001)). PM_2.5 exposure was statistically related to four symptom dimensions of early signs scale (ESS), and the symptoms most affected by the increased PM_2.5 were depression/withdrawal (ESSN) (OR = 1.990, 95%CI: 1.701-2.328), anxiety/agitation (ESS-A) (OR = 1.537, 95%CI: 1.340-1.763), initial psychosis (ESS-IP) (OR = 1.398, 95%CI: 1.151-1.697), and disinhibition (ESS-D) (OR = 1.235, 95%CI: 1.133-1.347). Furthermore, there are three statistically significant pathways in intermediary analysis: of PM_2.5 and relapse risk: "PM_2.5 → IL-17 → ESS", "PM_2.5 → IL-17 → ESS-A", and "PM_2.5 → IL-17 → ESS-N", and the intermediary ratio of IL-17 was 11.66%, 16.37% and 22.55%, respectively.

CONCLUSIONS

Increased environmental PM_2.5 is a risk factor for the relapse of schizophrenia. Early relapse identification and intervention based on clinical characteristics are of great significance for timely termination of relapse and slowing down of relapse.

Inflammatory effects of particulate matter air pollution

Air pollution is an important cause of non-communicable diseases globally with particulate matter (PM) as one of the main air pollutants. PM is composed of microscopic particles that contain a mixture of chemicals and biological elements that can be harmful to human health. The aerodynamic diameter of PM facilitates their deposition when inhaled. For instance, coarse PM having a diameter of < 10 μm is deposited mainly in the large conducting airways, but PM of < 2.5 μm can cross the alveolar-capillary barrier, traveling to other organs within the body. Epidemiological studies have shown the association between PM exposure and risk of disease, namely those of the respiratory system such as lung cancer, asthma, and chronic obstructive pulmonary disease (COPD). However, cardiovascular and neurological diseases have also been reported, including hypertension, atherosclerosis, acute myocardial infarction, stroke, loss of cognitive function, anxiety, and Parkinson's and Alzheimer's diseases. Inflammation is a common hallmark in the pathogenesis of many of these diseases associated with exposure to a variety of air pollutants, including PM. This review focuses on the main effects of PM on human health, with an emphasis on the role of inflammation.

Association between ambient particulate matter (PM10) and incidence of diabetes in northwest of China: A prospective cohort study

OBJECTIVES

We aimed to assess the association between long-term exposure to ambient PM₁₀ and risk of diabetes incidence, based on the "Jinchang Cohort" platform in the Northwest of China.

METHODS

We selected 19884 subjects who had not yet developed diabetes in the baseline and had completed survey information from "Jinchang Cohort". The residential address was used to match the nearest pollution monitoring station for each subject, and the average concentration of PM₁₀ from baseline to follow-up were used as an estimate of individual exposure level. Cox regression model and restricted cubic splines functions were used to evaluate the effects of PM₁₀ on the incidence of diabetes and the dose-response relationship after adjusting for confounding covariates.

RESULTS

We observed 791 new-onset diabetics with a total follow-up of 45254.16 person-years (incidence rate of 17.48 per 1000 person-years). The risk of diabetes incidence increased by 17% (HR = 1.17, 95%CI: 1.08-1.26) per 10μg/m³ increase in environmental PM₁₀, and the risk rises gradually with the rise of PM₁₀ concentration. Comparing with the first quartile of PM₁₀, the fully adjusted HRs (95%CI) for incident diabetes from the second to the fourth quartile of PM₁₀ were 1.15 (95%CI: 0.93-1.43), 1.50 (95%CI: 1.22-1.84) and 1.44 (95%CI: 1.15-1.79), respectively (P for trend<0.001). Stratified analyses suggested that the risk of diabetes incidence associated with ambient PM₁₀ was higher in female, young to middle-aged people, overweight and obese subjects, and subjects with FPG level at baseline lower than 5.6 mmol/L.

CONCLUSIONS

Long-term exposure to ambient PM₁₀ significantly associated with a higher risk of diabetes development. Some urgent strategies may be advocated to reduce air pollution that can aid in preventing the prevalence of diabetes in the population.

The relationship between long-term exposure to PM2.5 and fasting plasma glucose levels in Chinese children and adolescents aged 6-17 years: A national cross-sectional study

BACKGROUND

Previous studies investigating the association between PM_2.5 exposure and fasting plasma glucose levels (FPGLs) are mostly limited to short- and mid-term PM_2.5 exposure and lack adjustments for key confounders in adult research.

OBJECTIVES

Exploring the relationship between seven years long-term PM_2.5 exposure and FPGLs in Chinese children and adolescents aged 6-17 years.

METHODS

Between September 2013 and December 2013, 16,489 participants aged 6-17 years were recruited using a four-staged, stratified, cluster sampling strategy from 7 provinces, autonomous regions and municipalities of mainland China. A generalized linear mixed model (GLMM) was used to estimate the relationship between annual PM_2.5 exposure (2007-2013) and FPGLs stratified by sex and one-year age increments. Sociodemographic characteristics, living with both parents, early-life factors, behaviours, and infection symptoms were gradually adjusted from the crude model to regression model 6, and BMI was adjusted for in model 7.

