Acute effect of particulate matter pollution on hospital admissions for stroke among patients with type 2 diabetes in Beijing, China, from 2014 to 2018

Preexisting multimorbidity predicts greater mortality risks related to long-term PM2.5 exposure

Long-term health risk assessments related to ambient fine particulate matter (PM2.5) exposure have been more limited to general population but not towards individuals suffering from multimorbidity. While both multimorbidity and PM2.5 are independently linked to elevated mortality risk, their combined effects and interactions remain practically unexplored. A cross-cohort analysis was undertaken on data from 3 prospective cohorts, initially enrolling 869038 adults aged ≥18 years followed up during 2005-2022. Multimorbidity was identified at baseline surveys through a list of nine common chronic conditions. Cox proportional hazards models were utilized to quantify the associations of long-term PM2.5 exposure with all-cause, cardiovascular, and respiratory mortality among individuals with and without multimorbidity. Joint effects and interactions between baseline multimorbidity and PM2.5 level on the additive and multiplicative scales were examined. Risk differences of PM2.5-induced mortality were analyzed stratified by number of chronic conditions and multimorbidity patterns. Subgroup and sensitivity analyses were carried out to evaluate the consistency of the findings. Among 713119 eligible participants for primary analysis, 65490 prevalent cases of multimorbidity were identified at baseline over a median follow-up of 12.2 years. Compared to individuals without multimorbidity, associations of PM2.5 exposure with all-cause and cardiovascular mortality were more prominent among multimorbidity individuals (P <0.05 for heterogeneity). Our analysis unveiled a significant additive interaction between PM2.5 level and preexisting multimorbidity status, yielding estimated attributable proportions of 11.7%-17.8% and excess risks of 31.1%-72.6% for different mortality outcomes. Sex subgroup and sensitivity analyses consistently produced similar results. This large-scale multicohort analysis demonstrated markedly stronger associations between PM2.5 levels and risks of all-cause and cardiovascular mortality in multimorbidity populations compared to those without multimorbidity. PM2.5 exposure and preexisting multimorbidity showed synergistic effects in triggering mortality events, wherein the joint risks were intensified with elevated PM2.5 levels and an increased number of chronic conditions.

Ambient Air Pollution and Incident Cardiovascular Disease in People With Type 2 Diabetes Mellitus: A Cohort Study

OBJECTIVES

We aimed to assess the effect of air pollution on incident cardiovascular disease (CVD) in people with type 2 diabetes mellitus (T2DM).

METHODS

We tracked 486 T2DM patients from 2012 to 2021. Cox regression models were applied to assess the hazard of exposure to particulate matter, carbon monoxide (CO), ozone, nitrogen dioxide, and sulfur dioxide (SO 2 ) on incident CVD, revealing hazard ratios (HRs).

RESULTS

CVD incidents occurred in 73 individuals. Among men, each 1-ppm increase in CO levels raised the risk of CVD (HR: 2.66, 95% CI: 1.30-5.44). For women, a 5-ppb rise in SO 2 increased CVD risk (HR: 1.60, 95% CI: 1.11-2.30). No notable impact of particulate pollutants was found.

CONCLUSIONS

Persistent exposure to gaseous air pollutants, specifically CO and SO 2 , is linked to the development of CVD in men and women with T2DM.

Association between P M 10 and respiratory diseases admission in peninsula Malaysia during haze

Numerous studies have been conducted in other countries on the health effects of exposure to particulate matter with a diameter of 10 microns or less P M 10 , but little research has been conducted in Malaysia, particularly during the haze season. This study intends to investigate how exposure of P M 10 influenced hospital admissions for respiratory diseases during the haze period in peninsula Malaysia and it was further stratified by age group, gender and respiratory diseases categories. The study includes data from all patients with respiratory diseases in 92 government hospitals, as well as P M 10 concentration and meteorological data from 92 monitoring stations in Peninsula Malaysia starting from 1st January 2000 to 31st December 2019. A quasi-poison time series regression with distributed lag nonlinear model (DLNM) was employed in this study to examine the relationship between exposure of P M 10 and hospital admissions for respiratory diseases during the haze period. Haze period for this study has been defined from June to September each year. According to the findings of this study, P M 10 was positively associated with hospitalisation of respiratory disease within 30 lag days under various lag patterns, with lag 25 showing the strongest association (RR = 1.001742, CI 1.001029,1.002456). Using median as a reference, it was discovered that females were more likely than males to be hospitalized for P M 10 exposure. Working age group will be the most affected by the increase in P M 10 exposure with a significant cumulative RR from lag 010 to lag 030. The study found that P M 10 had a significant influence on respiratory hospitalisation in peninsula Malaysia, particularly for lung diseases caused by external agents(CD5). Therefore, it is important to implement effective intervention measures to control P M 10 and reduce the burden of respiratory disease admissions.

