Differences in the effects of Asian dust on pulmonary function between adult patients with asthma and those with asthma-chronic obstructive pulmonary disease overlap syndrome

Association Between Asian Dust Exposure and Pneumonia Hospitalization in Western Japan: A Case-Crossover Study

Epidemiological studies have reported that Asian dust (AD), a type of desert dust, has harmful effects on human health. This study aimed to examine the association between AD exposure and hospitalization due to pneumonia. Data on patients in Western Japan admitted for pneumonia were included from a real-world database derived from electronic medical records. We used the meteorological observatory data of the most populous city in each prefecture, in which AD event was defined as a loss of visibility from a distance ≤10 km. A case-crossover design and conditional logistic regression model were used. Overall, 12 938 patients were included, and AD exposure events were observed for 557 days. Exposure to an AD event five days prior to hospitalization was significantly associated with hospitalization for pneumonia after adjusting for weather variables (odds ratio = 1.17). These findings suggest that AD exposure is associated with an increased rate of admission for pneumonia in Western Japan.

Global Health Impacts of Dust Storms: A Systematic Review

BACKGROUND

Dust storms and their impacts on health are becoming a major public health issue. The current study examines the health impacts of dust storms around the world to provide an overview of this issue.

METHOD

In this systematic review, 140 relevant and authoritative English articles on the impacts of dust storms on health (up to September 2019) were identified and extracted from 28 968 articles using valid keywords from various databases (PubMed, WOS, EMBASE, and Scopus) and multiple screening steps. Selected papers were then qualitatively examined and evaluated. Evaluation results were summarized using an Extraction Table.

RESULTS

The results of the study are divided into two parts: short and long-term impacts of dust storms. Short-term impacts include mortality, visitation, emergency medical dispatch, hospitalization, increased symptoms, and decreased pulmonary function. Long-term impacts include pregnancy, cognitive difficulties, and birth problems. Additionally, this study shows that dust storms have devastating impacts on health, affecting cardiovascular and respiratory health in particular.

CONCLUSION

The findings of this study show that dust storms have significant public health impacts. More attention should be paid to these natural hazards to prepare for, respond to, and mitigate these hazardous events to reduce their negative health impacts.Registration: PROSPERO registration number CRD42018093325.

Health Effects of Asian Dust: A Systematic Review and Meta-Analysis

BACKGROUND

Potential adverse health effects of Asian dust exposure have been reported, but systematic reviews and quantitative syntheses are lacking.

OBJECTIVE

We reviewed epidemiologic studies that assessed the risk of mortality, hospital admissions, and symptoms/dysfunction associated with exposure to Asian dust.

METHODS

We performed a systematic search of PubMed and Web of Science to identify studies that reported the association between Asian dust exposure and human health outcomes. We conducted separate meta-analyses using a random-effects model for mortality and hospital admissions for a specific health outcome and assessed pooled estimates for each lag when at least three studies were available for a specific lag.

RESULTS

We identified 89 studies that met our inclusion criteria for the systematic review, and 21 studies were included in the meta-analysis. The pooled estimates (percentage changes) of mortality from circulatory and respiratory causes for Asian dust days vs. non-Asian dust days were 2.33% [95% confidence interval (CI): 0.76, 3.93] increase at lag 0 and 3.99% (95% CI: 0.08, 8.06) increase at lag 3, respectively. The increased risk for hospital admissions for respiratory disease, asthma, and pneumonia peaked at lag 3 by 8.85% (95% CI: 0.80, 17.55), 14.55% (95% CI: 6.74, 22.94), and 8.51% (95% CI: 2.89, 14.44), respectively. Seven of 12 studies reported reduced peak expiratory flow, and 16 of 21 studies reported increased respiratory symptoms associated with Asian dust exposure. There were substantial variations between the studies in definitions of Asian dust, study designs, model specifications, and confounder controls.

DISCUSSION

We found evidence of increased mortality and hospital admissions for circulatory and respiratory events. However, the number of studies included in the meta-analysis was not large and further evidences are merited to strengthen our conclusions. Standardized protocols for epidemiological studies would facilitate interstudy comparisons. https://doi.org/10.1289/EHP5312.

