Understanding breathlessness in asthma: cross-sectional study on breathlessness burden and psychophysiological correlates

<bold>Objectives:</bold> Chronic breathlessness in asthma is underrecognised and often untreated. This study aimed to: 1) Determine the burden of breathlessness in severe vs mild-to-moderate asthma 2) Identify psychophysiological correlates of breathlessness in asthma <bold>Methods:</bold> People with mild-to-severe asthma completed a multidimensional assessment. The proportion of people with mild-to-moderate vs severe asthma who reported breathlessness (modified Medical Research Council dyspnoea score ≥2) was compared. Psychophysiological correlates of breathlessness were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness; odds ratios (OR) with 95%CI were reported. <bold>Results:</bold> 144 participants were included; 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma (72% female; median [IQR] age 63 [51-70] years). Breathlessness prevalence was significantly higher in severe (53%) vs mild-to-moderate (31%) asthma (p=0.013). Psychophysiological factors that best predicted breathlessness were higher BMI (OR [95%CI]=1.13 [1.03, 1.25]), and worse asthma control (Asthma Control Questionnaire-7; 1.87 [0.92, 4.16]), exercise capacity (6MWD %pred; 0.92 [0.86, 0.97]), and hyperventilation symptoms (Nijmegen; 1.13 [1.03, 1.25]). Airflow limitation and type-2 inflammation were poor breathlessness predictors. <bold>Conclusion:</bold> Over half of people with severe asthma experience breathlessness. Airflow limitation and type-2 inflammation, which are often the focus on personalised management, were poor breathlessness predictors. Targeting traits associated with breathlessness may be more effective to help relieve this disabling symptom.