Short-Term Exposure to Air Pollution and the Incidence and Mortality of Stroke: A Meta-Analysis

BACKGROUND

The relationship between short-term exposure to various air pollutants [particulate matter <10 μm (PM 10 ), particulate matter <2.5 μm (PM 2.5 ), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), carbon monoxide, and ozone (O 3 )] and the incidence and mortality of stroke remain unclear.

REVIEW SUMMARY

We conducted a comprehensive search across databases, including PubMed, Web of Science, and others. A random-effects model was employed to estimate the odds ratios (OR) and their 95% CIs. Short-term exposure to PM 10 , PM 2.5 , NO 2 , SO 2 , and O 3 was associated with increased stroke incidence [per 10 μg/m 3 increase in PM 2.5 : OR = 1.005 (95% CI: 1.004-1.007), per 10 μg/m 3 increase in PM 10 : OR = 1.006 (95% CI: 1.004-1.009), per 10 μg/m 3 increase in SO 2 : OR = 1.034 (95% CI: 1.020-1.048), per 10 μg/m 3 increase in NO 2 : OR = 1.029 (95% CI: 1.015-1.043), and O 3 for per 10 μg/m 3 increase: OR: 1.006 (95% CI: 1.004-1.007)]. In addition, short-term exposure to PM 2.5 , PM 10 , SO 2, and NO 2 was correlated with increased mortality from stroke [per 10 μg/m 3 increase in PM 2.5 : OR = 1.010 (95% CI: 1.006-1.013), per 10 μg/m 3 increase in PM 10 : OR = 1.004 (95% CI: 1.003-1.006), per 10 μg/m 3 increase in SO 2 : OR = 1.013 (95% CI: 1.007-1.019) and per 10 μg/m 3 increase in NO 2 : OR = 1.012 (95% CI: 1.008-1.015)].

CONCLUSION

Reducing outdoor air pollutant levels may yield a favorable outcome in reducing the incidence and mortality associated with strokes.

The Short-Term Effects and Burden of Ambient Air Pollution on Hospitalization for Type 2 Diabetes: Time-Stratified Case-Crossover Evidence From Sichuan, China

Type 2 diabetes mellitus (T2DM), a complicated metabolic disease, might be developed or exacerbated by air pollution, resulting in economic and health burden to patients. So far, limited studies have estimated associations between short-term exposure to air pollution and disease burden of T2DM in China. Hence, we aimed to estimate the associations and burden of ambient air pollutants (NO2, PM10, PM2.5, SO2, and CO) on hospital admissions (HAs) for T2DM using a time-stratified case-crossover design. Data on HAs for T2DM during 2017-2019 were collected from hospital electronic health records in nine cities in Sichuan Province using conditional poisson regression. Totally, 92,381 T2DM hospitalizations were recorded. There were significant short-term effects of NO2, PM10, PM2.5, SO2 and CO on HAs for T2DM. A 10 μg/m3 increment of NO2, PM10, PM2.5, SO2 and CO as linked with a 3.39% (95% CI: 2.26%, 4.54%), 0.33% (95% CI: 0.04%, 0.62%), 0.76% (95% CI: 0.35%, 1.16%), 12.68% (95% CI: 8.14%, 17.42%) and 79.00% (95% CI: 39.81%, 129.18%) increase in HAs for T2DM at lag 6. Stratified analyses modified by age, sex, and season showed old (≥65 years) and female patients linked with higher impacts. Using WHO's air quality guidelines of NO2, PM10, PM2.5, and CO as the reference, the attributable number of T2DM HAs exceeding these pollutants exposures were 786, 323, 793, and 2,127 during 2017-2019. Besides, the total medical costs of 25.83, 10.54, 30.74, and 67.78 million China Yuan were attributed to NO2, PM10, PM2.5, and CO. In conclusion, short-term exposures to air pollutants were associated with higher risks of HAs for T2DM.

