Exacerbations among patients with asthma are largely dependent on the presence of multimorbidity

Abstract

Comorbidities can influence asthma control and promote asthma exacerbations (AE). However, the impact of multimorbidity in AE, through long-term follow-up in patients with asthma of different severity has been scarcely studied in real-life conditions. Objective: To describe the epidemiological and clinical characteristics and predictive factors of AE in patients who had presented at least one AE in the last year among patients recruited in the MEchanism of Genesis and Evolution of Asthma (MEGA) project. Methods: We carried out a detailed clinical examination, pulmonary function testing, fractional exhaled nitric oxide (FeNO), blood counts, induced sputum, skin prick-tests, asthma questionnaires, and multimorbidity assessment. For each subject, the number of moderate-severe AE in the preceding year was registered. Results: 486 patients with asthma were included (23.7% mild, 35% moderate, 41.3% severe). 41.9% remained uncontrolled. 47.3% presented ≥1 moderate-severe AE, with mean annual exacerbation rate of 0.47±0.91 vs 2.11±2.82 in mild and severe asthma, respectively. 56.4% (66.6% among severe asthmatics) presented some comorbidity. Bronchiectasis, chronic rhinosinusitis with nasal polyps, atopy, psychiatric illnesses, hyperlipidaemia and hypertension were significantly related with AE. No associations were found for FeNO, blood eosinophils and total serum IgE. Sputum eosinophilia and a high-T2 inflammatory pattern were significantly associated with AE. Multivariable regression analysis showed significant association with asthma severity, uncontrolled disease and low pre-bronchodilator FEV1/FVC. Conclusions: The MEGA cohort found a high AE rate, which was strongly associated with multimorbidity, asthma severity, poor asthma control, airflow obstruction, higher sputum eosinophils and a very high T2-inflammatory pattern.