Impact of Air Pollution on Daily Asthma Symptoms.

INTRODUCTION: The impact of air pollution on respiratory diseases, particularly in asthma, has been the subject of several studies. The impact of pollution on the daily symptoms of patients with asthma has been less studied. The aim of this study is to assess the association between the intensity of asthma symptoms and the variation of pollution levels. MATERIAL AND METHODS: Patients with a diagnosis of asthma were instructed to record the intensity of their respiratory symptoms daily, expressed on a scale from 0 to 5, in the months of March and April 2018. The website of the Portuguese Environment Agency was consulted in order to obtain the daily levels of pollutants measured by the two local monitoring stations during the same period of time. Data was analyzed using a temporal causal model to study the association between pollutant levels - particulate matter, ozone, nitrogen dioxide and carbon monoxide - and the intensity of respiratory symptoms. RESULTS: From the 135 schedules delivered, 35 were correctly filled out and returned. The patient median age was 47.0 years, 18 being females. The best statistical model obtained identified ozone as the most relevant 'Granger cause' of asthma symptoms. Particulate matter, carbon monoxide and nitrogen also appeared as lower impact factors. The quality of the model was expressed by an R2 of 0.92. The correlation between ozone values and asthma symptoms was more significant after five days. For the other identified factors there was a lag of four to five days. DISCUSSION: Our results support the existence of a daily variation of asthma symptoms that is associated with the pollution levels, even if these are within acceptable limits according to national and international standards. Regretfully, the small number of participants was a limitation in term of the conclusions that could be drawn and did not allow the analysis of clinical or other factors that are potentially involved. CONCLUSION: In the place and period studied the air pollutants behaved as factors of variation in the intensity of asthma symptoms. The ozone level was the best predictive factor of symptom variation. Levels of particulate matter, carbon monoxide and nitrogen were identified as secondary markers. The time lag between the variables with the best correlation suggests there could be a delayed effect of pollutants on respiratory symptoms.

Introdução: O impacto da poluição atmosférica nas doenças respiratórias, nomeadamente na asma, tem sido objeto de numerosos estudos. A repercussão da poluição na sintomatologia diária dos doentes asmáticos tem sido menos estudada. Pretendemos estudar a relação entre a intensidade dos sintomas diários de asma e a variação dos níveis de poluição. Material e Métodos: Foram selecionados doentes com diagnóstico de asma, sendo instruídos para anotar diariamente a intensidade dos seus sintomas respiratórios, expressa numa escala de 0 a 5, nos meses de março e abril de 2018. O website da Agência Portuguesa do Ambiente foi consultado e registaram-se os níveis diários de poluentes medidos pelas duas estações locais de monitorização durante o mesmo período. Os dados foram analisados utilizando um modelo causal temporal com a finalidade de relacionar os níveis de poluentes ­ partículas inaláveis com diâmetro menor que 10 µm, ozono, dióxido de nitrogénio e monóxido de carbono - com a intensidade dos sintomas de asma dos doentes. Resultados: Dos 135 calendários entregues, 35 foram corretamente preenchidos e devolvidos. A mediana de idades dos doentes foi de 47,0 anos, sendo 18 do sexo feminino. O melhor modelo estatístico obtido identificou o ozono como a 'causa Granger' mais relevante para os sintomas de asma. A qualidade do modelo traduziu-se por um R2 de 0,92. A correlação entre os valores de ozono e os valores dos sintomas de asma foi mais significativa após cinco dias. Para os outros fatores identificados verificou-se um desfasamento de quatro a cinco dias. Discussão: Os nossos resultados sugerem, de forma significativa, uma relação entre a variação dos sintomas de asma e os níveis de poluição, mesmo dentro dos limites considerados aceitáveis pelos padrões nacionais e internacionais. A reduzida dimensão da amostra foi, no entanto, um fator limitativo das conclusões e não permitiu a análise de outras varáveis potencialmente envolvidas. Conclusão: No período e local estudados, os poluentes atmosféricos comportaram-se como fatores de variação da intensidade dos sintomas de asma. O nível de ozono foi o melhor fator preditivo das variações da sintomatologia. Os níveis de partículas inaláveis, com diâmetro menor que 10 µm, de monóxido de carbono e de dióxido de nitrogénio foram identificados como marcadores secundários. O desfasamento temporal entre as variáveis com melhor correlação sugere um possível efeito retardado dos poluentes sobre os sintomas respiratórios.

Understanding and Managing Severe Asthma in the Context of COVID-19.

Coronavirus disease 2019 (COVID-19) continues to spread across the world. Since the beginning of the pandemic, the question of whether asthma is a risk factor for getting the infection or for poor outcomes motivated a great debate. In the field of severe asthma and its treatment during COVID-19 pandemic, several issues are also pending. A literature review focused on the management of severe asthma patients in the context of COVID-19 is performed. The available evidence suggests that severe asthma patients do not have an increased risk of poor COVID-19 outcomes and that it is safe to treat asthmatic patients with inhaled corticosteroids (ICS) and biologics during the pandemic, even though some studies indicate that high doses of ICS may predispose to COVID-19. The chronic use of oral corticosteroid (OCS) might be associated with poor COVID-19 outcomes, although there is no complete agreement. There is very limited evidence concerning the use of triple therapy for asthma in the context of this pandemic. Ultimately, severe asthma patients should maintain their medication during the COVID-19 pandemic, including biologic agents. More studies are needed to address the role of asthma medications and asthma's different phenotypes on the incidence and course of COVID-19.