Short-Term Effects of Carbon Monoxide on Morbidity of Chronic Obstructive Pulmonary Disease With Comorbidities in Beijing

The association between CO and chronic obstructive pulmonary disease (COPD) has been widely reported; however, the association among patients with type 2 diabetes mellitus (T2DM) or hypertension has remained largely unknown in China. Over-dispersed generalized additive model was adopted to quantity the associations between CO and COPD with T2DM or hypertension. Based on principal diagnosis, COPD cases were identified according to the International Classification of Diseases (J44), and a history of T2DM and hypertension was coded as E12 and I10-15, O10-15, P29, respectively. A total of 459,258 COPD cases were recorded from 2014 to 2019. Each interquartile range uptick in CO at lag 03 corresponded to 0.21% (95%CI: 0.08%-0.34%), 0.39% (95%CI: 0.13%-0.65%), 0.29% (95%CI: 0.13%-0.45%) and 0.27% (95%CI: 0.12%-0.43%) increment in admissions for COPD, COPD with T2DM, COPD with hypertension and COPD with both T2DM and hypertension, respectively. The effects of CO on COPD with T2DM (Z = 0.77, P = 0.444), COPD with hypertension (Z = 0.19, P = 0.234) and COPD with T2DM and hypertension (Z = 0.61, P = 0.543) were insignificantly higher than that on COPD. Stratification analysis showed that females were more vulnerable than males except for T2DM group (COPD: Z = 3.49, P < 0.001; COPD with T2DM: Z = 0.176, P = 0.079; COPD with hypertension: Z = 2.48, P = 0.013; COPD with both T2DM and hypertension: Z = 2.44, P = 0.014); No statistically significant difference could be found between age groups (COPD: Z = 1.63, P = 0.104; COPD with T2DM: Z = 0.23, P = 0.821; COPD with hypertension: Z = 0.53, P = 0.595; COPD with both T2DM and hypertension: Z = 0.71, P = 0.476); Higher effects appeared in cold seasons than warm seasons on COPD (Z = 0.320, P < 0.001). This study demonstrated an increased risk of COPD with comorbidities related to CO exposure in Beijing. We further provided important information on lag patterns, susceptible subgroups, and sensitive seasons, as well as the characteristics of the exposure-response curves.

Exposure to air pollution and its effect on ischemic strokes (EP-PARTICLES study)

It is well known that exceeded levels of particulate matter in the air and other air pollutants harmfully affect the cardiovascular system. Empirical analyses of the effects of these factors on stroke incidence and mortality are still limited. The main objective of our analyses was to determine the association between short-term exposure to air pollutants and stroke incidence in non-industrial areas, more specifically in north-eastern Poland. To achieve this aim, we used data from the National Health Fund on patients hospitalized for stroke between 2011 and 2020 in the largest city of the region described as the Green Lungs of Poland. The pollution levels and atmospheric conditions data were obtained from the Provincial Inspectorate for Environmental Protection and the Institute of Meteorology and Water Management. Using daily data on hospitalizations, atmospheric conditions, and pollution, as well as ordered logistic regression models the hypotheses on the impact of weather and air pollution conditions on ischemic strokes were tested. The study group included 4838 patients, 45.6% of whom were male; the average patient age was approximately 74 years. The average concentrations of PM_2.5 were 19.09 µg/m³, PM₁₀ 26.66 µg/m³ and CO 0.35 µg/m³. Analyses showed that an increase in PM_2.5 and PM₁₀ concentrations by 10 µg/m³ was associated with an increase in the incidence of stroke on the day of exposure (OR = 1.075, 95% CI 0.999-1.157, P = 0.053; OR = 1.056, 95% CI 1.004-1.110, P = 0.035) and the effect was even several times greater on the occurrence of a stroke event in general (PM_2.5: OR = 1.120, 95% CI 1.013-1.237, P = 0.026; PM₁₀: OR = 1.103, 95% CI 1.028-1.182, P = 0.006). Furthermore, a short-term (up to 3 days) effect of CO on stroke incidence was observed in the study area. An increase of 1 μg/m³ CO was associated with a lower incidence of stroke 2 days after the exposure (OR = 0.976, 95% CI 0.953-0.998, P = 0.037) and a higher incidence 3 days after the exposure (OR = 1.026, 95% CI 1.004-1.049, P = 0.022).

