Fractional exhaled nitric oxide was not associated with the future risk of exacerbations in Chinese asthmatics: a non-interventional 1-year real-world study.

Background: Exacerbations are recognized as the most relevant predictor of future risk in asthmatics. We aimed to evaluate the association between asthma exacerbations, fractional exhaled nitric oxide (FENO), spirometry indices, and other potential risk factors in a non-interventional, real-world study performed in Guangzhou, China.

Methods: We performed a prospective 12 months follow-up of Chinese asthmatics. Spirometry and FENO measurements were performed at baseline. Adherence to inhaled corticosteroids (ICS) use was divided into two categories (>80% and <80%). Patients were seen 4 times after the initial baseline visit.

Results: A total of 222 patients with asthma (49.1% males) completed the study, of which 51 (23.0%) experienced exacerbations during the study period. Of the patients, 117 (52.7%) had good compliance. We compared lung function indices between the patients with and without exacerbations. There was no difference of forced expiratory volume in 1 s (FEV1) predicted, forced vital capacity (FVC) predicted, and FEVI/FVC (all, P>0.05) between the groups. There was also no significant difference in FENO level between the two groups. Compared to those that had exacerbations, patients without exacerbations had better treatment compliance (P<0.001). Logistic regression analysis identified an association between asthma exacerbations, poor control of symptom [odds ratio (OR) =2.295; 95% confidence interval (CI): 1.130-4.663; P=0.022], and nonadherence to asthma medications (OR =4.718; 95% CI: 2.149-10.359; P<0.001).

Conclusions: Poor adherence rather than baseline FENO and FEV1% predicted was associated with the future risk of exacerbations in Chinese asthmatics in real world.