Emergency Department Visits for Asthma Exacerbation due to Weather Conditions and Air Pollution in Chuncheon, Korea: A Case-Crossover Analysis

Effects of climate change on patients with respiratory and cardiovascular conditions

Climate change is one of the most significant global challenges and is already having detrimental effects on people's health. Pollution levels and ambient temperatures continue to increase, resulting in higher levels of humidity and pollen production. These environmental threats can affect many vulnerable patients, particularly those with respiratory and cardiovascular conditions, and nurses have a crucial role in raising awareness of the health implications of climate change. This article explores the pathophysiological effects of climate change on patients with asthma, chronic obstructive pulmonary disease and cardiovascular disease, and aims to enhance nurses' understanding of the health challenges of climate change.

Asthma triggered by extreme temperatures: From epidemiological evidence to biological plausibility

BACKGROUND

There is rapidly growing evidence indicating that extreme temperature is a crucial trigger and potential activator of asthma; however, the effects of extreme temperature on asthma are inconsistently reported and the its potential mechanisms remain undefined.

OBJECTIVES

This review aims to estimate the impacts of extreme heat, extreme cold, and temperature variations on asthma by systematically summarizing the existing studies from epidemiological evidence to biological plausibility.

METHODS

We conducted a systematic search in PubMed, Embase, and Web of Science from inception to June 30, 2022, and we retrieved articles of epidemiology and biological studies which assessed associations between extreme temperatures and asthma. This protocol was registered with PROSPERO (CRD42021273613).

RESULTS

From 12,435 identified records, 111 eligible studies were included in the qualitative synthesis, and 37 articles were included in the meta-analysis (20 for extreme heat, 16 for extreme cold, and 15 for temperature variations). For epidemiological evidence, we found that the synergistic effects of extreme temperatures, indoor/outdoor environments, and individual vulnerabilities are important triggers for asthma attacks, especially when there is extreme heat or cold. Meta-analysis further confirmed the associations, and the pooled relative risks for asthma attacks in extreme heat and extreme cold were 1.07 (95%CI: 1.03-1.12) and 1.20 (95%CI: 1.12-1.29), respectively. Additionally, this review discussed the potential inflammatory mechanisms behind the associations between extreme temperatures and asthma exacerbation, and highlighted the regulatory role of immunological pathways and transient receptor potential ion channels in asthma triggered by extreme temperatures.

CONCLUSIONS

We concluded that both extreme heat and cold could significantly increase the risk of asthma. Additionally, we proposed a potential mechanistic framework, which is important for understanding the disease pathogenesis that uncovers the complex mechanisms of asthma triggered by extreme temperatures and protects the sensitive individuals from impacts of extreme weather events and climate change.

Patterns of medical care utilization according to environmental factors in asthma and chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use.

RESULTS

The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males.

CONCLUSION

Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.

Relationship between biometeorological factors and the number of hospitalizations due to asthma

The incidence of asthma exacerbation depends on atmospheric conditions, including such meteorological factors as the ambient temperature, relative air humidity or concentration of atmospheric aerosols. An assessment of relations between the frequency of asthma exacerbation and environmental conditions was made according to the meteorological components, the biometeorological index UTCI (Universal Thermal Climate Index), as well as selected air quality parameters, including concentrations of PM₁₀ and PM_2.5. The study was conducted on the basis of a retrospective analysis of medical data collected at the Independent Public Hospital of Tuberculosis and Pulmonary Diseases in Olsztyn (Poland). Our analysis of patient data (from 1 January 2013 until 31 December 2017) showed a significant correlation between the number of asthma exacerbation and the UTCI value. More frequent asthma exacerbations are observed in patients aged over 65 years when air humidity increases. The UTCI values contained within class 5, describing thermoneutral conditions, correspond to an average frequency of asthma exacerbation. A decline in the UTCI value leads to a reduced number of asthma exacerbation, while a rise makes the cases of asthma exacerbations increase.

Short-term effects of multiple outdoor environmental factors on risk of asthma exacerbations: Age-stratified time-series analysis

BACKGROUND

Although the different age groups had differences in sensitivity of asthma exacerbations (AEs) to environmental factors, no comprehensive study has examined the age-stratified effects of environmental factors on AEs.