The underlying mechanism of PM2.5-induced ischemic stroke

Under the background of global industrialization, PM_2.5 has become the fourth-leading risk factor for ischemic stroke worldwide, according to the 2019 GBD estimates. This highlights the hazards of PM_2.5 for ischemic stroke, but unfortunately, PM_2.5 has not received the attention that matches its harmfulness. This article is the first to systematically describe the molecular biological mechanism of PM_2.5-induced ischemic stroke, and also propose potential therapeutic and intervention strategies. We highlight the effect of PM_2.5 on traditional cerebrovascular risk factors (hypertension, hyperglycemia, dyslipidemia, atrial fibrillation), which were easily overlooked in previous studies. Additionally, the effects of PM_2.5 on platelet parameters, megakaryocytes activation, platelet methylation, and PM_2.5-induced oxidative stress, local RAS activation, and miRNA alterations in endothelial cells have also been described. Finally, PM_2.5-induced ischemic brain pathological injury and microglia-dominated neuroinflammation are discussed. Our ultimate goal is to raise the public awareness of the harm of PM_2.5 to ischemic stroke, and to provide a certain level of health guidance for stroke-susceptible populations, as well as point out some interesting ideas and directions for future clinical and basic research.

Association between ambient air pollution and hospital admissions, length of hospital stay and hospital cost for patients with cardiovascular diseases and comorbid diabetes mellitus: Base on 1,969,755 cases in Beijing, China, 2014-2019

BACKGROUND

Evidence on the effects of the air pollutants on the hospital admissions, hospital cost and length of stay (LOS) among patients with comorbidities remains limited in China, particularly for patients with cardiovascular diseases and comorbid diabetes mellitus (CVD-DM).

METHODS

We collected daily data on CVD-DM patients from 242 hospitals in Beijing between 2014 and 2019. Generalized additive model was employed to quantify the associations between admissions, LOS, and hospital cost for CVD-DM patients and air pollutants. We further evaluated the attributable risk posed by air pollutants to CVD-DM patients, using both Chinese and WHO air quality guidelines as reference.

RESULTS

Per 10 ug/m³ increase of particles with an aerodynamic diameter < 2.5 μm (PM_2.5), particles with an aerodynamic diameter < 10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbonic oxide (CO) and ozone (O₃) corresponded to a 0.64% (95% CI: 0.57 to 0.71), 0.52% (95% CI: 0.46 to 0.57), 0.93% (95% CI: 0.67 to 1.20), 0.98% (95% CI: 0.81 to 1.16), 1.66% (95% CI: 1.18 to 2.14) and 0.53% (95% CI: 0.45 to 0.61) increment for CVD-DM patients' admissions. Among the six pollutants, particulate pollutants (PM_2.5 and PM₁₀) in most lag days exhibited adverse effects on LOS and hospital cost. For every 10 ug/m³ increase in PM_2.5 and PM₁₀, the absolute increase with LOS will increase 62.08 days (95% CI: 28.93 to 95.23) and 51.77 days (95% CI:22.88 to 80.66), respectively. The absolute increase with hospital cost will increase 105.04 Chinese Yuan (CNY) (95% CI: 49.27 to 160.81) and 81.76 CNY (95% CI: 42.01 to 121.51) in PM_2.5 and PM₁₀, respectively. Given WHO 2021 air quality guideline as the reference, PM_2.5 had the maximum attributable fraction of 3.34% (95% CI: 2.94% to 3.75%), corresponding to an avoidable of 65,845 (95% CI: 57,953 to 73,812) patients with CVD-DM.

CONCLUSION

PM_2.5 and PM₁₀ are positively associated with hospital admissions, hospital cost and LOS for patients with CVD-DM. Policy changes to reduce air pollutants exposure may reduce CVD-DM admissions and substantial savings in health care spending and LOS.

Ambient Air Pollution and Risk for Stroke Hospitalization: Impact on Susceptible Groups

