Reduced bronchodilator reversibility correlates with non-type 2 high asthma and future exacerbations: A prospective cohort study.

BACKGROUND

Given that airway obstruction in asthma is not always fully reversible, reduced bronchodilator reversibility (BDR) may be a special asthma phenotype.

OBJECTIVE

To explore the characteristics of BDR phenotypes (defined using two BDR criteria) and their associations with asthma exacerbations (AEs).

METHODS

After baseline assessments, all patients were classified into BDR or BDR phenotypes. This study consisted of 2 parts. Part I was a 12-month prospective observational cohort study designed to identify the clinical characteristics and associations with future AEs in BDR phenotypes (n = 456). Part II, designed as a post hoc analysis of the data obtained in Part I, was conducted to assess the association between BDR phenotypes and treatment responsiveness (n = 360).

RESULTS

Subjects with BDR phenotypes had better baseline asthma symptom control and was negatively associated with eosinophilic asthma and type 2 (T2) high asthma. During the 12-month follow-up, those with BDR phenotypes had a higher risk of severe AEs (SAEs) (guideline-based criterion: RR = 2.24, 95% CI = [1.25, 3.68]; Ward's criterion: RR = 2.46, 95% CI = [1.40, 4.00]) and moderate-to-severe AEs (MSAEs) (guideline-based criterion: RR = 1.83, 95% CI = [1.22, 2.56]; Ward's criterion: RR = 1.94, 95% CI = [1.32, 2.68]) in the following year according to logistic regression models. Similar findings were obtained with negative binominal regression models. BDR phenotype was a risk factor for an insensitive response to anti-asthma treatment (guideline-based criterion: OR = 1.96, 95% CI = [1.05, 3.65]; Ward's criterion: OR = 2.01, 95% CI = [1.12, 3.58]).

CONCLUSION

We identified that BDR phenotype was associated with non-T2 high asthma and future AEs. These findings have clinically relevant implications for asthma management.