OBJECTIVE

We sought to examine the short-term effects in age-stratified groups (infants, preschool children, school-aged children, adults, and the elderly) of outdoor environmental factors (air pollutants, weather conditions, aeroallergens, and respiratory viral epidemics) on AEs.

METHODS

We performed an age-stratified analysis of the short-term effects of 4 groups of outdoor environmental factors on AEs in Seoul Metropolitan City (Korea) from 2008 and 2012. The statistical analysis used a Poisson generalized linear regression model, with a distributed lag nonlinear model for identification of lagged and nonlinear effects and convergent cross-mapping for identification of causal associations.

RESULTS

Analysis of the total population (n = 10,233,519) indicated there were 28,824 AE events requiring admission to an emergency department during the study period. Diurnal temperature range had significant effects in pediatric (infants, preschool children, and school-aged children) and elderly (relative risk [RR], 1.056-1.078 and 1.016, respectively) subjects. Tree and weed pollen, human rhinovirus, and influenza virus had significant effects in school-aged children (RR, 1.014, 1.040, 1.042, and 1.038, respectively). Tree pollen and influenza virus had significant effects in adults (RR, 1.026 and 1.044, respectively). Outdoor air pollutants (particulate matter of ≤10 μm in diameter, nitrogen dioxide, ozone, carbon monoxide, and sulfur dioxide) had significant short-term effects in all age groups (except for carbon monoxide and sulfur dioxide in infants).

CONCLUSION

These findings provide a need for the development of tailored strategies to prevent AE events in different age groups.

Effects of Meteorological Factors on Hospitalizations in Adult Patients with Asthma: A Systematic Review

Background

Environmental factors such as weather variables contribute to asthma exacerbation. The impact of meteorological factors on asthma-related hospital admissions (HAs) or emergency department visits (EDVs) has been assessed in the literature. We conducted a systematic review to establish a conclusion of whether these findings from the literature are consistent and generalizable or if they vary significantly by certain subgroups.

Objective

This study aims to review the effect of meteorological variables on asthma HAs and EDVs in adults, to identify knowledge gaps and to highlight future research priorities.

Method

A systematic search was conducted in electronic databases such as PubMed, Embase, and CINAHL. All studies published in English were screened and included if they met the eligibility criteria. Two independent reviewers assessed the quality of the studies and extracted the data. The available evidence was summarized and presented using a harvest plot.

Results

Our initial search returned a total of 3887 articles. After screening titles, abstracts, and full texts, 16 studies were included. Thirty-one percent of the included studies (5/16) found that temperature was the only factor associated with asthma hospitalization or EDVs. Six studies (37%) found that both temperature and relative humidity were associated with HAs. Four studies (25%) identified thunderstorms as a possible factor associated with asthma hospitalization in adults.

Conclusion

Our review suggests that HAs and EDVs due to asthma are associated with many meteorological factors. Among the articles included in this review, changing temperature is the most commonly studied variable. We did not find studies that measured barometric pressure, weather phenomena, or the effect of tornados. To develop effective strategies to protect subjects at risk, further studies are required.

Does air pollution really impact the onset of spontaneous pneumothorax? A French case-crossover study

RATIONALE

A link is established between air pollution and respiratory diseases. Very few studies evaluated this link with primary spontaneous pneumothorax (PSP). Contrasted results, low statistical power and methodological limits of these studies brought us to evaluate in a more thorough way this link.

OBJECTIVES

(1) to estimate the relation between PSP and air pollutants namely nitrogen dioxide (NO₂₎, ozone (O₃₎ and particulate matter with a diameter ≤ 10 μm (PM₁₀); (2) to investigate a time lag effect between these pollutants and occurrence of PSP.

METHODS

This study has a case-crossover design. Subjects aged ≥18 years admitted from 1st June 2009 to 31st May 2013, in 14 Emergency Departments centers on the French territory. Were excluded: patients with traumatic, secondary, recurrent or history of previous pneumothorax. NO₂, O₃ and PM₁₀ data were collected hourly in monitoring stations. Three exposure assessments were retained: quantitative values, fast increase concentration of air pollutants and peak of pollution. These assessments were calculated for the entire exposure period and for each of the four days of all case and control periods.