Stroke is a leading cause of death, and air pollution is associated with stroke hospitalization. However, the susceptibility factors are unclear. Retrospective studies from 2014 to 2018 in Kaohsiung, Taiwan, were analyzed. Adult patients (>17 years) admitted to a medical center with stroke diagnosis were enrolled and patient characteristics and comorbidities were recorded. Air pollutant measurements, including those of particulate matter (PM) with aerodynamic diameters < 10 μm (PM10) and < 2.5 μm (PM2.5), nitrogen dioxide (NO2), and ozone (O3), were collected from air quality monitoring stations. During the study period, interquartile range (IQR) increments in PM2.5 on lag3 and lag4 were 12.3% (95% CI, 1.1−24.7%) and 11.5% (95% CI, 0.3−23.9%) concerning the risk of stroke hospitalization, respectively. Subgroup analysis revealed that the risk of stroke hospitalization after exposure to PM2.5 was greater for those with advanced age (≥80 years, interaction p = 0.045) and hypertension (interaction p = 0.034), after adjusting for temperature and humidity. A dose-dependent effect of PM2.5 on stroke hospitalization was evident. This is one of few studies focusing on the health effects of PM2.5 for patients with risk factors of stroke. We found that patients with risk factors, such as advanced age and hypertension, are more susceptible to PM2.5 impacts on stroke hospitalization.

Acute effect of air pollutants' peak-hour concentrations on ischemic stroke hospital admissions among hypertension patients in Beijing, China, from 2014 to 2018

Air pollutants' effect on ischemic stroke (IS) has been widely reported. But the effect of high-level concentrations during people's outdoor periods among hypertension patients was unknown. Peak-hour concentrations were defined considering air pollutants' high concentrations as well as people's outdoor periods. We conducted a time-series study and used the generalized additive model to analyze peak-hour concentrations' acute effect. A total of 315,499 IS patients comorbid with hypertension were admitted to secondary and above hospitals in Beijing from 2014 to 2018. A 10 µg/m³ (CO: 1 mg/m³) increase of the peak-hour concentrations was positively associated with IS hospital admissions among hypertension patients. The maximum effect sizes were as follows: for PM_2.5, 0.17% (95% confidence interval [CI]: 0.10-0.24%) at Lag0 and 0.22% (95% CI: 0.12-0.33%) at Lag0-5; for PM₁₀, 0.09% (95% CI: 0.05-0.13%) at Lag5 and 0.17% (95% CI: 0.09-0.26%) at Lag0-5; for SO₂, 0.87% (95% CI: 0.46-1.29%) at Lag5; for NO₂, 0.83% (95% CI: 0.62-1.04%) at Lag0 and 0.86% (95% CI: 0.59-1.13%) at Lag0-1; for CO 1.23% (95% CI: 0.66-1.80%) at Lag0 and 1.33% (95% CI: 0.33-2.35%) at Lag0-5; for O₃ 0.23% (95% CI: 0.12-0.35%) at Lag0 and 0.20% (95% CI: 0.05-0.34%) at Lag0-1. The effect sizes of PM_2.5, NO₂, and O₃ remained significant after adjusting daily mean. Larger effect sizes were observed for PM_2.5 and PM₁₀ in cool season and for O₃ in warm season. As significant exposure indicators of air pollution, peak-hour concentrations exposure increased the risk of IS hospital admissions among hypertension patients and it is worthy of consideration in relative environmental standard. It is suggested for hypertension patients to avoid outdoor activity during peak hours. More relevant searches are required to further illustrate air pollutant's effect on chronic disease population.

The association between ozone and ischemic stroke morbidity among patients with type 2 diabetes in Beijing, China

BACKGROUND

The association between ozone and ischemic stroke has been widely reported; however, the association among patients with type 2 diabetes (T2D) has remained largely unknown.

METHODS

The time series data of daily morbidity and concentrations of ozone from 2014 to 2018 were collected in Beijing, China. A time-stratified case-crossover study combined with a distributed lag nonlinear model was used to estimate the ozone effect on stroke morbidity among T2D patients. Based on principal diagnosis, ischemic stroke cases were identified according to the International Classification of Diseases (I63), and a history of T2D was coded as E12.

RESULTS

A total of 149,757 hospital admissions for ischemic stroke among T2D patients were recorded in Beijing. Approximately U-shaped exposure-response curves were observed for ozone and ischemic stroke morbidity among T2D patients. With a reference at 54.91 μg/m³, extreme-low (5th: 9.59 μg/m³) ozone was significantly associated with a decreased risk for ischemic stroke [RR = 0.88, 95% confidence interval (CI): 0.80-0.98]. Subgroup analysis showed that extremely low-ozone (5th) level only had a significant protective effect in males and elderly population, with a RR value of 0.86 (95% CI: 0.76-0.97) and 0.85 (95% CI: 0.75-0.96), respectively. Extreme-high ozone (99th: 157.06 μg/m³) was significantly associated with an increased risk for ischemic stroke (RR = 1.33, 95% CI: 1.12-1.57). The effect size was 1.34 (95% CI: 1.10-1.63) for males and 1.32 (95% CI: 1.07-1.63) for females, and the difference was not significant (Z = -0.29, P = 0.77). The effect size in younger adults was significantly higher than that in participants aged ≥65 years [1.52 (95% CI: 1.21-1.91) vs. 1.22 (95% CI: 1.01-1.47), Z = -1.62, P < 0.05].