RESULTS

The annual concentration of PM_2.5 was 56.23 (±12.99) μg/m³. The mean FPGLs in the 8551 boys (4.75 mmol/L ± 0.52) was significantly higher than that in the 8194 girls (4.63 mmol/L ± 0.48) (P < 0.0001). In model 6, for every 10 μg/m3 increase in PM_2.5 exposure, the FPGLs in boys and girls increased by 0.048 (95% CIs 0.031 to 0.065) mmol/L (P < 0.0001) and 0.054 (95% CIs 0.039 to 0.069) mmol/L (P < 0.0001), respectively. The FPGLs were significantly positively associated with long-term PM_2.5 exposure at the ages of 12, 15 and 16 years in both the boys and girls and exhibited age differences in model 7. The prevalence of impaired fasting plasma glucose (IFP) and diabetes decreased by 0.8% when the exposure concentration of PM_2.5 was reduced by 10 μg/m³ in model 6, which assessed the negative effects of PM_2.5 exposure and revealed that 1,298,920 children and adolescents could have been protected from IFP and diabetes in 2013 in China.

CONCLUSIONS

Long-term PM_2.5 exposure may be an independent risk factor of elevated FPGLs. The adverse effect of PM_2.5 exposure on FPGLs in children and adolescents could appear after 10 years of cumulative exposure. The precise intervention time was revealed as approximately 12 and 11 years in boys and girls, respectively. There are great public health implications associated with early prevention strategies for the eradication of the negative effects of long-term exposure to PM_2.5 on FPGLs.

Cumulative Lifetime Burden of Cardiovascular Disease From Early Exposure to Air Pollution

The disease burden associated with air pollution continues to grow. The World Health Organization (WHO) estimates ≈7 million people worldwide die yearly from exposure to polluted air, half of which-3.3 million-are attributable to cardiovascular disease (CVD), greater than from major modifiable CVD risks including smoking, hypertension, hyperlipidemia, and diabetes mellitus. This serious and growing health threat is attributed to increasing urbanization of the world's populations with consequent exposure to polluted air. Especially vulnerable are the elderly, patients with pre-existing CVD, and children. The cumulative lifetime burden in children is particularly of concern because their rapidly developing cardiopulmonary systems are more susceptible to damage and they spend more time outdoors and therefore inhale more pollutants. World Health Organization estimates that 93% of the world's children aged <15 years-1.8 billion children-breathe air that puts their health and development at risk. Here, we present growing scientific evidence, including from our own group, that chronic exposure to air pollution early in life is directly linked to development of major CVD risks, including obesity, hypertension, and metabolic disorders. In this review, we surveyed the literature for current knowledge of how pollution exposure early in life adversely impacts cardiovascular phenotypes, and lay the foundation for early intervention and other strategies that can help prevent this damage. We also discuss the need for better guidelines and additional research to validate exposure metrics and interventions that will ultimately help healthcare providers reduce the growing burden of CVD from pollution.

Long-term exposure to PM2.5 and fasting plasma glucose in non-diabetic adolescents in Yogyakarta, Indonesia

BACKGROUND

Indonesia is facing serious air pollution. However, very few studies have been conducted to examine the health risks of air pollution in Indonesia, particularly for adolescents.

OBJECTIVE

To assess the association between long-term exposure to ambient particles with a diameter of <2.5 μm (PM_2.5) and fasting plasma glucose (FPG) in adolescents.

METHODS

A cross-sectional study was conducted in 482 adolescents aged 14-18 years in Yogyakarta, Indonesia in 2016. We finally included 469 (97.30%) participants who had no missing data for data analysis. We collected individual data on socio-demographics, behavioral habits, and health information through standardized questionnaires. Satellite-based PM_2.5 concentrations from 2013 to 2016 were assigned based on participants' residential addresses. The association between PM_2.5 and FPG was examined using a generalized linear regression model while FPG was modeled as a continuous variable. An ordered logistic regression model was used to assess the relationship between PM_2.5 and FPG categories.

RESULTS

Every 1 μg/m³ increase in PM_2.5 was associated with a 0.34 mg/dL [95 confidence interval (95% CI): 0.08 mg/dL, 0.59 mg/dL] increase in FPG levels. Comparing with the low FPG level (under 86 mg/dL), every 1 μg/m³ increase in PM_2.5 was associated with a 10.20% (95% CI: 1.60%, 19.80%) increase in the odds of impaired fasting glucose (IFG) (100-125 mg/dL). Stratified analyses indicated greater effects on participants with hypertension [odds ratio (OR) = 1.30, 95% CI: 1.09, 1.57] and those had higher physical activities (OR = 1.36, 95% CI: 1.09, 1.57). Adolescents' sex, obesity status and different cutoff points of FPG did not modify the association between the exposure to PM_2.5 and FPG levels.

CONCLUSION

Long-term exposure to PM_2.5 was associated with increased FPG levels in Indonesian non-diabetic adolescents.