Risk factors related to fixed airway obstruction in patients with asthma after antiasthma treatment.

BACKGROUND

There are many unanswered questions about the role of airway remodeling in asthma.

OBJECTIVE

To evaluate the physiologic factors related to airway remodeling after antiasthma drug treatment for 1 year.

METHODS

We gave 582 patients with asthma long-term control medication for 1 year according to the severity of their asthma. Airway remodeling was defined using forced expiratory volume in 1 second/forced vital capacity and a predicted forced expiratory volume in 1 second of less than 75% after antiasthma treatment.

RESULTS

Of the 582 patients, 49 (8.4%) had airway remodeling. Severe asthma resulted in more airway remodeling than mild-to-moderate asthma. Asthmatic patients with airway remodeling were significantly older and had a longer duration of asthma. Asthmatic patients with airway remodeling had more emphysema on high-resolution computed tomography, a higher rate of near-fatal asthma attacks, a lower percentage of sputum eosinophils, a lower atopy frequency, a greater response to short-acting bronchodilators, and a lower body mass index (BMI) than those without airway remodeling. Age, asthma duration, and BMI were important discriminators of airway remodeling.

CONCLUSION

Nonatopy, asthma duration, emphysema on high-resolution computed tomography, sputum eosinophils, age, and BMI before antiasthma treatment are important factors related to airway remodeling in patients with asthma.