Understanding Breathlessness Burden and Psychophysiological Correlates in Asthma.

ABSTRACT

BACKGROUND: Breathlessness is a disabling symptom, with complexity that is often under-recognized and undertreated in asthma. OBJECTIVE: To highlight the burden of breathlessness in people with severe compared with mild-to-moderate asthma and identify psychophysiological correlates of breathlessness. METHODS: This was a cross-sectional study of people with mild-to-severe asthma, who attended 2 in-person visits to complete a multidimensional assessment. The proportion of people with mild-to-moderate versus severe asthma who reported physically limiting breathlessness (modified Medical Research Council [mMRC] dyspnea score ≥2) was compared. Psychophysiological factors associated with breathlessness in people with asthma were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness. RESULTS: A total of 144 participants were included, of whom, 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma. Participants were predominantly female (n = 103, 72%) with a median (quartile 1, quartile 3) age of 63.4 (50.5, 69.5) years and body mass index (BMI) of 31.3 (26.2, 36.0) kg/m2. The proportion of people reporting mMRC ≥2 was significantly higher in those with severe- (n = 37, 53%) than those with mild-to-moderate (n = 21, 31%) asthma (P = .013). Dyspnoea-12 Total (8.00 [4.75, 17.00] vs 5.00 [2.00, 11.00], P = .037) score was also significantly higher in the severe asthma group. Significant predictors of physically limiting breathlessness were BMI, asthma control, exercise capacity, and hyperventilation symptoms. Airflow limitation and type 2 inflammation were poor breathlessness predictors. CONCLUSIONS: Over half of people with severe asthma experience physically limiting breathlessness despite treatment. Targeting psychophysiological factors, or traits, associated with breathlessness may help relieve this distressing symptom, which is of high priority to people with asthma.