Airway wall thickness in patients with uncontrolled asthma

ABSTRACT

Asthma is characterized by chronic inflanmation and structural changes in the airulays referred to as remodeling. Recently, high resolution CT [HRCT] has been used to indirectly assess ainuay remodeling in vi-rro, on the basis of findings such as aintlay wall thickening. 1] To assess ainnray wall thickness by HRCT in patients with uncontrolled and partly controlled asthma arid to compare these findings with norrnal healthy controls, 2] to investigate the association behrwen disease duration and the degree of airflow limitation and airflow wall thickness parameters. Prospective case- control study Fifty -koo patients ulith asthma and 23 healthy controls ulere recruited in the study. We measured ainuay luminal area [Ai] corrected by body surface area [Ai/ BSA], airway wall area [WA] corrected by body surface area [wA/BSA], the percentage of wall area [WA%], absolute wall thickness [T]/BSA, and thickness to diameter ratio [TDR] by HRCT. Spironietric tests were also perfomred. In patients with uncontrolled and partly controlled asthma, Ai/ BSA, WA/BSA, WA%, and T/BSA were all significantly greater than those in controlled and healthy control srrbjects. No significant difference in airway wall thickness paranieters were found between controlled asthmatics and healthy controls. The degree of airway wall thickness was correlated to smoking, disease duration and percentage of predicted forced vital capacity [FVC%], forced expiratory volume in 1st second [FEV1%] and FEV1/FVC and post-bronchodilator reversibility in asthmatics. The airways of uncontrolled and partly controlled asthmatics are thickened when compared to controlled asthmatics and healthy controls. Smoking and prolonged disease duration may be important factors in determining the airway wall thickness and hence the irreversibility of airway obstruction in this group of patieirts