New Perspectives on Difficult Asthma; Sex and Age of Asthma-Onset Based Phenotypes
Adnan Azim, Anna Freeman, Audrey Lavenu, Heena Mistry, Hans Michael Haitchi, Colin Newell, Yueqing Cheng, Yvette Thirlwall, Matthew Harvey, Clair Barber, Katarina Pontoppidan, Paddy Dennison, S Hasan Arshad, Ratko Djukanovic, Peter Howarth, Ramesh J Kurukulaaratchy, Adnan Azim, Anna Freeman, Audrey Lavenu, Heena Mistry, Hans Michael Haitchi, Colin Newell, Yueqing Cheng, Yvette Thirlwall, Matthew Harvey, Clair Barber, Katarina Pontoppidan, Paddy Dennison, S Hasan Arshad, Ratko Djukanovic, Peter Howarth, Ramesh J Kurukulaaratchy
Abstract
Background: Asthma is a diverse condition that differs with age and sex. However, it remains unclear how sex, age of asthma onset, and/or their interaction influence clinical expression of more problematic adult "difficult" asthma.
Objectives: To better understand the clinical features of difficult asthma within a real-world clinical setting using novel phenotypic classification, stratifying subjects by sex and age of asthma onset.
Methods: Participants in a longitudinal difficult asthma clinical cohort study (Wessex AsThma CoHort of difficult asthma; WATCH), United Kingdom (n = 501), were stratified into 4 difficult asthma phenotypes based on sex and age of asthma onset (early <18 years or adult ≥18 years) and characterized in relation to clinical and pathophysiological features.
Results: The cohort had more female participants (65%) but had similar proportions of participants with early- or adult-onset disease. Early-onset female disease was commonest (35%), highly atopic, with good spirometry and strong associations with some physical comorbidities but highest psychophysiologic comorbidities. Adult-onset females also had considerable psychophysiologic comorbidities and highest obesity, and were least atopic. Amongst male subjects, proportionately more had adult-onset disease. Early-onset male disease was rarest (14%) but associated with worst lung function, high smoking, atopy, and fungal sensitization. Despite shortest disease duration, adult-onset males had highest use of maintenance oral corticosteroid, poor lung function, and highest fractional exhaled nitrogen oxide in spite of highest smoking prevalence.
Conclusions: This study shows that sex, age of asthma onset, and their interactions influence different clinical manifestations of difficult asthma and identifies a greater risk for lung function loss and oral corticosteroid dependence associated with smoking in adult-onset male subjects.
Keywords: Age of onset; Comorbidity; Difficult asthma; Lung function; Phenotypes; Sex; Smoking.
Crown Copyright © 2020. Published by Elsevier Inc. All rights reserved.
Source: PubMed