RESULTS

948 subjects included. Whatever the pollutant considered, no differences were observed between case and control periods, regardless of whether the quantitative values of air pollutants exposure (p > 0.09), fast increase concentration (p > 0.46) and peak of pollution (p > 0.20).

CONCLUSIONS

We failed to show a relation between PSP and short-term air pollution exposure to low levels of NO₂ and PM₁₀. An association between O₃ exposure and PSP cannot be ruled out. An impact at higher exposure level, and/or a potentiating effect of different meteorological factors remain to be demonstrated.

Effects of air pollution on moderate and severe asthma exacerbations

Background: Few studies have evaluated the impact of air pollution levels on the severity of exacerbations. Thus, we compared the relative risks posed by air pollutant levels on moderate and severe exacerbations.Methods: Exacerbation episodes of 618 from 143 adult asthmatics were retrospectively collected between 2005 and 2015 in a tertiary hospital of Korea. Air pollution GPS data for the location closest to each patient's home were obtained from the national ambient monitoring station. The relative impacts of air pollutants on asthma exacerbations were evaluated via a time-trend controlled symmetrical, bidirectional, case-crossover design using conditional logistic regression models on the day of the exacerbation (T-0) and up to 3 days before the exacerbation (T-1-T-3).Results: Overall asthma exacerbation were associated with O₃ levels in summer and winter (OR: 1.012[1.003-1.02] and 1.009[1.003-1.016]), SO₂ levels in spring and summer (OR: 1.009[1-1.018] and 1.02[1.006-1.035]) and NO₂ levels in winter (OR: 1.007[1.003-1.011]). Analyses of the temporal relationship between O₃ concentrations and exacerbations demonstrated that 63.2% of episodes in the summer occurred when the O₃ concentrations on T-1 were significantly higher than those on control days, while 51% of exacerbation episodes in the winter occurred. Severe and moderate exacerbations were similarly associated with O₃ levels in winter (OR: 1.012 [1.003-1.02] vs. 1.01 [0.999-1.021], p > 0.05) and in summer (OR: 1.006 [1.002-1.009] vs. 1.009 [1.003-1.016], p > 0.05).Conclusions: Asthma exacerbations may be associated with the seasonal elevation of O₃, SO₂ and NO₂ levels in summer and winter with the similar relative risk between moderate and severe exacerbations.

Effects of ambient temperature on ambulance emergency call-outs in the subtropical city of Shenzhen, China

The associations between meteorological factors and mortality have been well documented worldwide, but limited evidence is available for the non-fatal health impacts of ambient temperature, particularly there are few population-based investigations on the impacts of emergency ambulance dispatches in Asia. In this study, based on 809,906 ambulance emergency call-outs (AECOs) for the total population from 2010-2016 in the subtropical city of Shenzhen, China, a Poisson regression combined with a distributed lag nonlinear model was used to simultaneously assess the nonlinear and lag effects of daily mean temperature on AECOs. Stratified analyses by age and sex were performed to identify vulnerable subpopulations. A U-shaped relationship was found between temperature and AECOs. Cold effects were delayed and persisted for 3-4 weeks, with a cumulative relative risk (RR) and 95% confidence interval (CI) of 1.23 (1.10-1.38) and 1.25 (1.16-1.35) over lag 0-28 when comparing the 1st and 5th percentile of the temperature distribution to the optimal (i.e. minimum AECOs) temperature, respectively. Hot effects were immediate and diminished quickly in 5 days, with an increase of 19% (RR = 1.19, 95%CI: 1.14-1.23) and 21% (RR = 1.21, 95%CI: 1.16-1.26) in AECOs over lag 0-5 when comparing the 95th and 99th percentile of temperature to the optimal temperature. Children and the elderly were more vulnerable to cold effects. The youth and middle-aged people suffered more from high temperature. The effects of temperature were similar between males and females. In summary, significant increases were observed in the frequency of AECOs during cold and hot days, and the weather-associated increases in AECOs are different among age groups. This information has valuable implications in ambulance demand prediction and service provision planning.