CONCLUSIONS

U-shaped associations were observed between ozone and ischemic stroke morbidity in T2D patients. Men and elderly population are vulnerable to low-ozone level, and the younger adults are more susceptible to extremely high-ozone level than the elderly.

Associations between serum PFOA and PFOS levels and incident chronic kidney disease risk in patients with type 2 diabetes

Chronic kidney disease (CKD) is a common comorbidity among patients with type 2 diabetes. Exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) has been linked to poorer kidney function in general population, but the related studies in individuals with diabetes were very limited. We aimed to examine the longitudinal associations of PFOA and PFOS exposure and CKD incidence among diabetes patients. Baseline levels of PFOA and PFOS were measured in serum in 967 diabetes patients from the Dongfeng-Tongji cohort. Multivariable logistic regression models were used to characterize the relationship between serum PFOA and PFOS levels and incident CKD risk (defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²). During 10-years follow-up, 267 incident CKD cases were identified. Only PFOS level was significantly associated with lower risk of CKD incidence (adjusted OR: 0.67; 95%CI: 0.51, 0.88). Such inverse association was only observed among participants with lower eGFR levels (< 70 mL/min/1.73 m²), although the interaction did not achieve statistical significance. Notably, an inverted U-shaped relationship between eGFR and serum PFOS level (P_{for nonlinearity} < 0.001) was observed based on the 1825 subjects with available data at baseline. PFOS exposure was negatively associated with CKD incidence in patients with diabetes, especially in those with baseline eGFR levels < 70 mL/min/1.73 m². This may be explained by the implication of baseline kidney function on the serum PFAS concentrations which in turn affect the relationship between PFOS exposure and the incident CKD risk among diabetes.

Acute effect of particulate matter pollution on hospital admissions for cause-specific respiratory diseases among patients with and without type 2 diabetes in Beijing, China, from 2014 to 2020

BACKGROUND

Scientific studies have identified various adverse effects of particulate matter (PM) on respiratory disease (RD) and type 2 diabetes (T2D). However, whether short-term exposure to PM triggers the onset of RD with T2D, compared with RD without T2D, has not been elucidated.

METHODS

A two-stage time-series study was conducted to evaluate the acute adverse effects of PM on admission for RD and for RD with and without T2D in Beijing, China, from 2014 to 2020. District-specific effects of PM_2.5 and PM₁₀ were estimated using the over-dispersed Poisson generalized addictive model after adjusting for weather conditions, day of the week, and long-term and seasonal trends. Meta-analyses were applied to pool the overall effects on overall and cause-specific RD, while the exposure-response (E-R) curves were evaluated using a cubic regression spline.

RESULTS

A total of 1550,154 admission records for RD were retrieved during the study period. Meta-analysis suggested that per interquartile range upticks in the concentration of PM_2.5 corresponded to 1.91% (95% CI: 1.33-2.49%), 2.16% (95% CI: 1.08-3.25%), and 1.92% (95% CI: 1.46-2.39%) increments in admission for RD, RD with T2D, and RD without T2D, respectively, at lag 0-8 days, lag 8 days, and lag 8 days. The effect size of PM_2.5 was statistically significantly higher in the T2D group than in the group without T2D (z = 3.98, P < 0.01). The effect sizes of PM₁₀ were 3.86% (95% CI: 2.48-5.27%), 3.73% (95% CI: 1.72-5.79%), and 3.92% (95% CI: 2.65-5.21%), respectively, at lag 0-13 days, lag 13 days, and lag 13 days, respectively, and no statistically significant difference was observed between T2D groups (z = 0.24, P = 0.81). Significant difference was not observed between T2D groups for the associations of PM and different RD and could be found between three groups for effects of PM₁₀ on RD without T2D. The E-R curves varied by sex, age and T2D condition subgroups for the associations between PM and daily RD admissions.

CONCLUSIONS

Short-term PM exposure was associated with increased RD admission with and without T2D, and the effect size of PM_2.5 was higher in patients with T2D than those without T2D.