Clinical and spirometric features of asthma patients with fixed airway obstruction

Abstract

Background: Asthma is generally characterized by reversible airway obstruction. However, some asthma patients demonstrate fixed airway obstruction (FAO) despite optimal treatment. The aim of this study is to assess the relationship between FAO and clinical features of asthma and the effect of FAO on treatment response. Methods: A cross-sectional study including asthma patients was conducted between January and December 2016. Spirometry was performed on all patients. Patients with post bronchodilator FEV1/FVC ratio ≤ 70% at two annual consecutive visits were considered with FAO. Patients with concomitant chronic obstructive pulmonary disease were excluded. We compared two groups: group 1 (G1) with FAO and group 2 (G2) without FAO. Results: Of the total of 204 patients, 17% had FAO. Mean age was higher in G1 (49.6 vs 44 years, p=0.04). Male predominance was seen in G1 (58% vs 47%, p=0.2). There were no difference on BMI between the two groups. Smoking history was frequent, but higher in G1 (60% vs 51%, p=0.3). Gastro oesophageal reflux was more frequent in G1 (37% vs 34%, p=0.8). Allergic asthma was predominant in the two groups. FEV1 was lower in G1 (68% vs 88%, p=0.01). Well control asthma control was more frequent in G2 (45% vs 65%, p=0.03). Exacerbations of asthma in the previous year were more frequent in G1 (77% vs 53%, p=0.01). Association of high dose of inhaled corticosteroid with inhaled long acting beta agonist was more frequent in G1 (20% vs. 6%, p=0.01). Conclusion: Tunisian asthmatics with FAO tended to be male, elderly and smokers. These patients had severe asthma requiring a high dose of inhaled treatment.