Association between air pollution and asthma exacerbations in Badalona, Barcelona (Spain), 2008-2016

INTRODUCTION AND OBJECTIVE

Air pollution has been widely associated with respiratory diseases. Nevertheless, association between air pollution and exacerbations of asthma in our area has been less studied. To analyse the effect of air pollution on exacerbations of asthma in Badalona.

MATERIAL AND METHODS

This was an observational study conducted in Badalona. The number of daily hospital admissions and accident and emergency visits related to exacerbation of asthma between 2008 and 2016 was obtained. We used simple Poisson regressions to test the effects of daily mean temperature, atmospheric pressure, relative humidity, and NO₂, SO₂ and CO levels on asthma-related emergencies and hospitalisations the same day and 1-4 days after. All p-values were corrected for multiple comparisons.

RESULTS

The number of hospitalisations was associated with low temperature (lags 0 to 4) and higher levels of NO₂ (lags 0, 1, 2 and 4) and atmospheric pressure (lags 2 and 3). The number of accident and emergency visits was associated with low temperature (lags 0 to 4) and higher levels of NO₂ (lags 2, 3 and 4).

CONCLUSIONS

The number of accident and emergency visits and hospitalisations for exacerbation of asthma is associated with higher levels of NO₂ and with lower temperatures.

Regular follow-up visits reduce the risk for asthma exacerbation requiring admission in Korean adults with asthma

BACKGROUND

Asthma requires regular follow-up visits and sustained medication use. Although several studies have reported the importance of adherence to medication and compliance with the treatment, none to date have reported the importance of regular follow-up visits. We investigated the effects of regular clinical visits on asthma exacerbation.

METHODS

We used claims data in the national medical insurance review system provided by the Health Insurance Review and Assessment Service of Korea. We included subjects aged ≥ 15 years with a diagnosis of asthma, and who were prescribed asthma-related medication, from July 2013 to June 2014. Regular visitors (frequent visitors) were defined as subjects who visited the hospital for follow-up of asthma three or more times per year.

RESULTS

Among 729,343 subjects, 496,560 (68.1%) were classified as regular visitors. Old age, male sex, lack of medical aid insurance, attendance of a tertiary hospital, a high Charlson comorbidity index, and a history of admission for exacerbated asthma in the previous year were significant determining factors for regular visitor status. When we adjusted for all these factors, frequent visitors showed a lower risk of asthma exacerbation requiring general ward admission (odds ratio [OR] 0.48; 95% confidence interval [CI] 0.47-0.50; P < 0.001), emergency room admission (OR 0.83; 95% CI 0.79-0.86; P < 0.001), and intensive care unit admission (OR 0.49; 95% CI 0.44-0.54; P < 0.001) than infrequent visitors.

CONCLUSIONS

Regular clinical visits are significantly associated with a reduced risk of asthma exacerbation requiring hospital admission in Korean adults with asthma.

Association between the length of the MUC8-minisatellite 5 region and susceptibility to chronic obstructive pulmonary disease (COPD)

In asthma and chronic obstructive pulmonary disease (COPD), mucins display disease-related alterations caused by airway mucus obstruction. MUC5AC, MUC5B and MUC8 are known as the major secretory mucins in human airway epithelial cells. Analysis of mucin genes has identified the presence of several features with a variable number of tandem repeats (VNTR; minisatellites) in the central region of each mucin. In our previous study, six minisatellites in the region of the MUC8 gene were identified, and the MUC8-MS5 minisatellite showed the highest heterozygosity among them. In this study, we evaluated the relationship between MUC8-MS5 and susceptibility to asthma and COPD. A case-control study was performed with 229 controls, 123 COPD cases and 77 asthma cases. A significant association (OR 3.96) between short alleles (2/2 repeats) and the occurrence of COPD was observed [95% confidence interval (CI) 1.32-11.88; p = 0.008]. Hence, the increased frequency of 2/2 homo-short alleles were also found in asthma cases (3.11; CI 0.88-11.05; p = 0.066), though this association was not statistically significant. These results revealed a genetic association between MUC8 and COPD, and that the specific short minisatellite alleles (2/2) of MUC8-MS5 may be a risk factor for COPD.