[Health Effects of Asian Dust Events: A Literature Review Update of Epidemiological Evidence]

Asian dust is a phenomenon involving the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. In recent years, the health effects of Asian dust have raised public concerns. Numerous studies on the health effects of Asian dust have been published since the last review in 2010. Thus, a literature review was conducted to shed light on the latest epidemiologic findings. PubMed and Science Direct databases were used for the review of epidemiologic studies published between June 2009 and April 2018. We identified 53 epidemiologic studies. Mortality, ambulance transportation, hospitalization/medical examination, changes in symptomatic, functional, and examination findings, as well as birth outcomes have been reported as outcomes. When the outcomes were categorized by disease, the effects of Asian dust on respiratory, cardiovascular, and allergic diseases raised concerns. The common evidences of causation between Asian dust and these diseases were the consistency of findings and temporal sequence of association. As results of research on dose-response relationships have become available, and the possibility that the health effects of Asian dust may vary depending on its chemical composition has been pointed out, further research using the exposure level indicators of Asian dust or its chemical composition should be conducted. Furthermore, with focus on the crucial issue of reducing exposure, research related to prevention and raising awareness should be further promoted.

Global prevalence of asthma-COPD overlap (ACO) in the general population: a systematic review and meta-analysis

Background

Asthma-COPD overlap (ACO) is a term that encompasses patients with features of both asthma and COPD. To date, the global prevalence of ACO in the general population remains unknown. The objective of this study was to estimate the prevalence of ACO in the general population using a systematic review and meta-analysis.

Methods

A systematic search of ISI Web of Knowledge, MEDLINE/PubMed, and Scopus was performed up to May 2019 to identify studies reporting the prevalence of ACO. Reference lists from identified studies and relevant review articles were also searched. Eligibility criteria were studies reporting the prevalence of ACO, performed in general population, and published in English language. Pooled prevalence of ACO with 95% confidence interval (CI) was calculated using random effects Meta-analysis.

Results

A total of 27 studies were included in this meta-analysis. The Cochran Q test and I² statistics revealed substantial heterogeneity among studies. Based on the random-effects model, the pooled prevalence of ACO was 2.0% (95% CI: 1.4–2.6%) in the general population, 26.5% (95% CI: 19.5–33.6%) among patients with asthma, and 29.6% (95% CI: 19.3–39.9%) among patients with COPD. In addition, for included studies, the global prevalence of asthma-only was 6.2% (95% CI: 5.0–7.4%) and COPD-only was 4.9% (95% CI: 4.3–5.5%).

Conclusion

We estimated the global prevalence of ACO based on population-based studies and found that 2.0% of the general population is affected. However, the prevalence of ACO depends on its diagnostic criteria. Therefore, there is a vital need to better define the ACO diagnostic criteria, management and treatment. It is worth noting that the limitations of the present study include lack of studies in some region of the world and small number of studies included in the subgroup analyses.

Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.

Association of air pollution with increased incidence of ventricular tachyarrhythmias recorded by implantable cardioverter defibrillators: Vulnerable patients to air pollution

BACKGROUND

This study investigated the acute effects of exposure to air pollution on ventricular tachyarrhythmias (VTAs) in an East Asian population. The association between air pollution and VTA has not yet been studied in an East Asian country affected by the Asian dust phenomenon, which worsens air quality.

METHODS

The study cohort consisted of 160patients with implantable cardioverter defibrillator (ICD) devices in the Seoul metropolitan area who were followed for 5.5±3.8years. We used ICD records of VTAs and matched these with hourly measurements of air pollutant concentrations and meteorological data. Fine particle mass and gaseous air pollution plus temperature and relative humidity were measured hourly during the study period.

RESULTS

During the study period, 1064 VTA events including 204 instances of ventricular fibrillation (VF) were observed. We found a statistically significant association between overall VTA events and SO₂ (lag 24h; OR 1.49, 95%CI 1.16-1.92, p=0.002), PM₁₀ (lag 2h; OR 2.56, 95%CI 2.03-3.23, p<0.001), NO₂ (lag 24h; OR 1.25, 95%CI 1.19-1.31, p<0.001) and CO (lag 24h; OR 1.05, 95%CI 1.02-1.08, p=0.003). Sustained ventricular tachycardia or VF was also independently associated with SO₂, PM₁₀, NO₂ and CO (all p<0.01). Exposures to SO₂, PM₁₀, NO₂, and CO (all p<0.01) were significantly related to overall VTAs, especially in patients with structural heart disease (SHD).

CONCLUSIONS

Associations between air pollution and VTA were observed in a metropolitan area of an East Asian country. Exposures to SO₂, PM₁₀, NO₂, and CO were significantly associated with VTAs in ICD patients with SHD.