Identification of asthma phenotypes based on extrapulmonary treatable traits

Abstract

BackgroundAsthma is a heterogeneous and complex disease, and the description of asthma phenotypes based on extrapulmonary treatable traits has not been previously reported.Objectiveto identify and characterise clusters based on clinical, functional, anthropometrical, and psychological characteristics in participants with moderate-to-severe asthma.MethodsThis is a cross-sectional multicentre study involving centres from Brazil and Australia. Participants (N=296) with moderate-to-severe asthma were consecutively recruited. Physical activity and sedentary time, clinical asthma control, anthropometric data, pulmonary function, psychological, and health-status were evaluated. Participants were classified by hierarchical cluster analysis and the clusters compared using ANOVA, Kruskal-Wallis, and Chi-square tests. Multiple logistic and linear regression models were performed to evaluate the association between variables.ResultsWe identified four clusters: (1)controlled asthma who were physically active, (2)uncontrolled asthma who were physically inactive and more sedentary, (3)uncontrolled asthma with low physical activity, who were also obese and experienced anxiety and/or depression symptoms (4)very uncontrolled asthma, who were physically inactive, more sedentary, obese and experienced anxiety and/or depression symptoms. Higher levels of sedentary time, female sex, and anxiety symptoms were associated with increased odds of exacerbation risk while being more active showed a protective factor for hospitalisation. Asthma control was associated with sex, the occurrence of exacerbation, physical activity, and health-status.ConclusionTraits such as physical inactivity, obesity, and symptoms of anxiety and/or depression were associated with worse asthma outcomes, and closely and inextricably with asthma control. This cluster analysis supports the importance of assessing extrapulmonary traits to improve personalised management and outcomes for people with moderate and severe asthma.