A time for everything and everything in its time – exploring the mechanisms underlying seasonality of COPD exacerbations

Abstract

Alexander Hicks,1–3 Eugene Healy,1 Natasha Sandeman,1 Martin Feelisch,1,2 Tom Wilkinson1–4 1Clinical and Experimental Sciences, University of Southampton – Faculty of Medicine, Southampton General Hospital, Southampton, UK; 2Southampton NIHR Respiratory Biomedical Research Centre, Southampton General Hospital, Southampton, UK; 3National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care (NIHR CLAHRC) Wessex, Southampton General Hospital, Southampton, UK; 4Wessex Investigational Sciences Hub, University of Southampton – Faculty of Medicine, Southampton General Hospital, Southampton, UK Abstract: Across Europe, COPD affects 23 million people leading to annual health care costs of ~€25.1 billion. This burden is particularly severe during winter months in association with the peak incidence of exacerbation events. Seasonal variation in the health status of patients with COPD places additional and often critical pressure on already strained health care resources. COPD exacerbations are characterized by worsening day-to-day symptoms of an individual and often triggered by respiratory infections, but the process by which this occurs in a seasonal fashion is likely to be multifactorial. In this review, we discuss recent population studies that highlight the impact of seasonality in COPD and review the proposed biological mechanisms underlying this. An appraisal of the role of the host susceptibility and response, environmental triggers and the biology of respiratory pathogens is detailed. The impact of each aspect is considered, and an integrated model of the context for the whole individual and society in general is explored. Keywords: COPD exacerbation, seasonality, pollution, weather

Keywords

• COPD
• Exacerbation
• Seasonality
• Immunity
• Climate
• Pollution